WARNING MainThread RFM2Pi thread is dead

That’s likely. Of course, we didn’t know that it was running from an under-voltage supply, and resetting when it transmitted - possibly every time, or maybe just when the supply was low.

I did notice that the led was flashing every second, and that the VRMS readings only ever returned a value about once an hour (zero otherwise), and that it was always low - about 185. But I wasn’t sure if it needed a “factor” to scale it.