So I set up the Chipkit Uno32 with the temperature sensor TMP36 from oomlout.com, installed the serial port monitor on the laser pc and tested the system. All fine so far.
The data collected was pretty good as well.
The left shows room temp with the slight increase being the heat detected from my hand on the outside of case. The peak is where I took a very technical approach and waved a lighter under the sensor!
Unfortunately as soon as I turned the laser on it all went wrong! The data became massively noisy as you can see here:
The flat bit in the middle is where I turned the laser off.
The laser is not running, just sitting in ‘standby’. The only thing running is its controller and the steppers in a fixed position.
First thing I did was swap the USB port to a different PC, just in case, but no improvement. I also ensured that the Uno32 was not shorting on the body of the laser.
Next I turned off the laser but left all the cooling and extraction on, this gave good data!
So in summary, the laser is interfering with Uno32 / temp sensor despite them being isolated from each other. Great. I will try increased insulation and moving the Uno32 off the machine somewhere.
If anyone has any suggestions (or something really obvious I have missed) please let me know!