Thermocouple (or breakout board) suddenly not working

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alexandertmills
 
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Thermocouple (or breakout board) suddenly not working

Post by alexandertmills »

Ahoy,

I purchased a K-type thermocouple and a MAX31855 breakout board from you guys about a year ago. I tested it out when I got it and (to the best of my knowledge) it worked. I finally got around to the project I purchased it for and wired it up again last night. It worked. Now, however, try as I might, I cannot get a temp reading from it.

When I run the serialthermocouple example sketch I get the following as output.
Internal Temp = 0.00
C = 0.00
I had to modify the lcdthermocouple sketch, just so it'd work with the lcd backpack. When I run it, the following prints to the lcd.
INt. Temp = -127
T/C Problem
Now, you might assume I'm just in a really cold room, and to top it off I keep my boards in the freezer. Sorry, I don't think they'll spoil. :-P

At this point I'm pretty sure I somehow fried the MAX31855, or I broke my thermocouple. I tested the continuity of the thermocouple with my meter (it's okay), so I'm leaning towards the former.

Any suggestions on getting a firm diagnosis? I've tried this on an UNO and a Leonardo, and I still can't get anything else from serial or the lcd.

Thanks for your continued awesomeness,

Alexander
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alexandertmills
 
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Re: Thermocouple (or breakout board) suddenly not working

Post by alexandertmills »

Oops, didn't realize the pins are declared differently in the two sketches. Nevertheless, still having the same (similar) issue. No more "T/C Problem", but everything is reading 0 now.

:(

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adafruit_support_bill
 
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Re: Thermocouple (or breakout board) suddenly not working

Post by adafruit_support_bill »

Make sure that the thermocouple leads are firmly gripped by the screw-terminals. Those fine wires have a tendency to work loose if they are a little off-center when you first clamp them down.

It is also possible that the amplifier was damaged. These amps are very sensitive devices - designed to work with the micro-volt level signals from a thermocouple.

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