Re: [avr-chat] ATmega16 Differential ADC Measurements

[Joerg Wunsch]

"Thomas D. Dean" <address@hidden> wrote:

> I have been looking at the ATmega16 adc in the differential mode in
> the STK500v2.  I measured the input to the two adc channels with a
> Fluke 27 connected directly to the pins.  I saw larger differences
> than I expected.

The datasheet specifies a resolution for 1x and 20x gains, and only 7
bits for 200x gain.  Did you account for this when setting your
expectations?

The data sheet of the ATmega16 doesn't have as many spec details as
that for newer AVRs, but for comparison, the ATmega1281 datasheet
specifies an absolute accuracy of between 9 and 18 LSB for the
differential measurements.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)