Add support for Revolt ZX-7717 power meter

[zuckschwerdt]

S.a. discussion #3122

Draft:

• needs to handle other message lengths,
• could also output apparentpower_VA,
• key pf should likely be powerfacor.

[AkaBoing]

it works,
thx Christian.

[AkaBoing]

output apparentpower_VA is in work,
same for pf > powerfacor.

[zuckschwerdt]

We only need to decide wether apparentpower_VA would be good to have. It's not in the data and not clear if I * U here is actually real VA.
Same for pf or powerfactor, nice to have and shown on the main unit, but it's not in the data -- we need to decide common keys and something of a policy for power meter decoders.

A more interesting thing would be to collect messages of different lengths and handle those somehow. At least checksum and log the payload.

[AkaBoing]

a DIEHL meter shows the same PF, both for inductive ( a 185W compressor) and a 25W halogen lamp.
V*A is not always VA, if a switching Power Unit or Inductive Unit is used, but thats another story.
apparentpower_VA is not shown on Revolt Monitor zx7716 !
So drop both ?
Give me a hint please.
And for the other messages, i have no clue what to do with them.

[zuckschwerdt]

I'm leaning towards not outputting VA or PF. We don't know if V and A are true RMS derived over some time or just some instantaneous values. A user wouldn't know that those outputs are simple (VA=V*A and PF=P/VA) guesswork.

I'll add checksumming and dumping of other messages soon.

[AkaBoing]

its all about clipping, the zx-7717 HF output is far too strong..
With a bad 866Mhz !! antenna i get a better signal- nearly no clipping.
And (im logging for 2 hours now), no further message beside 120 (112)

i dropped PF and VA

[AkaBoing]

Sorry for IBIS callback, im testing on another PC with -R 80 , but with your code.