I was going to roll my own energy monitoring, but instead I thought I’d buy a ready made solution expecting it to be a lot easier and quicker. Sadly this has not been the case so far. And I’m struggling to work out what’s going on, and I’m kind of wishing I’d stuck with the original plan, as at least I’d have some understanding of what I’d done, and be better able to diagnose it, having built it.
Anyway… I got my EmonTx V3, 3x CTs, flash pulse sensor, and RFM69Pi through and tried to make it all work last night and this morning.
I will try and split this post into two pieces, though they somewhat overlap :-
1st, I think my EmonTX may be faulty.
2nd I think my RFM69Pi may be faulty.
I am flummoxed and surprised at how unlucky and unlikely this is, but I think I’ve done the necessary due diligence to rule out other possibilities.
My EmonTX is connected up, appears to be doing the expected lights-flash sequence on boot, and then flashes once every 10s approximately. So it feels like that is OK. The antenna is firmly attached. All looks well, visually.
I initially tried receive the EmonTX’s transmissions on the Pi using the RFM69Pi. This did not go well. I initially thought that a screen I’d had on the GPIO pins might be causing a conflict, but I did do the necessary to remove support for the screen and switch back to HDMI. Still no joy. I also wondered if If somehow I’d been supplied a board that had not had its firmware loaded, so I followed the instructions to try and re-flash the firmware using avrdude. This did not appear to work. Oddly the board does flash its LED from time to time. So it seems “somewhat alive”.
Essentially minicom using the relevant parameters shows nothing. And flashing the firmware gives strace broken pipe errors.
So thinking I’d try another route, and figuring perhaps I had a faulty RFM69Pi, I thought “I know what I’ll do, I’ll use rtl_433 to receive it”. If you’re wondering why I bothered with a RFM69Pi at all, knowing I had the SDR option, it’s because I want to use the SDR to receive my 868 MHz weather station.
Here is where it gets weird.
I cannot see the EmonTX on rtl_433 either. And I KNOW my SDR is fine, because I can see several of my 433 MHz temperature sensors dotted around. So that is “known good”.
I moved my SDR and Pi to be within 2ft of the EmonTX. Still nothing seen on rtl_433. Re-tested with the RFM69Pi board. Still nothing.
So the TL;DR version is:-
- I think maybe my RFM69Pi may be faulty.
- I am pretty sure my EmonTX is faulty; having now tested it with a receiver that is ‘known good’ for other 433 devices.
Am I just really unlucky? I don’t want to think that OEM is a pile of junk, but having spent £ on this, I can’t help feeling disappointed. If it had been one thing, I think I’d have felt “oh well, just unlucky” but (and again I’d be delighted to be proved to have been doing something stupid and everything is fine) I feel I’ve done the necessary to narrow down the location of at least one fault, and it feels like the EmonTx is not Txing.