In this wattmeter most of the actual work is done in software, the few external components only forward measurement values to the PIC where the actual measurements are done and calculations are made.

It measures:
- the Rms voltage (unit: Volt)
- the Rms current (unit: Ampère)
- the apparent power consumption (unit: VoltAmpère: VA, the product of both the rms Voltage and the Rms current). This value is also called “Complex power”.
- the real power consumption (unit: Watt) (= the one that you are going to pay for)
- the power factor (no unit, ratio of real power to the apparent power), is the same as “cosΦ” (cos phi) for sinusoidal voltages and currents.