Power monitoring appliance

[KevinKadow]

The old "Recon Sentinel" hardware (Rock64 1GB) still shows up on Amazon and elsewhere at around $20, contains a Rock64 host and 16x2 LCD display. I picked one up this week, and CPU has sufficient power to run both rtl_tcp and rtlamr. Only downside is this model has just Ethernet and USB, no onboard WiFi. Since the receiver can see multiple meters, this does require a one-time setup task to tell it what meter to report, but after that it just runs.

I use the command "rtlamr -msgtype=scm+-filterid=00000000" to watch for and decode my own meter, then display the kWh on the LCD (for the latter, see sample code in recon-sentinel-hacking). Added on a PoE 5v supply to so it can get power+Ethernet over one cable.

The script used shows the latest 5 minute interval reading if it is recent, but if the TransmitTimeOffset is high, it falls back to showing the average over the last hour instead, and if no reading in 20 minutes, it displays "No Signal" instead.

Kevin