I have dug out a RFM69PI I bought a while ago (which I’m sure worked) and put it into a new Raspberry Pi 2. I have written a small program to read the serial port and all is good.
I can send the “v” command and I get back:
[RF12demo.12] E i5 g0 @ 433 MHz
So my guess was no signal, so I turned my EmonTx off and on again, and it looked good, LED on for 10 sec, blink for 10 sec then flash every 10 sec. Just to verify I tried using a RTL-SDR (with rtl_433 -s 2500000 -R 45), which gave:
time : 2019-07-16 18:30:34
model : emonTx-Energy node : 08 ct1 : -526 ct2 : 1048 ct3 : 0
ct4 : 0 batt_Vrms : 240.99 pulse : 1 temp1_C : 25.6
Those lines all starting with “? G0” are indeed most likely noise, the “G0” indicates that the device is listening to “all groups”, so one would expect that to be both good and bad packets, however, there is a bug in the JeeLib code that means when you use “G0” it accidentally listens to “all but the last set group” so if your device was correctly set up for group 210 (for example) then switched to group “0” it will receive all except 210.
Easily fixed though, just send a “210g” string via your serial term with a cr & nl line ending to switch to group 210 (that’s the default used by OEM).
When you successfully set the group id it will change the output (the G0 will disappear) and the v command will return “[RF12demo.12] E i5 g210 @ 433 MHz” (assuming it is the only change).
Ordinarily this setting is usually managed by emonhub on the emonSD images.
The corresponding part of the help text is this line