I have created another sketch for the AVR (UNO) that runs the ADC test using different pre-scaler settings.
The results on an UNO
Arduino UNO I/O Speed Tests Over 1000 Iterations.
ADPS2 Analogue Pin Read Takes About 4.96 Microseconds.
ADPS4 Analogue Pin Read Takes About 6.52 Microseconds.
ADPS8 Analogue Pin Read Takes About 10.04 Microseconds.
ADPS16 Analogue Pin Read Takes About 17.06 Microseconds.
ADPS32 Analogue Pin Read Takes About 30.12 Microseconds.
ADPS64 Analogue Pin Read Takes About 56.10 Microseconds.
ADPS128 Analogue Pin Read Takes About 112.00 Microseconds.
AVR_ADC_Speed_Test.ino (1.28 KB)