MP3 Trigger

Make some noise with your next project! The MP3 Trigger board is built to make it MP3 sound integration easier than ever. The board has 18 external trigger pins that will directly trigger pre-selected MP3 tracks, and a full-duplex serial control port that provides full transport control, remote triggering for up to 256 tracks, and fast real-time volume control. MP3s are stored on FAT16 formatted SDSC or FAT32 formatted SDHC micro-SD flash memory cards. In addition, optimized code now achieves 192Kbps stereo playback from a wider range of cards than before.

The heart of the MP3 Trigger board is the Cypress PSoC CY8C29466-24SXI microcontroller which serves up MP3 data to a VLSI VS1063 audio codec IC. This version also supports an optional initialization file that can be used to set the serial port baud rate as well as to reprogram any of the 18 trigger inputs to alternate functions, including random and sequential track selection, transport controls and even volume up/down. Each conventional trigger can be set to either allow immediate restarts, or to lock out restarts if audio is playing. Also, a new trigger filename convention provides greater flexibility in naming your MP3 tracks and makes file management easier.

There is also a “Quiet Mode” feature that can be enabled via the serial control port. In this mode, the trigger inputs don’t start tracks directly, but instead produce a serial message indicating which triggers were activated. A host microcontroller can thus monitor the trigger inputs and then start any track or sequence of tracks via the serial control port, making the triggers much more flexible.

Check the link in the documents below to keep up with the latest Firmware updates!

Note: The MP3 Trigger supports both SDSC (up to 2GB) and SDHC (up to 32GB) type microSD cards.

Note: This product is a collaboration with Robertsonics. A portion of each sales goes back to them for product support and continued development.

  • Input voltage: 4.5-12VDC
  • Current Consumption: 45mA idle, 85mA playing
  • File system: FAT16/FAT32
  • Audio out: 1/8" stereo headphone
  • Trigger inputs: 3.3-5V, active low inputs with internal pull-ups
  • Serial: Full duplex, 8N1, 38.4K baud

MP3 Trigger Product Help and Resources

Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

2 Soldering

Skill Level: Rookie - The number of pins increases, and you will have to determine polarity of components and some of the components might be a bit trickier or close together. You might need solder wick or flux.
See all skill levels

Core Skill: Programming

If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.

3 Programming

Skill Level: Competent - The toolchain for programming is a bit more complex and will examples may not be explicitly provided for you. You will be required to have a fundamental knowledge of programming and be required to provide your own code. You may need to modify existing libraries or code to work with your specific hardware. Sensor and hardware interfaces will be SPI or I2C.
See all skill levels

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

2 Electrical Prototyping

Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Member #750947 / about 9 years ago / 1

    Hi folks! I'm trying to build a drum trigger/metronome combo system that I can use in tandem with acoustic microphones. I'd like to be able to upload my own bass drum and metronome sounds. Should I use this or the WAV Trigger? Sounds like WAV Trigger is what I want.

    • robertsonics / about 9 years ago / 1

      There's a whole bunch of things that the WAV Trigger can do that the MP3 Trigger can't, the main things being polyphony, CD quality, uncompressed audio and MIDI. The only thing the MP3 Trigger can do that the WAV Trigger can't is play MP3 files, but you can easily convert any MP3 to wav. I don't know why you wouldn't use the WAV Trigger.

  • Member #736768 / about 9 years ago / 1

    Hello, New to the site and this type of work as well. Here is my customers request. We built a fancy TV into a real fancy cabinet. He wants it to play a certain song while it is rising out of the cabinet, (ride of the valkyries by wagner!!). I assume I can use this item with a small amplifier and speaker. Just not sure how to trigger it?? Can I use a magnetic alarm switch? And where/how do you trigger this item? There is power in the cabinet for a power pack etc. Thanks, Great website. Mark

  • zlp / about 11 years ago * / 7

    There are two big problems with this otherwise great board:

    No line-out is a pain: I put a diagram on my website of the simplest way to get a functional & safe output from the board. (Nothing original here, just the info from the Sparkfun schematic + VLSI appnote, turned into a pretty picture.) Sparkfun: feel free to add the image to the product description if you think it'll help.

    False-triggers on long cable runs: I've had major problems (random triggers & cross-talk) if my button cables are longer than about 2ft. The solution is a 1k pull-up resistor at the output of the multiplexer. It's really easy to implement. (more info in link above).

    Maybe Sparkfun will update this one day?

    • kresty (L3-G0) / about 10 years ago / 1

      I'm using a Lepai 2020A+ for the amp. From what I can see it already has a similar protection circuit, so I just cut the trace for the funny signal ground that's not real ground right before it enters the jack. Seems to work great (at least for me). (I made sure there were 0 ohms between the jack ground and the through hole a bit back on the trace I was gonna cut to make sure it was the right one, though it was pretty obvious).

      So, if your amp has the protection caps and stuff you might be able to do that too.

      • kresty (L3-G0) / about 10 years ago / 1

        I just realized that this wouldn't work for everyone if you had different power supplies. It works for me because L3-G0 (my Lego R2-D2) is battery powered with a common ground bus. Presumably, after cutting the trace, you could tie the ground pad pointed out in zlp's diagram above to the jack ground. You'd still have to make sure your amplifier decoupled the inputs with the caps and stuff. (Not needing it I haven't tried that, and you'd want to make sure your grounds were the same obviously).

    • Member #264047 / about 10 years ago / 1

      ZIP, can you answer a couple of questions ?

      1) Those 10 mf capacitors you show in your diagram, are they 50 volts ? 2) I am assuming the resistors are all 1/4 watt ? Am I wrong ?

      I am a low-level schematic reader. Sorry bout that.


      • zlp / about 10 years ago / 1

        You can probably use any voltage rating >= 5v for the caps. (16v would be physically smaller than 50v and totally adequate.) The resistors can be practically any wattage. (Mine are 1/4W since that's what I had, but 1/8W would be fine too.)

        Have fun. For future projects I'll use the WAV Trigger which has all the protections built-in (and adds ridiculous set of new features).

  • CTPCTP / about 12 years ago / 4

    Just wondering if anyone at Sparkfun realizes what a massive hassle it is that the analog output protection isn't designed into the board. It takes this from being hugely and immediately useful to me having to search for another possible solution.

    • Member #22245 / about 11 years ago / 1

      I just went to plug in my board again, and it no longer works. The VLSI chip is getting very hot, and current draw is 500mA! Perhaps ESD had something to do with it. Not happy. $50 down the drain.

      • kresty (L3-G0) / about 9 years ago / 1

        I have three of them and am pretty happy, but I'm having the same/similar problem, VLSI is getting really hot and not working. Anyone have a clue what happened to cause this? Static? Overvoltage? I'm using "12V" battery for the power, but that's nominal, it is of course more like 13V. Is that unsafe?

    • Member #22245 / about 11 years ago / 1

      By using the Mono Audio Amp Breakout - TPA2005D1 (BOB-11044), you won't have to worry about analog output protection.

      From the BOB-11044 product description: "The fully-differential inputs are safe for floating audio signals such as from our MP3 Shield, and can also be connected to ground-referenced signals as well."

      It's working great for me.

  • Member #650642 / about 9 years ago / 2

    I am using this with my ardunio set up to get sounds to my r2d2 , works perfect, im also using the amplifier kit from spark fun, just make sure to use a ground loop isolator to avoid any issues.

  • Member #562858 / about 10 years ago / 2

    Hi - just received the board. All the audio I play through it is of a terrible quality.. Is this something I am doing wrong? Or is it not a high quality play back device? Mp3 192kbs soudns great on everything I tested on.. just not the board. Thanks

    • Member #590879 / about 10 years ago / 1

      I am having a play quality issue as well. The playback is stuttery' as if it needs a bypass filter or something. I am using the pwrsply from my A-mega board. I'm wondering if it is a power issue?

  • Spock / about 11 years ago / 2

    Bought the MP3 trigger to make a quiz with fun buzzers (like the quiz QI has), Worked awesome and we had lots of laughs! Thanks!

  • Lark / about 12 years ago / 2

    The MP3 trigger was great for prototyping, but now I want to make a small run and $50 each is a bit much.

    Does anyone have a suggestion for a cheaper sound board?

    My requirement are: - holds 7-10 tracks (don't care what format, but I would like to load it myself). - in those 7-10 tracks it holds about 1 hour of sound. - on board 1 watt amp (a big plus)

    Thanks for any suggestions in Advance!

  • Member #733407 / about 9 years ago / 1

    Can someone give me the overall dimensions of this board? I don't see the dimensions listed on the product page. I've got a project with a small form factor and I'm wondering if this would fit. Thanks!

  • Member #69512 / about 9 years ago * / 1

    Updating Firmware via PSoC MiniProg1

    Am having issues when attempting to use the Cypress MiniProg1 to change firmware to 2.53 or to re-upload ver 2.54. Firmware updates located at

    When attempting to upload the HEX, receive the error msg "Failed! Hex File parsing failure. PSoC Programmer does not support current type of hex file."

    PSoC software version is MiniProg1 is 1.81 (latest). No problem reading CY8C29466 on the MP3 Trigger.

    Question: Since the currently shipping Triggers have a boot loader which enables the firmware to be updated via the SD card, can it no longer be performed via the MiniProg?

    • robertsonics / about 9 years ago / 1

      Correct. If you've managed to blow away your bootloader (which can only be done with a hardware programmer) then you'll need to contact SparkFun tech support.

  • kresty (L3-G0) / about 9 years ago / 1

    Stoopid question, but is this repairable? Like can I get another VLSI for it? I released the magic blue smoke... :(

  • kresty (L3-G0) / about 9 years ago / 1

    Is 12V a "hard" limit on the power supply input? I fried mine, but I'm not quite sure how, the only thing that comes to mind is that the 12V batter is, of course, a little more than 12V.

  • kresty (L3-G0) / about 9 years ago / 1

    I like the board so much for L3-G0 that we got a second one for MCK-Y. But for this application we're getting noise from the steering servo. If I pull out the MP3 trigger (and use a different source), then the noise goes away. The trigger's connected straight to the battery, and controlled by serial Arduino.

    It's clearly RF interference or maybe a ground loop or something, but it has me stumped. Any suggestions? (PS: My amp, Lepai 2020A+, has an appropriate ground loop isolation circuit on the input, it's not on that end)

  • Member #579139 / about 10 years ago * / 1

    Some music tracks go very skiperdy. So I'm dead chuffed I've got tunes coming out after trying with many shields that defeated me ( usually around library issues - arg!) but this trigger is a breeze - dead easy to 'program' using the SD card - love it! But now I have quality issues where some tracks, from my card, the MP3 just doesn't seem handle well. At busy/loud parts the output goes all jumbly-skiperdy and just sounds like it can't cope the data stream. Upon further investigation I found a correlation with the bad tracks stored in 320kbps and the good tracks are lower, usually around 240kbps. Am i barking up the right tree here? Also can anyone recommend the best SD card (TF card in American) for the Trigger? Is it possible that a better card could sort this problem out as many cards don't seem to work at all. Is FAT16 format better than FAT32?? I would very much appreciate some guidance here so I can power up a Jukebox for my dancing fountain! By the way the Sparkfun Spectrum Shield is excellent - very forgiving and reliable.

    • robertsonics / about 9 years ago * / 1

      The MP3 Trigger is really only designed to support bitrates up to stereo 192kbps. Anything beyond that taxes the PSoCs ability to fetch data from the SPI microSD interface. It's not a matter of getting a faster card, or FAT16 vs FAT32.

      If sound quality is that important, I'd suggest you look at the WAV Trigger, which in addition to playing uncompressed 44.1kHz stereo (CD quality), is also polyphonic, allowing you to play and mix up to 14 tracks simultaneously. That, and a lot more features.

  • Member #624853 / about 10 years ago / 1

    Why is there no PAUSE function? That seems like an obvious function to have, at least add it to the serial interface. Would also be nice to add the capability to start tracks at particular points, like start track 3 at 33secs.

    • robertsonics / about 10 years ago / 1

      The VLSI MP3 decoder makes both of these things difficult. The device doesn't like being starved for data, as it would if you paused in the middle of a file, and it actually reads the MP3 file header so you can't just start in the middle somewhere. Also, because MP3 audio is compressed, there's no easy way to know where 33secs is in the file without playing to it. The WAV trigger has a pause function for individual tracks (it's polyphonic, so you can pause one track while playing another), but does not yet have the ability to start at a given point other than the beginning of a track. This actually hasn't come up very often as a feature request.

      • Member #624853 / about 10 years ago * / 1

        On the VS1063 there is a PAUSE_ON mode that can be enabled and then a PAUSE bit can be set. The decoder plays what is currently buffered and then halts audio output. On the microcontroller side you stop feeding the buffer. Would it be possible to get this added to the firmware?

        On a different note, have you ever used the sidestream audio with the built in mixer? It would be nice to mix live mic audio with an MP3 playing.

  • Member #590879 / about 10 years ago / 1

    Issue: Only triggers 17 & 18 play mp3 files when brought "LOW." I have a self-test run to test that all 1-18 play before void loop() begins and again, only 17 and 18 play during the diag. I remember someone mentioning below about how 17 and 18 are wired directly to the PSoC. What am I missing here?

    • robertsonics / about 10 years ago * / 2

      Triggers 1 through 16 go through an analog multiplexer and therefore behave differently from triggers 17 and 18, which are direct GPIO pins to the PSoC. Technically, these are passive active low - meaning that grounding them activates the trigger and an open circuit is considered inactive. They're really designed to work with a contact closure to ground. I've seen cases where driving the trigger inputs to 5V prevents them from working properly. If this is the case, then switching the Arduino output between output drive low to activate and then to floating (high impedance input) to deactivate may work.

      Also, how long are you pulsing the trigger inputs?

      By the way, if you're really controlling all 18 trigger inputs from an Arduino, you may want to consider using the serial control port instead. Only 3 wires required to connect (GND, 5V and TX) and you can then start up to 255 tracks instead of 18.

      • Member #307167 / about 10 years ago / 2

        The 74HC4067 is an analog multiplexer. Referring to the data sheet shows that there are NO internal pull-up or pull-down resistors. Without pull-up resistors to 3.3V, the inputs and output float. This would cause the false-triggers or no triggers reported by some users. As 'zip' pointed out earlier, connecting a 1K pull-up to the output of the multiplexer fixes this condition. But that is only part of the story. The 1K pull-up is only connected to an input when that input is selected. This fixes the "bad-trigger" problem but still allows the unselected inputs to float into their linear region. This causes high current consumption. Some users report the regulator getting hot.

        • robertsonics / about 10 years ago * / 2

          The output of the mux is pulled up by the internal pull-up in the PSoC GPIO, just like trigger inputs 17 and 18, which also have no external pull-up and work fine. Long cables, combined with very fast switching and sampling of the mux inputs, can sometimes cause false triggers, and a stronger pull-up can help in those cases. Also, there's been a firmware update on the download page for quite awhile that increases the settling time for the mux switching that can help without the need for hardware mods.

          I'm working with SparkFun on a rev to get the external pull-up added as well as making the audio output be ground-referenced and AC coupled.

      • Member #590879 / about 10 years ago / 1

        I've written some code in the IDE to monitor ambient energy levels; over the last year I've been able to isolate over 100 or so repeating energy events using the debugging monitor.

        I want to use the trigger card to push audio notifications for when the event(s) occur and then play a computer voice that announces which event level has occured. This application is working and is announcing events using a piezo speaker and a 4 tone varied note melody unique to the event. I want to move it to the next level and have voice responses.

        I would love it if it were possible to use it serially and code it to where when environmental event 137 were to occur that 137event.mp3 could be called and played, then ending in silence until the next event occurred.

        All the example I've seen for the serial method has shown the MP3s played randomly or in order. Is it possible to uniquely call and play individual MP3s and how much of the 128k memory would allow 255 subroutines? :)

        • robertsonics / about 10 years ago * / 2

          The serial control port allows you to play or trigger 255 tracks (001xxx.mp3 to 255xxx.mp3), and the message format is in the Users Manual. But you need to be able to write the Arduino serial routines yourself - I don't have example code. You may be able to find examples if you search around. However, at the risk of sounding like a salesperson, the new WAV Trigger (same price, same size) has tons more capability, better sound quality, and more importantly, there's an Arduino Serial Control library for it. It provides up to 999 tracks and allows you to mix and crossfade. Just sayin...

          • Member #590879 / about 10 years ago / 1

            I got it working using the serial access to the 255 MP3s. Great device.

          • Member #590879 / about 10 years ago / 1

            Do you know when the WAV Trigger will be available for purchase. I tried buying it today, but there are none in stock.

    • Member #590879 / about 10 years ago / 1

      Using a Arduino 2560 to trigger and power it.

  • Member #133693 / about 10 years ago / 1

    I am trying to connect digital outputs from the Arduino Nano to the trigger inputs on this MP3 Trigger board. The MP3 Trigger seems to be working fine and I can trigger each sound using a jumper. However, the digital I/O from the Arduino Nano won't trigger the sounds. I measured the voltage on the trigger pin and it is switching from 4.85V down to 0.390V. My assumption is that is not low enough to satisfy the trigger inputs. Has anyone had this problem?

  • Member #590879 / about 10 years ago / 1

    Just got my 2nd board after thinking I might have fried the first one. I'm powering the unit with an Arduino Mega 5v and gnd. I have 18 songs loaded on the mini SD. The songs play when I move the roll switch. Everything seems to be in place for me to use one of the 18 trigger ports. Is there a way I can test each trigger individually before I hard solder them into place. Can't I just touch two of the contacts and the corresponding file plays?

    • Member #133693 / about 10 years ago / 2

      Yes, one row of pins are all ground and one row are the triggers 1-18. Just short the desired trigger pin to any of the ground pins for a brief second and you will hear your sound play. This is described in more detail in the manual.

      • Member #590879 / about 10 years ago / 1

        Been there, done that... Simple described, but simple, it does not. I've touched row 1, pin 1 to row 2 pin 1. Row 1, pin 5 to row 2 pin 5 nothing happens. I'm certain the problem is obvious once I discover it, but I'm bleeding from my eyes and ears trying to put my finger on the problem. I have the unit powered off of the 5v and gnd off of the A, Mega, mini speaker jack has a feed to a small amp. Toggling the roll switch plays the files in sequence. I've rtfm nothing becomes revealed. It s/b as simple as changing the batteries in a tv remote. Is there a wiring diagram for a hard trigger project somewhere or suggestion that I can build from to help me remove this block? I have two units and both are doing the same thing.

    • Member #590879 / about 10 years ago / 1

      After re're'rereading the user guide I discovered that I had the files named wrong. Track001 instead of 001track. My dyslexie also happens from time to time when working with compound letter groups. Perseverance pays, I can sometimes be a pitbull when it comes to letting go of problems or issues. -LOVE the technology!

  • Member #597180 / about 10 years ago / 1

    I'm a novice building a push button triggered mp3 audio unit that will be mounted in a interactive box that will be traveling nationally with a fine art exhibition. The signal coming out of the 1/8" jack is too hot for listening on regular headphones. Is there any way to lower the outgoing signal to a listenable level without building two triggers for up and down volume? Ultimately, I'd like the unit to have a set volume that is lower and not mess with the volume control or buy a pair of headphones in which we could control volume. I've tried to lower the dB of the mp3 tracks, but that doesn't seem to help. Any suggestions would be helpful

  • Member #544133 / about 10 years ago / 1

    I have two of these and I am trying to use a simple headphone splitter on each to connect two sets of headphones to each unit. One of the units seems to be working fine. The other has a static noise coming out even when there is no audio playing. The noise is not present when I only use one set of headphones, only when I have both headphones plugged in to the splitter.

    • robertsonics / about 10 years ago / 1

      No idea. Do you have two splitters and four headphones, and does the problem follow one of the splitters or one of the headphones?

  • Al.Acoustic / about 10 years ago / 1

    I have got my first MP3 Trigger and played around with it for a bit! It is awesome and exactly the kind of kit that I wanted to complete my prototype project that is to work in Sub-Zero environment with Sound and Audio systems. I will be installing the MP3 Trigger along with other system components that I have developed in an IP Rated enclosure next week at site that consistently maintains with -4-degrees C throughout the year!

    I will post an update later on how the unit performed. Best regards,

    • Al.Acoustic / about 10 years ago / 1

      Just completed the prototype and all works just great. Superb product! what I like the most is the capability to reprogram the trigs using Text file.

  • Member #565734 / about 10 years ago / 1


    I am using a AT42QT1070 breakout board to trigger the Mp3 Trigger with capacitive touch buttons. Firmware is v 2.54 and the cables betweeg the AT42QT1070 and the trigger inputs are less then 3 inch, so the long cable/false trigger problem should not be an issue altogether.

    However, when I trigger input 1 and keep the trigger going (button pressed/touched) the Mp3 Trigger responds as if input 1 and 5 are triggered alternatingly although the AT42QT1070 breakout does not indicate triggering of the button attached to five. Similarly, if I keep on triggering 2 the Mp3 Triggers receives 2, 6, 2, 6 etc.

    Anybody any idea what is going on? :-)

    Thanks a lot Thomas

    • robertsonics / about 10 years ago / 1

      I assume if you instead hook up an simple contact closure instead of the capacitive button, it works properly?

      The MP3 Trigger really wants to see contact closures - triggers grounded for active and either floating or high impedance when not active - because of the input multiplexer. I suspect your capacitive touch driver outputs 5V when not being touched. You could try using triggers 17 and 18, which are direct inputs to the PSoC.

      Not that this helps, but unless you absolutely need MP3 playback, I'd recommend the WAV Trigger since it supports all manner of input trigger interfaces.

      • Member #565734 / about 10 years ago / 1

        Hi Jamie, thanks for the answer. In the meanwhile I tested the Mp3 Trigger without the AT42QT1070 by just triggering with a simple contact closure as you said and this gives the same problem, plus I tested a second copy of the Mp3 trigger with the AT42QT1070 and that works fine. So I suspect there is some issue with the logic of my first Mp3 Trigger copy. BTW, pins 17 and 18 indeed are fine so maybe a faulty multiplexer? I wrote that the low trigger pins x also trigger alternatingly x+4, the pins with x+4 > 16 trigger alternatingly x - 4 so something funny is going on. Thanks Thomas

        • robertsonics / about 10 years ago / 1

          Given your description, I'd suspect a bad solder job on the S2 address input to the multiplexer. Have a look under a magnifier at the S0 - S3 pins of both the mux and the PSoC.

  • Member #520153 / about 10 years ago / 1

    Does anyone have a problem with the voltage regulator (LD1117)? Mine gets extremely hot almost instantly when I use a 12v wall wart.

    • robertsonics / about 10 years ago / 1

      While the input specs for the LM1117 regulator state an input voltage range up to 15V, I recommend keeping it to 9V or less for this very reason. Personally, I try to use 6V whenever possible for both the MP3 Trigger and the WAV Trigger. This is especially important for the WAV Trigger because it includes an on-board audio amp which, when enabled, can consume substantially more current.

  • Sayde / about 10 years ago / 1

    do you have service to mexico?

  • Member #469781 / about 10 years ago / 1

    Sequencing... first let me say this is a great item, I been doing up to 16-announcements with this unit, is there an easy way to sequence up to 22 spiels with one button? This will be on a train, as the train goes around the park the operator press the button at a marked location for the spiel about the attraction, the spiels runs 7~20-seconds, stop & wait for the operator to press the button at the next location, etc, etc. My question is how to do this easily with 1-button.... Thank you for your time & help....

    • robertsonics / about 10 years ago / 1

      Yes, you can do this. Using the init file, set the desired trigger function to "Next" and enable the restart lockout feature for that trigger. Do a quick format of your microSD card and make sure to copy the tracks to the card in the order that you wish them to play. The "Next" trigger function plays the tracks sequentially in the order that they appear on the card, not by their file names.

  • Member #531786 / about 10 years ago / 1

    Does someone know how long it takes from the trigger signal to the start of the sound?

  • dhauck / about 10 years ago / 1

    Where are the pullup resistors for the inputs?? With no pullup resistors, how does the line go back to a logic 1 after you've removed the trigger (short to ground)?? Such a great idea but so poorly done. I will definitely be more careful to check schematics before I order anything else.

    I assume this is the cause of random triggers and crosstalk. Unless I'm missing something?

    • robertsonics / about 10 years ago * / 1

      Pull-ups are internal to the PSoC GPIO inputs - refer to the drive options in the PSoC data manual. The most common cause of random triggers is the analog multiplexer and the increased capacitance of long wires when the mux switches inputs. Increasing the pull-up strength by adding a 1K pull-up resistor on the output of the mux allows for longer wires on those trigger inputs. Triggers 17 and 18 don't go through the mux and therefore don't exhibit this behavior.

  • Member #491360 / about 11 years ago / 1

    I recently purchased this board and everything worked fine for a week or so. Today, when I use it, I get nothing. When I power it on, I get the red power light but no green status light? Any Ideas?

  • Member #496855 / about 11 years ago / 1

    The latest firmware is supposed to enable pin 18 to be a play status output. The new Robertsonics website says "See sample initialization file below for documentation on the volume and play status output functions" but the said file (as far as I can tell) makes no mention of the play status output function. Just so happens, thats the bit I need. I remember seeing it on the old site. Can you help?

  • I was going to say, grab the Personal Soundtrack Shirt off ThinkGeek and tear it down, but they don't carry that anymore. Oh well, I can put a wireless (IR, BT, etc) control on this one. :-)

  • Member #383017 / about 11 years ago / 1

    Weird characteristic... This board powers itself from the Rx line if power is removed from the USB-VCC pin.

    Even if R19, a 10K pullup is removed, a signal from a Yún (Yun) D{#) out (used via software-serial library) is enough to power up and maintain CY8C29466 as "ON"

    Any suggestions welcomed. I would like to be able to turn this completely OFF simply by removing power from the USB-VCC pin (5V).

  • Member #492001 / about 11 years ago / 1

    I've got a constant slow blinking status light, which the manual says shows a decoder hardware problem, but this is all the info I can find... is the trigger totally fried if this happens?

  • Member #435752 / about 11 years ago / 1

    I want to power a PIR and transistor circuit using the MP3 trigger power supply so that I only need one power supply. Is this safe? Will I fry anything? I plan on hooking up to dc socket and ground on the board.

    Here is the PIR:

    and here is the transistor:


  • Member #14422 / about 11 years ago / 1

    Hmm, I see that the serial interface is 3.3-5V, but looking at the schematic it runs @ 3v3, so I ASSSUME that the input is 5V tolerant...but the output would never get upto 5V ? Is this correct ?

  • Member #412616 / about 11 years ago / 1

    I have reviewed the user manual and have updated the firmware. I have included a MP3TRIGR.INI file with "#BAUD 9600" but the MP3 trigger won't operate at 9600 and stays at the default 38.4K for when I use serial communication. Help?

    • robertsonics / about 11 years ago / 1

      Please email your ini file to: info(at)robertsonics(dot)com. I'll take a look.

  • agemoz / about 11 years ago / 1

    I love this device! What a great improvement over the winbond voicerecorder chip I had been using for messages on my home automation intercom. Very quiet (intercom is on all the time, imperceptable noise), and doorbell sounds beautiful! I use the serial interface to trigger all kinds of home status messages, and believe it or not, I am likely to run out of messages at the 255 limit. Is there any possibility of an extended serial command that could expand the number of messages? Thanks again--easy to use and very well done.

  • Jason.C / about 11 years ago / 1

    If I hook the MP3 trigger up to this amp - - would I need to build a line-output protector or would a ground-loop isolator do the job to keep it safe?

  • Member #412616 / about 11 years ago / 1

    I have a 8GB mirco-SDHC card that works just fine with the nav switch and all, but I need to control what audio track using serial communications. So I found a 2GB micro-SD card, loaded the latest firmware, held down the center nav switch while power up, released and got rapid blinking. I don't understand how it works otherwise but when I update is showing hardware error status. Please help me understand how I can get my mp3 trigger working for serial communication.

    • robertsonics / about 11 years ago / 1

      Serial communications is supported by all versions of firmware to date, so you don't necessarily need to update your firmware. In any event, it sounds like you may not be renaming the firmware hex file to "mp3trigr.hex" on the SD card that you're trying to load from.

  • Member #134554 / about 11 years ago / 1

    I use my mp3 trigger to play recorded samples at intro's, like the cash register intro on Pink Floyd's Money. I have 3 triggers set to play tracks 1 to 3, then I have about 120 other songs on the card to play on breaks. Problem 1: No matter what I set the RAND setting, I still get track two playing in the random play set of songs. Problem 2: I can't get the list of random mp3s to play consistently. I have a switch rigged to input 4 and have it set as random play. When I flip the switch, sometimes it plays, sometimes it doesn't, and sometimes it starts playing in the middle of a random mp3. Problem 3: I have a momentary switch wired to input 18 and have it programmed as a stop. If random switch (input 4) is on, sometimes pressing the stop button will start a song, sometimes not. When it does, same problems as Problem 2.

    • robertsonics / about 11 years ago * / 1

      Regarding Problem 1, it would help if I could see your init file. You can email me directly at info(at)robertsonics(dot)com. For Problem 2, are any of your trigger wires particularly long - like more than 2 feet? If so, you can try moving the random switch to Trigger 17 which doesn't go through the multiplexer, or you can add a pullup resistor to the mux. Zip's post above shows how to do this. Regarding Problem 3, I think may be a use case I hadn't considered. You mean you want to leave the random trigger active with a switch, but stop with another trigger? How would you start the random function again?

      • Member #134554 / about 11 years ago / 1

        I will send you the ini file later today. My wires are about 6 inches long. I use my random switch as follows. I'll turn it on and leave it on through our band breaks to play the music randomly. If there is a song that comes on that I would like to skip, I press the stop button. When I release the stop button (my play switch is still on) it generally starts up another random song, but not always... as oulined in the original message. Also, with no interaction, just leaving the random switch on, sometimes after a track finishes, i will get nothing, as if it has stopped. If I press the stop button, it may start playing tracks again and sometimes I have to turn the switch off and on again.

  • Member #473156 / about 11 years ago / 1

    Love this card! I'm having good luck with it playing individual tracks at specified volume levels (quiet mode only so far). Quick question: By "quick real-time volume control" do you mean that you can modulate the volume of a given track during playback? (as opposed to setting the volume and waiting for the track to end). I would like to be able to increase/decrease the volume in real-time during playback..... Is this possible?

    • robertsonics / about 11 years ago / 1

      Yes! This is, in fact, the main reason I designed the thing, since I couldn't find any other product that allowed smooth, real-time volume control. The serial Set Volume command works immediately, even while a track is playing. Keep in mind that in order to produce smooth volume ramping, you will need to send small changes often. Write your code so that it doesn't send the Set Volume command unless you want to change the volume, and then send small changes as often as every 20 msecs until you get to the target volume.

  • MikerK / about 11 years ago / 1

    Please fix link to Firmware Updates. Thanks

    • MikerK / about 11 years ago / 1

      Disregard previous request: I just spotted the support link provided by Robertsonics.

  • Member #340857 / about 11 years ago / 1

    Just learning serial communication with this product. I am operating the board with a PIC16F84A and using picbasic. Could I get an example of a serout command to trigger track 020blasterbolt.MP3 I can operate the single Nav commands serially just fine. It's the two byte commands I just can't get to work. Thanks for any help!

    BTW, Thanks for the mods zlp, they work great!

  • Member #461684 / about 11 years ago / 1

    Can any of you gurus help me with a project? I'd like to rig this up to play a sound when my car door is opened. I know where the power wires are for the door triggers and can tap into that.

  • Member #134554 / about 11 years ago / 1

    I bought this thing about a year ago for experimentation and never got around to using it. I want to update the firmware but the page keeps showing an internal server error. I need to know the revision history to see if my unit (dated 10-2-1) will take the new firmware. Anybody have comments?

    • robertsonics / about 11 years ago * / 1

      Sorry about that. I've been working on my website over the last week. Try this: support

      As long as you have a V2 with 18 trigger inputs, you can update your firmware. Keep in mind that while the firmware can play MP3 files from any microSD card, the bootloader can only read firmware updates from SDHC (2GB or less) cards formatted as FAT16.

      • Member #134554 / about 11 years ago / 1

        Will my unit have the ability reprogram the triggers as the current manual states? BTW, thanks for your prompt answer!

  • Member #459498 / about 11 years ago / 1

    Planning to have 2 or more of these MP3 boards go at it at once, summing the audio outputs together into one output and sending that to an separate amplifier. What would be the most effective (and safest) way to sum the outputs without killing any of the MP3 boards? Thank you in advance.

    • MikeGrusin / about 11 years ago / 1

      Take a look at the datasheet for our Class-D Mono Amp; it has notes on page 13 on how to sum two differential inputs together (which is what comes out of the MP3 Trigger). One set of resistors (150K) is already on the board, so you'll have to add an extra pair of resistors for your second input, but you can make use of the through-hole resistor pads on the board to get the signal directly to the amplifier chip. This is a mono amp, so you'd need two of them to do stereo if that's a requirement.

      You could also add the protection circuit to both outputs which will make them ground-referenced, and run them into any external amp. Good luck with your project!

  • Member #459498 / about 11 years ago / 1

    Would like to place BCD data (5-bit) strobed from a separate microcomputer into the trigger pins. Will I need a BCD to binary decoder? If so, what can be recommended in this case? Thanks!

  • Member #20773 / about 11 years ago / 1

    Just received my trigger (batch #35942). I dropped a couple of mp3 tracks on a 4GB SanDisk micro SDHC card formatted FAT32. On powerup I got the quick flashes indicating it found media and mp3 files, but it wouldn't play. The status LED responded to stop/start and fwd/prev switches, but no audio out. I reformatted the card FAT16, dropped the same files on it, and it works perfectly. Not a big deal, but I was surprised. If old firmware was the issue, I'd hope current batches were shipping with current firmware.

    I needed to make up a prototype to get feedback from a customer about what sound effects worked best for him. This little card was perfect for that one-off application. Later I hope to hack the 1063 code for some programmable effects like pitch and tempo alteration. Looks like there's lots of code on the VLSI web site.

    Thanks for a nice little device!

  • Member #439025 / about 11 years ago / 1

    Hello! I just came across this product site and wonder if it will meet our needs. As part of a museum exhibit, we would like to have an older Bell-style telephone on a desk that visitors will pick up to hear a recorded message. There will be 8-10 messages and I would like playback to start from a different message each time the phone is picked up. Would the MP3 trigger work for this application? Also, would the audio output be enough to drive a speaker in a phone handset?

  • Kevin_S / about 11 years ago / 1

    Just wondering how easy this would be to integrate it with a toy piano. I guess, first select the mp3 file to play, but not yet play it until a piano key is pressed, however having the pitch of the playback sound change depending on which key was pressed to simulate different pitches or notes on the scale. I could pre-record various instruments and nature sounds or even my voice and play them back using a cheap toy piano. Thanks.

    • robertsonics / about 10 years ago / 1

      Check out the new WAV Trigger, which is polyphonic. The demo video actually shows how to make a toy piano.

    • M-Short / about 10 years ago / 1

      Because you can only play one track at a time I wouldn't use this, but take a look at the Music Instrument shield, it might be better for that application.

  • Member #404483 / about 11 years ago / 1

    I have some serious issues on this product. Most of the times I start it up it won't play my files! Then I need to restart it then it works. We've put 5 of these in one of our products. When we start it up, it won't work immediately. Everything is connected right. Some trigger inputs are connected so they play immediately when it get's power, others are triggered by pushbuttons. But even then it won't work. I changed the power supply unit so it works fully solo, even then it won't work. We changed them for others, no results! We checked the files and change them, no result! We got to deliver within 2 weeks, anyone for a solution?

    • Member #336086 / about 11 years ago / 1

      I have the same problem. We have 20 units in a museum exhibition and randomly some of them won't start. When turning off the power and reconnect it they start and play again. They have the newest firmware. Changing SD card and power supply doesn't help

      • robertsonics / about 11 years ago * / 1

        Did you try firmware version 2.40 beta that I mentioned just above? (It's not the most recent version.) There was an earlier issue that I tracked down with some VS-1053 decoders not resetting properly on power up, and this release specifically addressed this. If you're having the same issue, I would expect 2.40 beta to at least make some difference. Is it always the same units? You can also email me directly at info(at)robertsonics(dot)com.

    • robertsonics / about 11 years ago / 1

      Please go here and try firmware version 2.40 beta as an experiment to see if this affects your startup issue.

  • fridata / about 11 years ago / 1

    It seems like nobody knows that there is a splendid library for Arduino:

    I tried it, works great. I even implemented the Quiet Mode for the library. Wick mentions it in the comments for the product page of the old board model WIG-09715.

    Also, I used it for my project Arduino Sample Player with Volumes:

    This has since been expanded with support for 16 banks of samples, so it can play 255 different samples, all with separate volumes defined.

  • Member #382493 / about 11 years ago / 1

    I am confused about this analog output protection.

    Is a small portable battery / USB powered speaker safe to use with this MP3 trigger? Technically, it amplifies sound, but I wouldn't call it a traditional amplifier per se.

    • Member #22245 / about 11 years ago * / 1

      If you want an amplifier to drive a small speaker, SparkFun part BOB-11044 (Mono Audio Amp Breakout - TPA2005D1) will do. It can deliver 1.4W into 8 Ohms.

      You won't have to worry about analog output protection, as it has differential inputs.

      It's working great for me.

  • toyotaboy / about 11 years ago / 1

    I'm trying to use this for a pinball project. I can hook up one of the 18 inputs to a target (leaf switch), hit it while the machine is off and works fine. As soon as the pinball boots (5 second delay), the sound starts activating over and over. Wondering why power coming through the ground would cause the mp3 trigger to activate? Do I need a diode to isolate the trigger from the AC power?

  • Member #387310 / about 11 years ago / 1

    Is it normal for the VLSI chip to feel warm to the touch while operating?

  • So can I just throw on your 0.5 Watt 8 ohm speaker you sell and have it work? Or do I need an amp and some protection?

    • Member #22245 / about 11 years ago * / 1

      If you want an amplifier to drive a small (eg. 0.5W 8 Ohm) speaker, SparkFun part BOB-11044 (Mono Audio Amp Breakout - TPA2005D1) will do. It can deliver 1.4W into 8 Ohms.

      You won't have to worry about analog output protection, as it has differential inputs.

      It's working great for me.

    • If you want to hook this up to an amp, you will want to look at the line out protection information posted above. We have had customers user this with the 8 ohm speaker, but it's not very loud, so in all likelihood, you will want to include an amp (and therefore, line out protection).

  • bromine / about 12 years ago / 1

    Once an mp3 file is triggered, will activation of a trigger interrupt the existing track?

    Based on what I've read in the comments and the manual, I can't tell if the next mp3 will start only after the current one ends, or if it will stop the current playing one and immediately play the next trigger song.

    Can you clarify? Thanks!

    • robertsonics / about 12 years ago / 1

      Normal operation is that a trigger will interrupt any track that is currently playing by starting the new track immediately. However, through the ini file, each trigger can be individually programmed to be "locked out" while audio is playing. So the answer is "both".

  • Member #380926 / about 12 years ago / 1

    Hi, i am new in electronics and wondering if this board could run with battery or any other portable power supply. if so, how?

    there is a product called 9V Battery Holder by sparkfun. can i use it with the mp3trigger board?

    thanks for your help! okan

    • Kamiquasi / about 12 years ago * / 1

      Yes, you can run this with a portable power supply such as a battery, as long as the voltage output of that battery is between the "4.5-12VDC" specified.

      A 9V battery will work, but keep in mind that an Alkaline 9V battery is maybe 600mAh at best. The given current draw is " Current Consumption: 45mA idle, 85mA playing". 600mAh divided by 85mA is approximately 7 hours of use - at best.

      4 AA batteries (Alkaline 6V, 8800mAh, 4 days+ OR rechargeable NiMH 4.8V, 2600mAh, 5 days+) would considerably lengthen the time you can use it without having to replace/recharge batteries.

      As far as hooking things up goes, this board has a 5.5mm/2.1mm center positive barrel jack. So if you did go for SFE's 9V battery holder, the 9V battery clip, or 4xAA battery holder that all have a 5.5mm/2.1mm plug, you would just insert that and off you go.

      If you went with a battery holder that doesn't have that plug, such as 4xAA battery holder, no plug, perhaps to save space, then you will have to solder some wires. If you look at the barrel jack on the board, you'll notice that it is soldered to 4 pads on the board. The pad closest to the "3.3V / VBUS" solder bridge selector is the positive terminal being used - you would solder the positive/red lead of a battery holder to that pad. The two pads on the other side (next to the "USB / EXT" text) is the negative side. You would solder the negative/black lea of a battery holder to either of those two pads.

      For what it's worth, I would go with the 4 AA battery holder myself if weight isn't too much of a concern. It is almost the same size as this board, which means that with some creative hole-drilling and sunk bolts you can actually mount this board straight to the battery holder.

      Good luck!

  • Member #367246 / about 12 years ago / 1

    Anyone knows how long does the firmware update takes? I tried it but the light kept blinking for almost an hour. I have the hex file on the card, press the nav switch down, power it up and let it run for what I understand the light should go solid at some point. I'm I doing this wrong?

    • Member #367246 / about 12 years ago / 1

      So found out that I was using a SDHC card which apparently is not compatible. Changed to a regular sd card FAT16 but still doesn't work. Anybody??

  • Member #372961 / about 12 years ago / 1

    Does anyone know does this play the left and right channel of audio. I am trying to use one mp3 trigger with our rfid door locks to say a message in two different rooms. I was going to have a small amp connected to the left channel and the same for the right channel. would this idea work?

    • Member #380926 / about 12 years ago / 1

      using an audio editing software, you can prepare two stereo files which are hardly panned

  • Member #367246 / about 12 years ago / 1

    It seems like in most projects arduino is used to drive the mp3 trigger. Anyone knows how to do it with a pic18f4550 or is it too complex?

    • MikeGrusin / about 12 years ago / 1

      The MP3 Trigger supports an easy to use set of serial commands (see the datasheet up top). If you can send simple data out your PIC's serial port, you can control the Trigger.

      • Member #367246 / about 12 years ago / 1

        Do you know of info out there that could serve me as a guide?

        • MikeGrusin / about 12 years ago / 1

          From the MP3 Trigger end, the user manual above (sorry, I said datasheet earlier) lists all the commands, which are simple letters and data bytes like "F" for forward.

          In terms of getting your PIC18 to transmit those characters through its serial port, how you do that will depend on what you're already using to program it. Most people use MPLAB and either Microchip C18 or another vendor's C language. There should be full examples in the documentation for your programming package and on the internet for sending text characters (search for "PIC18 serial" or similar). Good luck!

          • Member #367246 / about 12 years ago / 1

            Thanks for your help. I think I have a pretty good idea now.

  • Member #280813 / about 12 years ago / 1

    Hi, Will im still unclear - will a simple ground loop isolator solve the Output Protection Problems??

    Any Help is much appreciated! Thanks, Jon

    • Member #22245 / about 11 years ago / 1

      If you want an amplifier to drive a small (eg. 0.5W 8 Ohm) speaker, SparkFun part BOB-11044 (Mono Audio Amp Breakout - TPA2005D1) will do. It can deliver 1.4W into 8 Ohms.

      You won't have to worry about analog output protection, as it has differential inputs.

      It's working great for me.

  • Member #216992 / about 12 years ago / 1

    MP3 Trigger, WHY YOU SO EXPENSIVE???

  • Member #367246 / about 12 years ago / 1

    Anyone knows if there are eagle files for the mp3 trigger as a whole?

    • Not sure what you mean by this. The eagle files are up in the documents section.

      • Member #367246 / about 12 years ago / 1

        I understand that the eagle files of the mp3 trigger are available, however I am looking for a file that displays just the inputs and outputs of the trigger without "the insides". I'm working on a project that would have the trigger connected to a pic microcontroller, and I was wondering if there is a "mp3 trigger" part available somewhere. Thanks for your help.

        • Yea, we don't have an image like that ready, but you could easily make one in Fritzing or open the files in eagle and modify the .brd file to your liking.

  • Member #147077 / about 12 years ago * / 1

    Command from the USART, can not be added or pause? I want to be able to answer questions in Japanese. Do not have staff that can speak Japanese?Call me.SkypeID:zeatec

  • Member #360483 / about 12 years ago / 1

    newbie question - I cannot play files using the triggers. I've followed the makerjam troubleshooting guide, updated the firmware and have the spoken number files on the card in the format "TRACK001.mp3" (extensions not hidden). The navigation wheel will play all the files. As I understand it, if I close the contacts at Trig1 (ie. connect the trigger pins) I should trigger the file "TRACK001.mp3". Have i missed something?

    • Member #360483 / about 12 years ago / 1

      Yep, I missed this. "After v2.40, the only requirement is that the first 3 characters of the filename are "nnn", so that "001audio.mp3" is perfectly valid. But this means that the old style names no longer work."

      • Sorry about that! The naming convention change has tripped up a lot of customers with the new versions. Hopefully that fixed your trigger issue though. Let us know if you run into any more problems.

  • vs / about 12 years ago / 1

    Got this thing to work fine with headphones but I cannot seem to make it work with a simple external 12W audio amp ! I am using a KEMO 12W mono amplifier from I get the audio, but tons of hum. I even get hum when no audio is playing. Any ideas ? I am an audio dud. Also, do I need to worry about anlog output protection ? I am using WIG-11029 and the amplifier is on the same 12 volt power supply.

    • Bob_NJ / about 12 years ago / 1

      The audio output of mp3trigger works well with isolated loads (like a headset). It can be troublesome when trying to use it with an amplifier, or any other device with a single-ended input referenced to power supply ground. The reason is that both the left and right outputs as well as the return line at the mp3trigger headphone connector all have a DC bias. You will need to build an isolation filter (a 1 micro-farad non-polarized capacitor is OK) in series with the right and left outputs as well as the return line. Note that the return connection of the mp3trigger is not the same as the power supply ground. More details on this issue can be found at the forum.

  • andycomic / about 12 years ago / 1

    I used this board to demo various routines for my robot:

  • raydzek / about 12 years ago / 1

    What is the ETA for back orders? Or if this is EOL what is the replacement? Thanks!

    • This board is not EOL, so no replacement at the moment. It looks like it may be a bit longer before we can get these all built up and shipped out. Sorry for the delay.

  • Member #341932 / about 12 years ago / 1

    The board works great! Thank you. How do I prevent a sound file associated with a pin # from re-triggering if the pin is held low? I am using a main power switch to turn pin #9 low to play "System activated" but it loops and repeats message. How do I have it not replay even though the signal is held low? Thank you

  • Member #336086 / about 12 years ago / 1

    I'll ask again: Is there any risk in using this product with a mono headset, where left and right channels are bridged together, to make a mono sound out of the stereo output? Or, in other words, to put a mono (two-pole male 1/8") plug in the stereo output (which bridges left and right signal)? Can this damage the device? Thanks in advance! Please answer, I need to know soon. Thanks!

  • If you are a beginner, DO NOT BUY THIS! This thing is so temperamental. It takes a genius to connect this to an Arduino. Then it dies. What a waste of $60.

    • If you are having problems with your board, please email us at techsupport at sparkfun dot com. We would like to help you out if possible!

  • scienceguylabs / about 12 years ago / 1

    Can I use these toggles ( as the trigger switches for each mp3?

    • Yes, you can. You simply need enough triggers for however many tracks you want to be able to play.

  • Member #336086 / about 12 years ago / 1

    Is there any risk in using this product with a mono headset, where left and right channels are bridged together, to make a mono sound out of the stereo output? Or, in other words, to put a mono (two-pole male 1/8") plug in the stereo output (which bridges left and right signal)? Can this damage the device? Thanks in advance!

  • Can anyone advise if this would make sound on a 8 Ohm, .25W speaker? Or do I need an Amp?

  • Majones / about 12 years ago / 1

    I intend to mount my mp3 trigger in an antique crank-operated phone that has a big, beautiful magneto dynamo in it which actuates a solenoid to ring the phone's bells. I'm assuming that this'll put the mp3 trigger at risk for all kinds of induced-current-related shenanigans. The mp3 trigger will be mounted below the magneto, and a trigger line and the audio output will run up the body of the phone, past the magneto.

    From my research thus far I'm thinking build the esd protection diode array from the app notes, a ferrous metal cage that wraps around both sides of the board to divert magnetic fields, and perhaps shielding on the trigger and audio lines. Overkill/Underkill? Any thoughts would be greatly appreciated.

  • Daka / about 12 years ago / 1


    I'm unable to get tracks to play via triggers using the file name standard in the User Guide.

    I have done the following: 1. Confirmed that MP3 files play just fine by pressing the navigation switch. 2. Tried naming the files properly according to the User Guide: i.e., "001 ocean waves.mp3" for the file that should play when input 1 is triggered, "002 Ship Sounds.mp3" for the file that should play when input 2 is triggered, etc. These files don't play when triggered. 3. Read the troubleshooting guide at Took a look at the "Spoken Number Test Files" and saw that their names are different than those in the user guide. Changed mine to match: i.e., "TRACK001.mp3" for TRIG01, etc. and this works.
    4. Thought maybe I had a filename length problem, and so tried "001ocean.mp3", "002ship.mp3". These do not play. Even just "001.mp3" doesn't play. The only thing that works is "TRACK001.mp3", etc.

    I'm wondering if I've got a card with old firmware or something. I'd rather know for certain before proceeding to update it, if possible.

    Thanks for any suggestions!

    • robertsonics / about 12 years ago / 1

      It definitely sounds like you have older firmware. If this is a unit you received just recently from SparkFun, please let them know about it through customer service. In any event, I'd suggest updating the firmware using the links above.

      • Daka / about 12 years ago / 1

        Thanks for your feedback. I tried updating the firmware, and all appeared to be fine during the process (i.e., I saw the flash steadily for a while, and then turn solid, just as the "Using the boot-loader" section of the User Guide indicates it should).

        Now, however, after re-booting it I no longer get the 3 quick flashes of the status LED: now I get 1 long blink (indicating no formatted microSD card media found). I tried re-loading the firmware 3 times, and the same thing happens every time.

        (By the way, I am using the same MicroSD card with the same MP3 files as was being read previously, and also it is the same one that seems to be getting read fine for the firmware upgrade.)

        I'd appreciate any new suggestions...


  • blake31 / about 12 years ago / 1

    is it possible to play one track as a background loop and then have the other tracks triggered on top of the background track without interrupting the background track?

    • robertsonics / about 12 years ago / 1

      Yes, but not without interrupting the background track. The MP3 Trigger can only play one MP3 stream at a time. The use of the VS-1053 decoder precludes mixing multiple tracks.

      • blake31 / about 12 years ago / 1

        so, it would stop the background track, and then I'd have to re-trigger the background track again? so to do want I want to do, I'd need two of these? one to play the background track in a continuous loop, and another to play various tracks while the background track plays uninterrupted. (think pinball machine, where I want background music playing, and then sound effects when the ball hits certain targets)

        • robertsonics / about 12 years ago * / 1

          You would not need to re-trigger the background track if you just jumper it - it would restart automatically as soon as the foreground track stopped. However, in order to have two sounds playing at the same time, you would need two units. Mixing MP3 tracks is not possible with this design.

  • Member #325120 / about 12 years ago / 1

    if i have 12 buttons and i want 1 song per button, this is the right thing to buy?

  • rossflight / about 12 years ago / 1

    Is it possible to connect triggers to the next / previous and play / pause controls instead of using the jog wheel?

    • robertsonics / about 12 years ago / 1

      Yes. Using the init file, you can repurpose any of the trigger inputs to be start/stop, next or previous functions. See the init file example above for details.

      Note that the MP3 Trigger does not support pause. Tracks always start at the beginning.

  • Member #304107 / about 12 years ago / 1

    Hooked it up today and plays well, except that the volume setting is not stored for next power up. Am I missing something?

  • PeterG / about 12 years ago / 1

    So I've been looking at the VLSI app note about the analog outputs, and I'm concerned about the GBUF pin being tied to the sleeve of the 3.5mm jack on this board.

    For my application, I intend to drive a pair of amplified PC speakers rather than headphones. In this case, I think a ground-loop condition will occur which could kill the VS1063. I'm guessing I should cut the trace that connects the GBUF pin to the sleeve of the jack, and wire the sleeve to ground instead.

    Can you confirm whether this is correct or not?

    • MikeGrusin / about 12 years ago / 1

      You're correct - don't plug it in to an amplifier that connects signal ground to power ground. You can cut the trace, or build an adapter circuit into your cable, but either way you should implement the circuit in figure 8 of the above app note. R7-R9 and C3-C5 are already on the MP3 Trigger board. C1 and C2 are unspecified, but 1 to 10uF should work well.

      • Member #83790 / about 12 years ago * / 1

        Mike: you forgot R8 is also already on the board. R7,R8,R9,C3,C4 and C5 are already installed. Cut the trace is a good solution. But like you said is better implement circuit below for both audio outputs R and L. ______10uF____100 Ohms_______Ins | Outs ---10K------mp3 trigger ground

        • Member #83790 / about 12 years ago / 1

          The ground can be the connection where the RX and TX (FTDI) are located (GND) or one of the trigger pins on the left row.

  • RyanTM / about 12 years ago / 1


    I have a 16Gb Micro SDHC card with a FAT32 file system on it. It came with my cellphone. I followed the instructions to load songs onto it. I put it in the MP3 trigger and it did not play when triggered. I tried a 1Gb Micro SD card and that worked fine (same file, same procedure). Is a 16Gb card supposed to work? I would expect up to 32Gb to work if the MP3 Trigger supports SDHC fully.


    • robertsonics / about 12 years ago / 1

      Very likely you have older firmware that doesn'tt support FAT32 or cards larger than 2GB. You can update your firmware (using your 1GB card) and then be able to play MP3 files from the FAT32 cards. See the second post above.

  • Member #12264 / about 12 years ago / 1

    I am still having trouble understanding what I need to do to protect the output of the mp3 trigger. From page 6 of the VS10XX AppNote: Connecting analog outputs "A ground loop can happen for example with a VS10XX application that uses GBUF and has USB or Ethernet connected and the output of VS10XX is connected to a PC souncard. Figure 6 illustrates this situation." so if I don't have USB or Ethernet connected than am I alright to operate? My setup is going to be an mp3 trigger powered by an external power supply connected to an amplifier thanks

    • Member #83790 / about 12 years ago / 1

      You can try an "audio isolation transformer". They have that in Radio Shack. I'm not 100% sure if will protect the mp3 trigger but may be Robertsonic can help you to find out.

      • Member #12264 / about 12 years ago / 1

        Thank you for the info. My application will use a smaller amp with an 1/8th" input and everything sounds great. #83790 I appreciate you taking the time to share your input.

    • Member #83790 / about 12 years ago / 1

      The problem with connecting to a big amplifier is that doesn't have ESD protection. You will find that protection usually in devices like a receiver or a mixer with mp3 input (line level). You can build a circuit with a diode connected to ground. There is also something you can buy in radio shack that may work, I don't remember the name right now... let me search...

  • Member #83790 / about 12 years ago / 1

    So the Mp3 trigger will not support baud rates of 9600? really? so whats the purposes of "quiet mode" if I can't use it?

    • robertsonics / about 12 years ago / 1

      As suggested, please have a look at the User Manual in the link above. In addition to describing the serial command protocol, including Quite Mode, there is a section on an optional initialization file, with which you can set the serial port baud rate to a number of different values, including 9600. All are 8 bit, 1 start, 1 stop, no parity.

      • Member #83790 / about 12 years ago / 1

        The basic stamp works at 7 bit. will not work, is that right?

        • MikeGrusin / about 12 years ago * / 1

          I haven't used the BS2 in 10 years, but a bit of googling shows that yes, you can set the BS2 to 8 bits, 1 start, 1 stop, no parity, and 38400 baud. I saw notes saying it might drop characters at 38400, but since you're only sending and receiving a few characters at a time, it may work fine. Finally, as Robert said, you can change the MP3 Trigger to use 9600 via the initialization file. So there are several ways in which you should be able to make it all work. Dig into your BS2 docs and give it a try!

    • MikeGrusin / about 12 years ago / 1

      Why can't you make your BS2 run at 38400?

      • Member #83790 / about 12 years ago / 1

        Yes, you are correct. I think the problem is the BASIC Stamp can communicate at 7 data bits, 1 stop bit or 8 data, no parity, and 1 stop bit. The manual of mp3 trigger sayd 8 data bits. What do you think?

  • Member #83790 / about 12 years ago / 1

    Robertsonic please answer my question!!! How can I use the BS2 (parallax) to enter the mp3 trigger into Quiet Mode? and detect wich trigger was activated? SEROUT .....? SERIN......? Graztie!

    • MikeGrusin / about 12 years ago / 1

      The User Manual (there's a link to it following the product description above) has a whole section on the serial control protocol, including what data you need to send, and what data it will send to you. For example, quiet mode is entered by sending "Q1".

  • rmeyer / about 12 years ago / 1

    Wow did I miss something? We can now program the pins on these for volume control? I have been trying to find workarounds for this for a long time. Is it possible to upgrade the firmware on the older boards for this function?

    • robertsonics / about 12 years ago / 1

      Yes. By using an optional initialization file, you can program any trigger input to be either volume up or volume down, among other things. And yes, any MP3 Trigger V2 can be upgraded with the new firmware. See the second post above. Hope this helps.

      • Member #443739 / about 11 years ago / 1

        Is there a way to change how much the volume increases or decreases when using the trigger with an initialization file? It seems I've only got two levels of volume to go between and it would be awesome if I could have a bunch more! This is a rockin' product, by the way, thank you!

  • hamcake / about 12 years ago / 1

    Will a strip of header pins fit for the trigger inputs?

    • robertsonics / about 12 years ago / 1

      Yes - it's just a 2 by 18 standard header. I use break-away dual row strips, but 2 single row strips will work just as well.

  • DMKitsch / about 12 years ago / 1

    looking at the VLSI Application Note for protecting analog outputs, it is not meant to be followed for the VS1063 is it?

  • EliTheIceMan / about 12 years ago / 1

    Considering the output is line level, what could you connect that does not require the analog protection? Seems like this should be integrated.

    • EliTheIceMan / about 12 years ago / 1

      I looked over the app note but since I am in need of analog volume control would a pair of unity gain opamps at the output do the trick?

  • robertsonics / about 12 years ago * / 1

    All of the new features are in the product description above, just not itemized as new per se. In addition to FAT32 SDHC card support, better support for 192kbps MP3 files and a more flexible file naming system, there's an optional initialization file with which you can set the serial port baud rate, and more importantly, enable useful new alternate functions on individual trigger inputs, like random and sequential triggers as well as volume controls.

    Both the User Guide and example initialization file in the links above have some formatting issues that I am trying to get corrected ASAP. In the meantime, you can find all the documentation on the new features here.

    For those of you with VS-1053 V2 boards, you can update to the V2.50 firmware here. Just keep in mind that your bootloader does not support SDHC FAT32 microSD cards, so while you will be able to use those cards for MP3 playback (normal operation) you'll need to keep at least one SDSC FAT16 card around for future firmware updates.

    • Member #77979 / about 12 years ago / 3

      Is there an example code to control/play mp3 files in the SD card using serial communication?

  • NetMeyer / about 12 years ago / 1

    As this is a replacement product, is there a means to list or link, the relevant enhancements? Is there more than SDHC support?

Customer Reviews

4.4 out of 5

Based on 9 ratings:

Currently viewing all customer reviews.

3 of 3 found this helpful:

MP3 Trigger

used this with the spark fun amplifier kit for my full size r2 unit, sounds great, thanks

Fine device.

I use the MP3 Trigger in a product called, "Digital Toy Counter". It is a device that allows a theater organist to activate various fun sounds such as train whistle, rain and thunder, etc. The original theater organ toy counter was a bunch of sound-making devices attached to a wind way. Devices such as agooga horn, cymbal, drum, etc. That is why it was called a Toy Counter, a countertop where all the toy sounds were located. I sell it through

MP3 Trigger- "The Best'

I use this product to play safety announcements at theme parks & go Kart tracks in our own DSA-4M self contain system. This MP3 Trigger is the heart of our system. Not only sound great, but works great also. We use this unit as trigger, as a sequencer, sequence with a timer, & run off solar power when needed. If a trigger MP3 player is needed, this is the one to get, this is a great product. Thank You Sparkfun....

Awesome product!

I used this to add custom audio to a pinball machine. Set up was very quick & easy. You'll need to provide your own dc power supply, micro sd & pre amp. Works flawlessly!

Good POC product

This product brings joy to my kid and a lot of peoples. Easy to set it up.

Randomness factor could be improved. Should allow organizing mp3 files into folders Should allow total random selection of mp3 files across folders.

Works as advertised

It works as advertised, documentation on the product is very poor. You just need to figure things out on your own.

Hi, Did you see the user guide? It's a pretty solid document in helping get started -

Works as they said

Not sure why they had the skills-required rated as high as they did.. I just added a push button and changed one line of code in a pre-made config file they provided, seems pretty simple to me. I like it!

OK, so now that we are trying to use it "for real" and more often, there seems to be a problem. I have a push-button switch on one of the triggers; when pushed it should sound a random one of the five songs on the card. Some of the time this works. At other times, all that happens is a very short flash of the green status light. Is anyone else encountering this?

Not bad, more support and documentation is needed

This product did what it was supposed to do. I tried to get help with writing the INIT file on the forum, but I have not been able to get any help.

Works great

I am using the MP3 trigger to provide music for a miniature carousel. It works great, and gives us a convenient way of selecting which music to play. It was easy to set up, and the default settings are just fine for our uses.