What should be the reference voltage of ADC ? What is the reference voltage of Seeeduino V4.2 for analog input pins? GSR sensor with unweared electrodes should be adjusted with screw driver to read 512 ADC code. What voltage referes to 512 code ?
The Seeeduino V4.2 is of 10 bit resolution (so the integer values from (0-(2^10) 1023)). This means that it will map input voltages between 0 and 5 volts into integer values between 0 and 1023. So for every (5/1024= 4.9mV) per unit. so 512 ADC code means 2.5v