Very fast analogRead()

The standard Arduino analogRead() takes about 112us for the AVR and 425us for the SAMD21, this is very slow. The new function analogReadFast() takes just 21us.

Compatibility

• AVR boards: Arduino Uno, Nano, Mega, Leonardo, etc.
• SAMD21 boards: Arduino Zero, SAM 15x15, etc.

https://www.avdweb.nl/arduino/adc-dac/fast-10-bit-adc