How to count the time while reading ADC ?

[Jerson]

I can offer you ideas only.

If you're comfortable with interrupts, get a timer to ring every 1mS and keep tracking a variable that increments every ring and then use that variable that throughout your program. Use this as the reference timer for everything on your system.

Other way, you use a hardware timer and poll it for overflow every fractional time. Then count a number of fractions equal to the 2 seconds you require. This does not need interrupts, but will block till the timer overflows

[richard]

its almost like deja vu again
same answer as here

[fratello]

Thanks for remember !!! I forgot the topic... Mea culpa, I became too old