Protocol documentation

[antirez]

Hi, thanks for providing this code. I was wondering if you reverse engineered the protocol using a BLE sniffer or alike (like nRF tools) and implemented it in Python, or if there is a protocol specification somewhere. Thanks.

[cdump]

Hi, #4 (comment)

[antirez]

Ok, this is great. Please in the case I would like to write a documentation for the protocol, could I send you questions in this issue to get your help? Thanks.

[cdump]

I can’t guarantee 24/7 support for all questions, but I’ll try to answer here occasionally

[ckuethe]

Also, the free Microsoft developer VMs running under qemu on a Linux host work for capturing USB traffic with Wireshark. You can run the app with debug turned on, and see what goes on the wire.

[antirez]

Thank you

[RamonBeast]

@cdump if you have any notes to share, even if messy, feel free to share please, I'd be happy to start jotting down an initial document.

[cdump]

@RamonBeast I don't have any notes, sorry. All the knowledge I have is already in the code (variable names, a few comments)

[RamonBeast]

Noted then, thank you!

[caquino]

Hi @antirez, Did you manage to make progress with the documentation? I'm interested in integrating rng-tools and radiacode to use it as an entropy source.

Is there anything I can do to help or collaborate? My idea was to implement a similar library to what we have here, but in C, and then integrate it into rng-tools.

BTW, been using your open source work for a long time, thank you for all your work :)

[ckuethe]

Since this is open and there isn't a Discussions section, let me drop a couple of observations here:

• flag 0x2000 in Event, RareData, and DoseRateDB seems to indicate charging. The bit is cleared when the blue charge light goes off.
• flag 0x4000 is cleared and 0x2000 is set in RealTimeData when the blue charge light goes off

After patching databuf.py a bit, it appears the that the following Event ids are defined:

• TOGGLE_SIGNALS = 3
• DOSE_RATE_RESET = 4
• BATTERY_FULL = 7
• CHARGE_STOP = 8
• DOSE_RATE_ALARM1 = 9
• DOSE_RATE_ALARM2 = 10
• DOSE_ALARM1 = 12
• DOSE_ALARM2 = 13
• COUNT_RATE_ALARM1 = 20
• COUNT_RATE_ALARM2 = 21

Edit: I'd guess that DOSE_RATE_OFF_SCALE, DOSE_OFF_SCALE, and COUNT_OFF_SCALE might be event ID 11, 14, and 22 respectively but I don't have any convenient ways to test that. I'm not close enough friends with my dentist to borrow the x-ray machine after work... ☢🦷

[ckuethe]

The configuration command gives some useful insight into the various messages the radiacode sends. The configuration message a nested INI-style file and can be parsed with the configobj python module.

The fields that make up messages (GRP_something) seem to be called channels (CHN_something).

If a field definition contains an Expr member, look for a couple of extra members called P1 and P2 (implicitly 0). Use them to compute new = orig * P1 + P2.

By way of example, temperature is declared as "CHN_Temperature": {"Id": "8", "Sensor": "AS6212-AWLT", "Unit": "°C", "DType": "5", "RType": "1", "MinVal": "-20", "MaxVal": "40", "Expr": "1", "P1": "0.01", "P2": "-20"}. When your device reports the raw temperature is 4220, the actual temperature is 4220*0.01-20 = 42.20-20 = 20.2C.