test su arduino

dovrei capire la velocità dell'ADC dell'arduino (o meglio del suo microcontrollore) e quindi inserire un segnale a rampa e ricavare LSB. come posso collegare un generatore di funzione e far acquisire il segnale ad arduino duemilanove? grazie

la velocità dell’adc arduino dipende dal prescaler.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1208715493/11
punti salienti:

The ADC clock is 16 MHz divided by a prescale factor. The prescale is set to 128 (16MHz/128 = 125 KHz) in wiring.c. Since a conversion takes 13 ADC clocks, the sample rate is about 125KHz/13 or 9600 Hz.

As it stands above, with FASTADC defined as 1, the 1000 calls to analogRead() take 16 msec (16 microseconds per call). With FASTADC defined as 0, the default prescale gives 111 microseconds per call.

Personally I’ve been looking into ways to make ADC processing less expensive in CPU cycles, to avoid calling analogRead() which burns over 100 microseconds sitting in a loop waiting for the conversion to finish. Turns out there’s a mode where the conversion finishing can generate an interrupt, so that’s the route I’m going, so the processor can be doing other things during the conversion (as long as the result is not needed right away!).