Meet the emonTx

At OpenEnergyMonitor labs we have been working on designing a unit that makes building an open-source energy monitor easier. We wanted a unit that is cheap enough for a small home monitoring system yet powerful enough for a large system. We also wanted it to be easy to install and small enough to look pretty!

Two months ago Trystan announced a software milestone with the release of emoncms. Today marks another milestone for us, a hardware milestone with the release of emonTx.

emonTx stands for Energy-Monitoring-Transmitter. It's a small wireless energy monitoring node designed to take inputs from multiple CT sensors, optically from a pulse-output utility meter and from multiple one-wire temperature sensors. It is designed to be powered by 2x AA batteries or 5V USB.

  • Electricity consumption monitoring  
  • Renewable generation monitoring 
  • Heatpump monitoring 
  • Water and gas monitoring (from pulse output meter) 
  • Temperature monitoring 
  • Large scale monitoring - up to 26 emonTxs can potentially transmit to a single base station

emonTx PCB with bare minimum of components
for single channel CT monitoring

The unit has been designed to fit nicely in a case

Sneak peak inside 

emonTx is based on the Atmega328 and is fully compatible with Arduino IDE.   
The design is based on the JeeNodeV5 design, is fully open-source and is designed for easy expandability and compatability with JeeLabs shields.
The firmware is still in development, so far we have an emonTx monitoring a single CT channel and transmitting the data to a base station (Nanode + RFM12 breakout) where it is posted online to emoncms. We hope to release a beta version of the firmware in the next few weeks. 
For more information see the emonTx documentation page
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