AnalogReadFast got an issue with mixing inputs with Arduino Nano

[backflip2]

With my Arduino Nano v3 I got an issue with mixing of input signals. The issue is caused by the increase ADC clock to 1 MHz, and it leaves not sufficient time for the analog multiplexer to shift input channel.

The issue and a possible solution is described in these links:

https://forum.arduino.cc/t/higher-adc-clock-frequencies-cause-issue-with-adc-multiplexer-on-arduino-nano/1218027 https://forum.arduino.cc/t/is-it-possible-to-have-2-pins-analogread-sequentially-non-blocking/1209370/25