EmonTx v2





A low power wireless energy monitoring node. It's designed to sense data from multiple CT current sensors, optically from a pulse-output utility meter and from multiple one-wire temperature sensors. It can be powered by 2 x AA batteries or 5V USB.  Features and hardware details.

The emonTx is based on the Atmega328 8-bit micro-controller and is fully compatible with Arduino IDE. A 5V FTDI to USB cable is required for programming.

´╗┐The design is based on the JeeNode. It's fully open-source and is designed for easy expandability and compatibility with JeeLabs plug-shields.

Thank you to Robert Wall for the port map diagram.


See dedicated features page

Build Guides

Open Hardware

The emonTx is open hardware with the designs released under the Creative Commons Attribution-ShareAlike 3.0 Unported License. The schematics and board files can be viewed and downloaded from the openenergymonitor github hardware repository here:

Firmware Examples

Start by setting up the Arduino programming environment so that your all ready to upload code once you have build the board: Setup the Arduino Programming environment

All emonTx V2 Arduino Firmware is available on github here, see readme for list of available firmware's: