Dangerous Prototypes

Dangerous Prototypes => Bus Pirate Support => Topic started by: JackJohn77 on June 21, 2019, 09:22:37 am

Title: MAX31855 Problem
Post by: JackJohn77 on June 21, 2019, 09:22:37 am
Hi, I'm having problem reading temperature from a max31855, I can't read a temperature from the thermocouple (adafruit library send a nan value) but the internal temp reading works.

So I think the problem either come from the thermocouple or the chip. I also observed when poking around with a multimeter that the T+ and T- pin are grounded to the ground pin itself, is that normal ?
Title: Re: MAX31855 Problem
Post by: tayken on June 23, 2019, 07:42:38 am
According to the code the chip thinks thermocouple is not attached: https://github.com/adafruit/MAX6675-lib ... 75.cpp#L40 (https://github.com/adafruit/MAX6675-library/blob/master/max6675.cpp#L40)

Probably there is a short somewhere. I would take off the thermocuple and start poking around with a multimeter to find any shorts on the board. Seeing how T- pin is right next to GND pin, there may be a short there.

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