Add EnOcean ERP1 decoder

[wintersteiger]

This adds an EnOcean ERP1 decoder. It just decodes the radio frames into byte strings to be further interpreted by (existing) higher level decoders. I don't necessarily plan to extend this any further; it just serves as a quick test to see whether EnOcean devices are active and operating correctly. Together with higher level decoders, this can help to remove the need for an EnOcean-specific radio module in a home automation gateway, but I don't necessarily envisage that to be based on an RTL-SDR.

[zuckschwerdt]

That's really nice! Can you check that all indents are 4 spaces, continued lines 8 spaces, move data_make down after all the error returns. The do should preferably be a while, the initialization looks like that works.
Run ./maintainer_update.py if you can to ensure the readme and others are updated.

[zuckschwerdt]

Christoph, what is your (recommended) software setup? I'm using an EnOcean UART-Module connected to a Raspi running the "Python EnOcean" lib with added Secure PTM mode kipe/enocean#116 -- but that lib seems stale.

[wintersteiger]

Sure, no problem, all done.

I don't have a setup that I can recommend yet. For now I just have an RPI and a Micropelt MVA005 for evaluation, and various radio modules (but not an EnOcean-specific one). I really like the idea of a centrally-controlled, power-harvesting TRV, so I figured I'd give it a try. It uses yet another protocol, but this one's at least documented to some degree. Ideally, I'd like to send & receive via some cheap radio module like a CC1101 or an RFM69, as they should be perfectly powerful enough while also extremely cheap. (And I just hate the idea of buying a different radio module or gateway for each of my devices.)

[zuckschwerdt]

    unsigned pos = start + 11;
    unsigned len = bitbuffer->bits_per_row[0] - start;
    unsigned end = pos + len;

That's end = start + 11 + bitbuffer->bits_per_row[0] - start = 11 + bitbuffer->bits_per_row[0] -- oops;)
Possibly best to have just start += 11; just after the search.

[wintersteiger]

Good catch, that was indeed slightly off :-) Fixed now.