I've been using open source software for about two decades and started getting interested in open source hardware three years ago. To be honest, it wasn't until about four years ago, after implementing a school authority's back-end infrastructure (everything but the desktops) nearly entirely using open source software that I was fully sold on it.
But I was still questioning the value of open hardware. That has only recently changed. One big factor for the change in my thinking is that Arduino clones became available for practically nothing (about $2.50US for a Pro Mini). Similarly, modules to do just about anything are now available for a pittance. A motivated person can now get the bits to prototype a product with a very small outlay. Of course, they need the know-how to put it all together and write the software. And that's where OpenEnergyMonitor comes in.
I've been building an Arduino based thermostat. It is still just a toy, and actually started on a Raspberry Pi, but has evolved from a graphing thermometer to an Arduino base-station which controls a relay that triggers the furnace and an Arduino-based battery powered temperature monitoring module. The base-station and monitoring module communicate via nrf24l01+ transceivers (a poor-man's RFM12B/RFM69CW). I wanted to bring the Raspberry Pi back into the project to implement a flexible web-interface for configuring and monitoring of the heating system.
That's the back story.
My problem was that there doesn't seem to be a useable radio communication library for the nrf24l01+ with implementations on both the Raspberry Pi and the Arduino. There is a fork of the RF24 library with Pi support, but I found RF24 unsatisfactory, especially after using the RadioHead library.
So I asked myself: What does OpenEnergyMonitor do to support the RFM12B on both the Arduino and the Pi? A bit of hunting through some Building Blocks and I had my answer: It uses a microcontroller to bridge the Pi and the radio module. Brilliant! I had thought about doing exactly that, but that was back when Arduinos where more expensive. Now that they are cheap, this is very doable.
My thanks to Glyn, Trystan, Martin, and Robin, specifically for sharing their work, more generally for helping jaded folk like myself see the benefit of sharing solutions to problems.
Re: Open Energy Monitor solution for radio support: Smart.
On behalf of all those mentioned, and a few more besides - thank you!
Re: Open Energy Monitor solution for radio support: Smart.
Hear hear - very smart bunch of people on here, who are extremely generous with their time and expertise. A big thanks from downunder as well - loving my OEM system and the monitoring goodness it provides.