I am using this canbus shield on an uno with a TFT touchscreen.
I made a custom circuit board to allow everything to stack neatly. That all seems to work fine; it is just deciphering the protocol that is hanging me up. I also have one of these OBD readers bluetoothed to my phone through the Torque Pro app. I have a Y splitter cable that I have not used yet. At this point, I hope to use the logic analyzer to capture frames being sent and received. I know the codes being sent, just not the precise format. I have the feeling that it is the asking for the data that I am messing up, not getting the result I am looking for...OR, the system is getting the correct command, and it is in the reading, parsing, and calculating the returned frame that is wrong....or both.
For instance, I know the data the Torque Pro app is sending to request the transmission temperature on thermistor #1 is:
OBD Header Mode PID
701 22 1627
and the first byte returned is used to calculate the value via the formula A-40, yielding the temperature in Degrees C
So, if I plug the above 701, 22, 1627 into the structure to send, referencing a diagram I saw online that I can't find now to save my soul, I get back:
5671, 45A, 8, 0, 5A, 4, 0, 44, 1, 0, 0, 0,
As near as I can tell, 5A (90, DEC) s the first byte sent back, yielding 50 degrees C as the formula result, which is not even close. I believe the request should return just one data byte, yet I see a 44 and a 1 in the returned frame, indeed, I see the same values in every returned frame.
I hope all this makes sense....
....and yes, I will follow your advice and focus on only one value from now on until I have it solved.