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LTC6811-2 unable to sample NTC thermistors connected to GPIO 1 and 2

Gentlemen,

Connected two NTC thermistors to the GPIO 1 and 2. When start writing configuration registers with respective bits set for GPIO 1 and 2 noticed that they have been reset upon writing configuration in case if NTC thermistors are connected. What could be the reason of such behavior?

Thanks in advance!

Kind regards, A.

  • I'm not sure I understand the sequence of events here.  What sequence are you using to write the configuration bits at the start, and what causes them to be reset?

    The GPIO bits of the configuration register have different function depending on whether they are read or written.  See the row below from page 65 of the datasheet:

    Writing to the GPIOx registers configures the pull-down only.  Reading is the logic level.  So if you are reading back your configuration after writing it, you will need to mask the GPIO bits.  The REFON, DTEN, and ADCOPT bits can be verified to ensure the CFGAR0 write was successful.

  • Thank you very much! My bad! I have not read the specification carefully.