NTC Thermistor for PID control w/ XIAO ESP32-C3

[jremington]

A good check is to use your multimeter to verify the resistance of the thermistor (out of the circuit), and the voltage at the divider junction.

The ESP32 ADC performance is very poor, and not very useful for such measurements. See

Fixing the non linear ADC of an ESP32

The ADC of the ESP32 has a – fully justified – bad reputation. The advertised 12 bits are practically 9 bit +3 bit noise. The V/ADC relation is not linear The first 0.21V of the input (by 11dB attenuation) are ignored I am proposing here a solution to get an acceptable result despite of all that drawbacks. usefull settings: // Settings for ADC analogSetWidth(11); // 11Bit resolution analogSetAttenuation(ADC_0db); 11 bit or 10 bit is much more realistic It is the attenu…