ADC Sensor Measurements Activity

supply voltage is 3.3 volts which reads as 4095.

Voltage at the voltage divider point V-mid (middle of divider)

We have a 10 K resitor going from the mid point to ground.

We now calculate the current flow through the resistor:

Suppose V-mid is 1.0 volt

V = current * resistance or
current = voltage / resistance
current = 1.0 / 10,000 ohms
0.1 millamps

To get resistance of the thermistor:

Resistance = V / I

R = 2.3 / 0.1 milliamps (R will be in K ohms because we divide by milliamps).
R 23 K ohms.


Larry Kiser
April 18, 2023