PECMAC i2c response doesn't match documentation

Software Particle
1

Hi all,

First time NCD user here. I’ve got this piece with a particle:

I am attempting to issue “Command 2: Read Device Identification Data” as per the documentation. I believe I am successfully sending and even receiving replies correctly, but the reply from the device doesn’t match what the documentation says to expect. My program outputs the below. Code is attached - and is really just a modified version of the i2c discovery program

----- Start TX -----
TX[0] : 42
TX[1] : 146
TX[2] : 106
TX[3] : 2
TX[4] : 0
TX[5] : 0
TX[6] : 0
TX[7] : 0
TX[8] : 254
----- End TX -----
TX Success!
----- Start RX -----
RX[0]: 0
RX[1]: 0
RX[2]: 0
RX[3]: 255
RX[4]: 255
RX[5]: 255
RX[6]: 255
----- End RX -----

Code attached here.
i2c.ino (3.5 KB)

2

Hi all the commands look correct assuming the address jumpers on your board are set to target address 42.

One thing I noticed though is the Wire.setSpeed() call. The current monitor boards don’t support a clock speed over 100KHz so this may be the issue.

3

Hi Jacob,

Thanks for the help. I tried both commenting out the setSpeed line and setting it to 100000 (100khz, default) and same result.

4

Well that’s the only thing that stuck out to me. Can you try the sample code over at: https://github.com/ControlEverythingCommunity/PECMAC/blob/master/Particle/PECMAC125A.ino and see if that’s working?