Jump to content
  • 0

MCC 172 clock won't sync



Hi, I purchased 3 MCC 172's a while ago for use with IEPE accelerometers. Of the three 172's when I run the same code on 2 of them that is supposed to record data to a .csv, it works however on the third it hangs. I have tracked the issue down to the specific 172's inability to sync the clock and set the sampling rate. For each run I have changed the address of the MCC 172 python is talking to so there shouldn't be an issue with addressing.

Any recommendations as to how to fix this would be great. Thanks


Link to comment
Share on other sites

1 answer to this question

Recommended Posts

  • 0


The clock is on pin 35, GPIO 19.  There is also a sync pulse on pin 31, GPIO 6.  GPIO 5 is the trigger signal, which is used if you are using the external trigger on one board to start the other boards.

The sync pulse will go low to synchronize all the ADCs so they are converting on the same edge.  When it returns high all the ADCs start their conversions on the next clock edge.

The 172 must be placed in clock master mode with mcc172_a_in_clock_config_write(address, SOURCE_MASTER, sample_rate) to have the signals appear on the header pins.  Otherwise, they are isolated from the header.

If the board will synchronize then it could be a bad header connector or a broken circuit. If it's less than a year old, a replacement may be possible but I would need the serial number off the board to check. If more than a year, there's nothing more I can do.

Best regards,

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...