MCP9600 Help


I’ve got a Raspberry PI 4, a breakout board and the MCP9600 board (oh and a K type thermocouple). I’ve got it all connected, installed the relevant python libraries and got the test code running. However…

The value I’m getting back on the cold junction is “mostly” around 29c (in a room that’s only 20c) with the quite frequent 16.0625c and the very occasional 21c. It’s all over the place. At the same time that the cold junction is telling me 16.0625 the delta is giving me -0.0625. When the cold junction is returning me 29c the delta is mostly around -4c.

The values just seem a bit whacky?!?!?! Any ideas when might be going on, I’ve had a peek at the library but to be honest I can’t see how these values are being generated. Any ideas anyone?


I just saw an earlier post regarding baudrates which means I have noe eliminated the 16.0625 errors! Thanks!

However I’m still getting a cold junction temp of 29c in a room I know to be around 20c and a delta of -4c when the hot junction is right next to the cold junction. Any ideas? Is this just the way it is and I need to adjust in the software to get things “right”?



I’ve dropped the baudrate down to 10,000 and the highly erratic 16.0625 values etc have gone BUT, now I’m getting some very odd fluctuating deltas (hot, cold, delta below):

Resetting alerts
Configuring alerts
30.4 23.1 7.4
32.2 23.1 9.3
31.8 23.1 8.8
31.7 23.1 8.7
29.3 23.1 6.3
29.2 23.1 6.2
29.4 23.1 6.4
31.3 23.1 8.4
31.4 23.1 8.4
32.6 23.0 9.7
30.4 23.1 7.4
30.2 23.0 7.2
28.8 23.1 5.8
28.8 23.0 5.8
30.0 23.1 7.0
31.9 23.0 8.9
31.9 23.0 9.1
31.9 23.1 8.9
31.6 23.0 8.7
29.2 23.0 6.3
29.0 23.0 6.1

This is where the thermocouple and cold junction are on the same desk. “sometimes” it all settles down but quite rare. Anyone got any idea where the noise/interference etc might be coming from. I’ve tried physically separating the breakout board and the pi but to no avail.


I discovered if I remove my thermocouple completely I get

26.0 27.0 -1.1
26.0 27.0 -1.1
26.0 27.0 -1.1
26.1 27.1 -1.1

Suggesting the erroneous values are as a result of the thermocouple. Could I just have a dodgy thermocouple?


Replaced the thermocouple - now sorted. Now to get a replacement/refund on the thermocouple!