SparkFun LoRaSerial Kit - 915MHz (Enclosed)

The SparkFun LoRaSerial Kit is a pair of serial radio modems that simply passes serial back and forth between one another. The LoRaSerial provides you with the means to report data every few seconds even if it's located beyond WiFi or Bluetooth® range. With this kit, you'll be able to transmit data over LoRa giving it incredible range compared to other methods. We’ve even been able to regularly transmit over a 9mi (15km) line-of-sight using two LoRaSerial radios using a larger 5.8dBi antenna on the transmitter and the stock 1/2 wave dipole antenna on the receiver.

LoRaSerial utilizes a 1 Watt, 915MHz transceiver and an open-source protocol to transmit AES-encrypted data at 4800bps or approximately 480 bytes per second. Although this won't get you video streaming quality, the LoRaSerial is very good at getting whatever data you need, encrypted or not, from point A to point B without fuss. The radios in this kit automatically frequency hop (FHSS) between channels to avoid collisions. The ‘airspeed’ or data rate is configurable up to approximately 2,000 bytes per second for shorter range, or for extremely long range transmissions, as low as 40 bytes per second.

The radios in the LoRaSerial Kit support simple point-to-point communication as well as multipoint broadcasts. Multipoint broadcasting makes this kit ideal for GNSS RTK and many other geospatial scenarios where one device needs to produce and delineate data that many other devices might need to utilize.

The LoRaSerial firmware supports an innovative and simple-to-use ‘training’ method. Pressing the train button on both radios will generate a new random network ID and AES encryption key to share them. This makes pairing radios in the field as simple as a press of a button. By bringing the radios near each other the LoRaSerial training method is as simple and secure as you could ask for.

Currently, SparkFun is offering radios in the LoRaSerial Kit that utilize 915MHz modems that are allowed in most parts of the world. Please check your local restrictions before purchasing. The radios are fully configurable to restrict frequencies, channels, dwell time, power output, and a variety of other settings to make the radios compatible with your local regulations.

Note: LoRaSerial is designed to operate at the physical layer of LoRa sending data directly to an endpoint as opposed to something like LoRaWAN which operates on the data and network layers. For this reason, LoRaSerial is not intended to operate on LoRaWAN.

  • 2x Enclosed LoRaSerial Radios with 915MHz, 1W LoRa Module
  • 2x 915MHz 1/2 Wave 2dBi Antennas
  • 2x Serial Interface Cables
  • 1x USB A to C Cable
  • 1 Watt (30dBm) power output
  • LoRa SX1276 Based
  • 915MHz unlicensed band radio with 902-928MHz configurable output
  • 256-bit AES GCM encryption
  • AT command set
  • Built-in Frequency Hopping Spread Spectrum (FHSS) technology
  • Point-To-Point and Multipoint configurations
  • 3D Printed Enclosure (May darken over time)
  • Configurable air speeds from 400 bps (40 bytes per second) to 19200bps (1920 bytes per second)
  • Configurable standard serial data rates from 2400 to 115200bps
  • 4-LED RSSI Indicator
  • 3.3 to 5V operation
  • USB-C connection available for industrial systems and single-board computers (SBCs like Raspberry Pi)
  • 6-pin JST connector available for embedded systems (5V and 3.3V tolerant I/O) with flow control
  • Small footprint, lightweight, easily mountable
  • Open source Software and Hardware

SparkFun LoRaSerial Kit - 915MHz (Enclosed) Product Help and Resources


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 #1823472 / about 3 months ago / 1

    I'm trying to maximize my range to 4km, however the supplied antennas only achieve around 750m in LOS for low latency. What is the best DBi antenna to achieve low latency and stable connection around 4km?

  • Member #1841348 / about 4 months ago / 1

    How can I connect these antennas to the RTK Facet using what cable, what distance can be obtained and what is the difference between serial lora and the teletry radio.

    • How can I connect these antennas to the RTK Facet using what cable

      The cable included with the RTK Facet is designed to directly plug and play with these radios (or the telemetry radios).

      what distance can be obtained

      Depends on your surroundings. These will not transmit through hills or large natural objects (aka rocks). Buildings, etc degrade the distance. In general open air, you can get a few miles. In an urban setting, it's a few blocks.

      what is the difference between serial lora and the teletry radio

      The LoRaSerial is built for maximum range, where as the telemetry radios are optimized for greater data bandwidth.

  • Member #1794729 / about 8 months ago / 1

    How many channels (e.g., separately paired radio pairs) can be operated simultaneously in the same area (e.g., within the 9mile reach these radios have) ?

    • Dozens, perhaps hundreds. I've had 32 operating simultaneously without a noticeable degradation but they were all transmitting dozes of bytes, not hundreds (ie not full bandwidth). It depends on how the radios are configured and how much data is being pushed through them. Very few use cases require 100% of the bandwidth of the system so this allows collisions and re-transmissions. If say two un-paired/un-known radios happen to transmit on the same frequency, likely that 400ms portion of the packet will become corrupt. The receiving radio(s) will note the corruption and fail to transmit an ACK. The transmitter will then re-transmit the packet at which time it will have moved significantly through its hop table moving to channels that are open and available to get the packet through.

      Now say you have 50 pairs of radios all transmitting at 100% bandwidth. No doubt it will be very hard to get data through, but you can do things like reduce your min/max freq by half a channel to force all the freq in the hop table to be 1/4 of a channel away from the 50 blasting radios. My math is likely wrong here, but the point is that you can slice and dice the 902 to 928MHz spectrum in a multitude of ways to allow a number of radios to coexist.

  • Member #1833844 / about 11 months ago * / 1

    I'm trying to get an arduino to output serial to a loraseral transmitting to another loraserial unit plugged into a computer, but the data coming over appears to be complete garbage, where the bytes aren't anywhere near right, and I can't discern a pattern. Is there a configuration setting that I'm missing? example: the character '1' becomes 0xFA on the other end

    Update: I'm not sure why, but a bit after reseting to factory settings, it seemed to unscramble itself after a flashing pattern of the blue red and yellow LEDs. Is there any explanation for why it did this? It seems hard to predict when this happens. I'd like to set the serial baudrate to 115200, but it doesn't seem possible to do that given that it keeps scrambling itself

    • Check that the baud rate set in the radio matches the baud rate of your sketch. A discrepancy will cause this sort of behavior. The default for the radios is 57600 bps.

  • Member #1732298 / last year / 1

    These radios, are compatible with rtk facet?? Thanks for the answer

  • I'm using a pair of these radios in P2P mode USB connected to two Raspberry Pis. (Well, okay, one of them is an Orange Pi.) I had a lot better luck with them after installing the latest FW image on both of them, and also using an Anker powered USB 3.0 hub on each end. The hubs alone didn't fix the issue I had (which I had originally thought was the radio pulling too much power from the USB port, a problem with the Pis). The issue was the device, at either end, kept disconnecting from the USB bus, and also occasionally causing the Raspberry Pi to reset. Using a Total Phase Beagle 12 USB tool to look at either end didn't yield anything useful, for me anyway. (I'm playing with these radios in the same room, so your mileage may vary.)

  • Member #1828320 / last year / 1

    Hello. Are you going to produce this kit again or everything is stopped? I can't find it anyware .... Thanks.

  • smaj100 / about a year ago / 1

    How do these connect to arduino or esp32?

    • The included cable plugs into the UART connector. An Arduino or ESP32 can then send and receive data to the radio.

  • Member #859567 / about a year ago / 1

    What are the pin out for the UART serial cable? Is there a corresponding part number?

    • I may be confused, but two UART cables are included. The UART connector pinout can be seen both on the sticker on the outside of the enclosure and the PCB silkscreen seen here.

      The pinout is as follows:

      • PWR - 3.3-5V
      • RX - Receive (Input into LoRaSerial)
      • TX - Transmit (Output from LoRaSerial)
      • CTS - Clear To Send (Input into LoRaSerial)
      • RTS - Ready To Send (Output from LoRaSerial)
      • GND - Ground

  • Member #147343 / about a year ago / 1

    I'm not seeing what kind of power I might need for these... for example what kind of solar/battery setup might be required to send some sensor data once a minute. Thanks.

    • It's here under the Hardware Overview. The average standby current at 30db transmit power is ~60mA. It depends on how much data you're sending. Assuming ~20 bytes, at airspeed 4800, this is 480 bytes per sec, or about 20ms of transmit time. Let's round up to a second because there's ACKs and possible retransmits. For 59 seconds you'll be at ~60mA. For 1 second you'll be at 510mA, or an average of 67.5mA. Using a 2000mAhr battery, you'll get 2000 / 67.5 = ~30 hours. I presume from here you can calculate your solar and batt needs.

  • Member #133922 / about a year ago / 1

    What type of range does it get without direct line of sight?

    • That is the million dollar question and nearly impossible to answer without actually setting up the radios at your location. In short, in an urban area, 1000s of feet (more than 0.3km) but likely less than a mile. But there are many factors that will improve the range:

      • Mounting the antennas high - the higher you can get away from the ground and obstructions, the better. The SparkFun antennas is on top our building. I know not everyone can do this, but laying the antenna on the ground, or behind brick walls, or near metal studs or pipes, makes things worse.
      • Avoid the earth. Getting RF through buildings is hard. Getting RF through hills or mountains is a show stopper.
      • Turn down the airspeed. By default the radios are setup for airspeed 4800 which is ~400 bytes per second. For every halving of the airspeed, you effectively double your range. I.e., 2400 is twice as far as 4800, 1200 is twice as far as 2400, etc. Note: This increases your power budget because you are transmitted for twice the amount of time.
      • Get a larger, directional antenna. Again, not everyone can mount a big antenna on the top of their house, but you rarely see small antennas on city RF infrastructure. The kit comes with good 1/2 wave 2dBi antennas. You'll need high gain antennas and potentially directional antenna (such as a Yagi) to maximize RF transmission and reception.

      Hope this helps!

  • Member #161230 / about a year ago / 1

    Hello SparkFun friends

    Can you please provide a part number for the “ 2x Serial Interface Cables” I would consider a buying a few extra for backup if I change the microcontroller it’s connected to.


Customer Reviews

5 out of 5

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So far works as advertised

I hate it when vendors press for a review a couple weeks after I buy something that I need to build into my project. So far I've tested this at short range, from one side of my yard to the other, and it works as expected. Eventually I'll be using this at much longer range. I have no reason to expect it won't work.