W1209 temperature control module
Added 2025-10-30 00:35:08 +0000 UTCIt's a while since I've explored one of these modules, and this one has stripped the component count down to the absolute minimum.
I reckon it must be scanning the display and then pausing briefly to measure the temperature while all the LEDs are off and the supply is stable.
Comments
Pretty cool. I've seen various temp control boards on Ali and they are usually pretty inexpensive. Kind of amazing in the mass produced realm and useful it would seem. Thanks Big Clive.
Dave Frederick AKA @amorphuc
2025-10-31 03:41:05 +0000 UTCI understand why they've put that 26.7 Ohm resistor there, but if ADC conversions are not synchronized with LED multiplexing, VREF could be on the move giving high non-linearity which could in turn mess with any hysteresis you've got set in the control parameters. I would do the conversion at the end of the multiplex cycle, just before changing the LED drive pins. It may be possible to see what they've done with a scope.
Mike Page
2025-10-30 11:59:09 +0000 UTC
