A Minimalistic LoRaWAN Sensor Node

The ATTNode (short for ATTiny Node) is a minimalistic node for the LoraWAN Network. It is based on the widely available ATTiny MCU from Atmel/Microchip and the HopeRF RFM95W LoRa Wireless Module. It can be used with a variety of sensors, the provided firmware does support the I²C-sensors SHT21 and BME280 for measuring climate data (Temperature/Humidity/Atmospheric Pressure) and is meant to be used with The Things Network as backend. The node can last for several months using only a CR2032 button cell sending values from the above mentioned sensors every 10 minutes.

ATTNode v1 and v2
ATTNode v2 with BME280
ATTNode v2 Case
ATTNode v3 Prototype


  • Small Size, only 47x36mm (v1) / 34x26mm (v2) / 37.5x30.5 (v3)
  • Based on widely available Atmel ATTiny84(v1,v2) / ATTiny3216(v3) MCU and RFM95W LoRa-module
  • Free GPIO-Pins from the ATTiny + Power to connect sensors on a 2.54mm pitch header
  • Firmware support for SHT21/BME280 Climate Sensors, Brightness Measurement, Alarm Trigger and Beacon Mode
  • Optional on-board LED for status signaling
  • Powered by a single CR2032 lithium battery
  • Long battery runtime using the ATTinys deep sleep mode
  • Integrated 6-Pin programming header
  • Small component count
  • Possibility for edge-mount SMA connector or u.fl SMD connector (v2/v3)
  • Open Hardware and Software, KiCad Project for the PCB, Firmware and Case Designs can be found in the git repository

Downloads for Gerber- and STL-files as well as the BoM and assembly hints can be found at the subsites for the corresponding ATTNode Version.

The current versions are ATTNode v2.0 and ATTNode v3.0

Recent Posts

TinyLoRa v2 Prototype Tests Successfull

My tests with the v2 prototype PCBs where successfull, I did not find any functional issues with the boards, and only some minor cosmetic issues. Documentation of the TinyLoRa v2 PCB is now available on this site . You can also find a ZIP with the Gerberfiles attached there, so you can order your own from the usual PCB prototyping companies.

TinyLoRa v2 First Prototype PCBs Arrived

After a long wait due to coronavirus outbreaks in China and resulting delays in the PCB production it is finally here, The first prototype of the TinyLoRa v2 Board: The triple use footprint for u.fl, SMA and wire antenna seems to work as intended, and the rest of the board works as before. So all in all a sucessfull first prototype run.

TinyLoRa v2 Combo Antenna Port

Some more development on the TinyLoRa v2 board. I have modified the SMA connector footprint in such way, that it should now be possible to also use a U.FL Connector or use a Wire- or Coil Antenna instead of the SMA edgemount connector. With this change it should be possible to use all of the most common types of antennas with the node. I also did some more cleanup and finishing touches:

TinyLoRa v2 Development started

Here is a sneak peek at the next iteration of the TinyLoRa PCBs. I got it down to roughly half the size compared to the v1 board by making it a two sided board and putting the battery holder, which is by far the biggest component, onto the Backside. I also added the possibility to use a edge-mounted SMA connector for the antenna. Because of the battery at the back the sensors don’t fit there anymore, so the GPIO-connector was flipped by 180° so the sensor now mounts over the front of the board.