On Thu, 13 Dec 2001, dr. Imre Bartfai wrote:

> If you want to have a relatively exact reference at low cost, use
> LM336-5.0. I agree with another colleagues the some mA's at the
> measurement of 12V is no concern (I guess you want to power the PIC from
> the PC also). Another remark: I guess 16F877 would an overkill
> here. 16F870 would suffice (28 pins also, has an USART, too, costs less
> than half of the former one).
>
  Imre, what do you think about an 627/628 with an extra operational
amplifier chip (with 2 OA inside ) and a simple slope AD converter.
There is an application note ( with 16C622 I think) on Microchip CD.
Will be definitely cheaper than 16F870, but a little dizzy in software.

Vasile

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