I know! The Pi3 isn’t exactly expensive for what it can do but a Pi Zero with on-board WiFi for a little over a tenner. plus a cheap case, plus a rfm69pi and emonSD, you have an emonbase for under £50 including PSU etc, it would just about do a full emoncms server, but it would easily make a modern “Rock Solid Gateway” for forwarding data to another server, self-hosted or emoncms.org.
I would like to explore whether we can get 4ct’s and a RFM base running on an emonTx, If we can I would like to try @Robert.Wall’s unitless CM lib with a close coupled connection between the Pi and the Tx so the Pi can do all the calibration and phase correction calculations whilst the Tx focuses on just continuous sampling and RFM reception.
The Pi can handle multiple pulse counters which the emonTx(due to limited interrupts) and emonPi (due to no easy access to the gpio) cannot. One of these would allow easy “plug’n’play” connection of up to 4 optical pulse counters or temp sensors. I’ve already done separate Python scripts for 2 optical pulse counters and for 18x ds18b20’s so if we can get emonHub rolling again these new interfacers wouldn’t be hard to implement at all.