EmonPi- a Raspberry Pi-based energy meter

We have all wanted to branch into energy monitoring at some point. Here’s an energy meter which allows you to do so. It also gives you the freedom to use the same meter as a PV solar meter or even in heating controlling at home.The emonPi is an open hardware energy meter which is based on the Raspberry Pi. The setup is made really easy with the help of community input. The unit is enclosed in an aluminium enclosure which makes it recyclable.

The applications of emonPi include home energy monitoring, heat pump monitoring and temperature and humidity monitoring. The most basic application is home energy monitoring in which the emonPi can monitor up to two single phase circuits (AC). This is done with the help of current sensors. You can customize your emonPi by adding an optical pulse counting sensor for interfacing with utility meters.

For the solar PV monitoring, more accurate Real Power along with current detection can be obtained by using two clip-on current sensors and an AC-AC plug-in power adaptor. An AC waveform sample is created using this method. In this way, solar PV generation and grid import/export can be monitored with the help of emonPi.

If you want to use your emonPi as an environmental monitor, you can do so by simply adding temperature sensors. Connect the sensors directly using RJ45 and voila, you have your own temperature and humidity monitoring system!

The Arduino energy monitoring shield forms the base of the emonPi. The energy monitoring ADC sampling is done by ATmega328. The Raspberry Pi is connected to the emonPi via GPIOs. EmonPi passes data to the Raspberry Pi using its GPIO internal serial port.The software is fully open source. The links are available in the maker’s blog. You can also buy the materials you require on their blog.

The real time data is updated on Emoncms which is an open source web app designed by the creators. The web app can be run locally on your emonPi or even on your own server. So here is a way you can build your energy monitoring system using open source hardware, a Raspberry Pi and a few sensors. So go ahead, build it and flaunt it!