Guide how to transmit with code examples

[ToBeOrNotToArpi3]

Hi cpoore1,

I am impressed with your project and PoC video. What I was wondering is how do you process the data from, say, rtl_433 with your code and go manipulated to send it back. Can you please elaborate on this how this is done? (example code in steps)

[cpoore1]

I'll try the rtl_433 out tomorrow but if it looks like this...

• I think the last seven nibbles would be the Sensor ID (get rid of the first zero)
• Counter would be some two-digit binary string ("00","01","10","11")
• Battery status = battery_ok ("0" or "1")
• I'll have to check what the status and failed fields correspond to
• Convert kPa to psi by dividing by 6.895
• Temperature remains the same

The sensor I tested this code against was a PMV-107J so I'll try rtl_433 against the sensor and my transmit signal to see what shows up.

[cpoore1]

Here's what I learned:

• The first nibble (the zero) of the rtl_433 "id" needs to be dropped in my block (it only accepts seven nibbles)
• The battery status bit I'm using for my transmit block looks like it needs to be inverted to match rtl_433 (I'll fix it if it isn't rtl_433 that's broken)
• The "sensor_id", "counter", "self_test", "tire_presssure_psi", and "tire_temperature_c" fields in my block/signal work as expected in rtl_433
• The "self_test" field in my block is the "failed" field in rtl_433 (0=OK, 1=FAIL)
• The rtl_433 "status" field is an integer calculated from five bits comprised of a combination of fields: [counter, counter, unknown1, unknown2, self_test] msb->lsb

That should be enough to recreate the output from rtl_433 and enter it into my block manually.

[ToBeOrNotToArpi3]

Hi cpoore1!

Massive thanks for this input, nice work!