Resistance is generally measured using a multimeter. ExpEYES provides a limited facility to do this, using the SEN terminal. SEN is actually a voltage measurement terminal, with a 5.1kΩ resistor connected to 3.3V internally. The internal 5.1kΩ and the external resistor connected to SEN forms a series combination. By knowing the voltage across both and the value of one resistance, we can calculate the other using Ohm's law. The drawback of this method is that the accuracy is poor when the external resistance differs widely from 5.1kΩ. A resonable range is from 100Ω to 100kΩ.
Measure resistance using the SEN terminal.