I'm working on some serial comms traffic and trying to work out how a value is being derived from some hex data.

I'll give you an example, we have two data bytes $88 + $77 being transmitted in response to request for temperature data.

From these two bytes it generates a temperature value of 29C, now only one of the bytes may be being used of course.

A few more clues.

"This is showing the value of Motor Power Inverter Module Temperature Sensor.
Temperature of motor power inverter module is calculated at Motor Driver Module.
[Operating Range]

-40[°C] - 120[°C]
-40[°F] - 248[°F]

I though there might be an 0-5v 8bit dac involved in here somewhere and it's sending a voltage value from the sensor which is being converted in the software using some formula to the 29C

Any ideas on how that 29C is derived from that data?


Ditto on another temp sensor data serial chat we get $77 + $41 and it generates the value 36C on screen?

Same clues as above and same sensor range.

BCD? It doesnt appear to be ASCII? It doesn't appear to be a simple ofset etc?

Hoping for a PB genius to give me some clues?