In a recent blog post on omzlo.com, [Alain] explains how they found a bug in the Arduino SAMD21 analogRead() code which causes the output to be offset by between 25 mV and 57 mV. For a 12-bit ADC ...

The circuit will output about 0dBm into 50 ohms. The power detector is an Analog ... from very low frequencies to 500MHz. [Brett] uses a Python program to process the data from the Arduino.

Renesas Technology has a low voltage flash microcontroller family with on-chip 10-bit A/D conversion that has a wide sampling range. Anticipated low power applications include water and gas meters, ...