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Retired Product

This is a retired product. There is an updated version available: DEV-13736

Creative Commons images are CC BY 2.0

Description: Replacement:DEV-12646. The Teensy has been update to v3.1! Now with more RAM, flash memory, 5V tolerance on digital inputs, and more! Go check it out. This page is for reference only.

The Teensy is a breadboard-friendly development board with loads of features in a, well, teensy package. The Teensy 3.0 brings a 32 bit ARM Cortex microprocessor into the mix so you can do some serious number crunching.

The Teensy 3.0 comes pre-flashed with a bootloader so you can program it using the on-board USB connection: No external programmer needed! You can program for the Teensy in your favorite program editor using C or you can install the Teensyduino add-on for the Arduino IDE and write Arduino sketches for Teensy!

The processor on the Teensy also has access to the USB and can emulate any kind of USB device you need it to be, making it great for USB-MIDI and other HID projects. The 32 bit processor brings a few other features to the table as well, such as multiple channels of Direct Memory Access, several high-resolution ADCs and even an I2S digital audio interface! There are also 4 separate interval timers plus a delay timer! Oh yeah, and all pins have interrupt capability. Also, it can provide system voltage of 3.3V to other devices at up to 100mA.

All of this functionality is jammed into a 1.4 x 0.7 inch board with all headers on a 0.1" grid so you can slap in on a breadboard and get to work! Do keep in mind that the Teensy 3.0 is a 3.3V system, which makes it compatible with a lot of sensors that utilize 3.3V signalling but can run you into trouble if you’re used to 5V dev boards.

Note: This does not come with a USB cable, please check below for an appropriate one.

Dimensions: 1.4 x 0.7" (~35 x 18 mm)


  • 32 bit ARM Cortex-M4 48 MHz CPU (M4 = DSP extensions)
  • 128K Flash Memory, 16K RAM, 2K EEPROM
  • 14 High Resolution Analog Inputs (13 bits usable, 16 bit hardware)
  • 34 Digital I/O Pins (10 shared with analog)
  • 10 PWM outputs
  • 7 Timers for intervals/delays, separate from PWM
  • USB with dedicated DMA memory transfers
  • 3 UARTs (serial ports)
  • SPI, I2C, I2S, IR modulator
  • I2S (for high quality audio interface)
  • Real Time Clock (with user-added 32.768 crystal and battery)
  • 4 general purpose DMA channels (separate from USB)
  • Touch Sensor Inputs


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Customer Comments

  • This is amazing! I feel like I’ve been in the dark by not knowing about these!

  • This product description should highlight PROMINENTLY that the connector is micro-B, not mini-B as other Teensy products use. Even the Teensy site graphics show mini-B; you have to notice exception text for the Teensy 3.0. While I have a landfill worth of mini-B units, I’ll have to make a second order for the micro-B cable.

  • Nice! I would love to see an audio-output for this! :-) SparkFun? Anyone? Anyone? ;-)

    • An audio shield is being designed. If you’d like to chime in with any input, or just follow the development, here’s the page where it’s being discussed.


  • The loader appears to be proprietary, and I’ve had trouble getting it working under Ubuntu. (Not to mention the creepiness of downloading binaries blindly from uncontrolled sources.)

    • I’ve had no issues running on Ubuntu 12.04 LTE following the setup at pjrc.com. In fact it seems faster to upload than when running on a much more powerful Win7-64 notebook. IMO the Teensy loader utility is no more or less creepy than other Linux binaries. Overall I find the Teensy bootloaders (I have used them with Teensy2, Teensy++2, and Teensy3) work way more reliably and are faster than the official Arduino boards. Paul has done a better job of USB support, IMO.

  • So the Arduino IDE plug-in; that must be a sizable plug-in; compiler plus the syntax management and all. Anyone using the Arduino IDE plug-in? How does it feel? Though an Arm processor it is still a true real time code execution, correct? No Linux touchy feely timing stuff like the Pi?

    • The Teensyduino download is 22 megabytes for the Windows version, 30 megs for Mac, 24 megs for Linux. (full disclaimer: I’m the author of Teensyduino!) Those sizes are for version 1.13. Like all software, the size will likely change over time as more capabilities are added.

      Teensy runs very similarly to regular Arduino boards. Your code runs directly on the hardware with true real time access, just like Arduino… except the ARM processor is faster than AVR and your code is 32 bits, so using “byte” and “long” are the same speed. All the normal functions like digitalRead, pinMode, analogRead, analogWrite, pulseIn are supported. Many of the widely used Arduino libraries are supported (and numerous others also work). Here’s the official library list for Teensyduino:


      Teensy does NOT run Linux like Raspberry Pi. If you give it a try, you’ll discover it works very much like Arduino. Probably the biggest difference you’ll notice is the Upload process is much faster!

      • I tried it myself, and I must say it’s impressive and way faster with uploads than the Arduino. Definitely the best option if you want something powerful, small, and easy to use. Oh, and cheap! under $20!!!

  • does the MK20DX128VLH5 have a (single precision) floating point core? i’m having a hard time finding any info online…

  • I know i know - “We do not currently have an estimate of when this product will be back in stock.” But do you - by any chance - know IF this product will be back on stock. I know I can get it at PJRC store but i want to order some other products from SparkFun. And since I’m not from US splitting orders on two separate suppliers is a bit on the costly side. Teensies in EU are expensive - 25€. I need 6 of them.

    • They won’t be. We are waiting on the 3.1 to come into stock, and we will be selling those. They should be coming soon though.

  • “Do keep in mind that the Teensy 3.0 is a 3.3V system, which makes it compatible with a lot of sensors that utilize 3.3V signalling but can run you into trouble if you’re used to 5V dev boards.”

    Wait, does that mean that it can only run off of 3.3 Volts? Is there a voltage regulator or no? If no, that means that I cannot run it off of a 12V battery with a separate 5V voltage regulator, like I can with a Teensy 2.0, right?

  • If you’re debating whether or not to branch out from Arduino into a different board, you owe it to yourself to give Teensy a try. It’s an easy transition with a lot of programming space, speed, and inputs/outputs in a, well, teensy package. I’ve had to make nearly no changes to existing Arduino libraries to make this work with my existing code.


  • How much current can this guy handle per pin and overall? Its probably in the datasheet, but I can’t find it and that thing is over 1200 pages.

  • This Sucks! couldn’t make Windows 8, 7, or even XP work more than Once whit the USB-Driver…. found my self fixing windows driver auto detection every on every reboot, what a waste of time.

  • I couldn’t get the SD library from Arduino or the SdFat library to work very well. The SD library worked once, and is extremely spotty. Any suggestions on how I can get this to run smoother?

    • Hi, Paul here from PJRC. I’m concerned about this problem. If you see this reply, please post a message on the PJRC Tech Support Forum with the details.


      To investigate this problem, I really need you to post the complete Arduino sketch which reproduces this problem. I’m currently working on Teensyduino 1.16. The SD and SdFat libraries are a priority. If this isn’t easily resolved, after 1.16 releases I’ll dig into the SD / SdFat code if necessary. But I need you to give me a starting point that reproduces the problem.

  • Just a note, DON’T USE the SPARKFUN 32K CRYSTAL for this board! It is way too big! Check out the ‘Using the RTC’ link above to see the recommended crystals. Sparkfun, any possibility of stocking the smaller crystals?

  • Does anyone know if you can store data from a sensor in the on board flash memory and then retrieve when you connect to a computer via usb.

    • Per the maker, not at this time, although you can do this with the Teensy2.0++


  • Shouldn’t this board as well as the Due be listed under the ARM section? Might help people compare capabilities more readily.

  • Love the Teensy! It’s an awesome board. I’ve used dozens of them in projects. :)

  • Description says “You can program the Teensy in your favorite IDE using C…”. Has this been verified, and if so, on what non-Arduino IDE?

    • For using it with “your favorite IDE”, there are a few 3rd party projects targeting the most popular environments. Hopefully one of these is your favorite?

      If you prefer Eclipse, Jantje’s Arduino Eclipse plugin supports Teensy. Here’s some links:

      . http://www.baeyens.it/eclipse/Install.html

      . http://forum.pjrc.com/threads/1474-Anyone-using-Eclipse-for-development

      If you love Xcode (Mac only), the embedXcode plugin supports Teensy.

      . http://embedxcode.weebly.com/

      . http://embedxcode.weebly.com/download.html

      . http://forum.pjrc.com/threads/169-embedXcode-Teensy-3-0-on-Xcode

      If Visual Studio (Windows only) is your game, the Visual Micro plugin recently added support for Teensy 3.0. Here’s the link:

      . http://visualmicro.com/page/Teensy-for-Microsoft-Visual-Studio.aspx

      If you’re a command line minimalist who only gets slowed down by any GUI, a good makefile is probably all you need. After you install Teensyduino into Arduino, the sample makefile is in hardware/teensy/cores/teensy3/makefile (on a Mac, control-click Arduino, choose “Show Package Contents” and dig down a few folders to find “hardware”). The makefile has comments with advice about which directories from Arduino you need to save, and which parts you can delete.

      All 3 of the IDE plugins are third party projects. They’re separate projects from Teensy. If you use them heavily, please show them some support.

      • Thanks. I’m an analog engineer trying to improve my programming and was concerned about getting bogged down in tool issues. I’ve been using TI CCSv5 with the Launchpad kit, so I’ll probably investigate the Eclipse option.

      • Thanks for sharing all of this!

    • Yup, it uses gcc and you can program it in plain C or C++. You just need to install the arm-gcc binaries, it is easiest to just download the teensiduino then use the binaries directly out of it even if you don’t use the arduino IDE. I program msp430, teensy 3.0, and avr/arduino boards all using vim and it works great.

    • I should have said your favorite “Program Editor”

      When it comes to building your code, you’ll need to be able to compile for the proper target depending on what version of the Teensy you have. Download the Teensyduino package, which will come with everything you need in that regard, it includes the arm and avr toolchains as of the latest version. Also the example makefile with comments on how to get rid of the parts you don’t need for standalone use outside of Arduino.

      To load your code onto the board, use their Teensy Loader utility.

  • Great to see that you have brought this board into your shop :-)

    I just stumbled upon a tiny typo in the description though: “beings a few other features to the table as well” I guess it should be: “brings a few other features to the table as well”

  • Finally you guys carry Pauls boards, these are awesome!

  • This is a very nice board, I have two of them (although not obtained via SF). It is as easy to use as the less-powerful ATmega-based Arduino boards, and super small as well. If you’re buying one of these, you should probably check out the support forum on PJRC, it is active and questions are addressed quickly.

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