Add support for Neptune R900 flow meters

[jruby411]

I tried to follow the guidelines and suggestion given on the last pull request for adding the Neptune flow meters that use the R900 protocol. If there is anything else that needs to be fixed, let me know.

Thanks.

[zuckschwerdt]

Note that you could have added commits to #2175. Which would be preferred to track conversation and review.

[zuckschwerdt]

Looks like all my review notes were addressed, thanks. I'll need to look at this again, leave it as-is for now if you don't feel comfortable fixing the whitespace warnings.

[jruby411]

Sorry about not adding to the original Pull Request. This was nearly a re-write. I am still an amateur at this. Please forgive.

[roger-]

FWIW I tested this and it seems to be working.

Only issue is it's less sensitive than rtlamr and only picks up one R900 device, but that could partially due to the receiver settings (I tried to match rtlamr's settings with rtl_433 -f 912380000 -R 224 -s 2359296).

Would be great to have this merged.

[jruby411]

I have been running this code 24/7 on my server for the last couple of months without issues. I pick up a lot of meters with these settings: rtl_433 -f 912600155 -Y classic -s 2000k -R 224 Of course I am only interested in my meter, and it works great for that.

[roger-]

@jruby411 interesting because with those settings I only get my meter, whereas rtlamr gets several. Have you compared this to rtlamr?

Only difference I can think of besides the demodulator is the gain settings.

[magnetic-domelike-twisting]

Using the command parameters from @jruby411 rtl_433 -f 912600155 -Y classic -s 2000k -R 224 I'm picking up about the same number of meters as I was with rtlamr, just another data point. One other bit, and maybe it's me parsing it wrong, but compared to some other decoders, I see R900 report all lower-case consumption where others like SCM or SCMPlus output keys as first letter upper-case Consumption.

{
  "time": "2022-11-29 10:39:18",
  "model": "SCMplus",
  "id": 12345678,
  "ProtocolID": "0x1E",
  "EndpointType": "0x9C",
  "EndpointID": 12345678,
  "Consumption": 12345678,
  "Tamper": "0x0D08",
  "PacketCRC": "0x7D95",
  "MeterType": "Gas",
  "mic": "CRC"
}
{
  "time": "2022-11-29 10:39:22",
  "model": "R900",
  "id": 1234567890,
  "unkn1": 163,
  "unkn2": 4,
  "nouse": 0,
  "backflow": 0,
  "consumption": 1234567890,
  "unkn3": 0,
  "leak": 2,
  "leaknow": 0,
  "extra": "123456"
}

[roger-]

Any chance of merging this?

[zuckschwerdt]

Yes. I justed started catching up on PRs and this is coming up next now.