There is no need to calibrate the adc since the ESP32 has a built in conversion from the adc reading to the actual voltage. So instead of reading the ADC value, I read the voltage. This is better because the Voltage and ADC curve is not perfectly linear.
I have managed to write a table which consists a value for each temperature. Then I just find the closest match and determine what is the temperature.
I have managed to write a table which consists a value for each temperature. Then I just find the closest match and determine what is the temperature.