AVR-Chat

On Thu, Sep 22, 2005 at 02:28:49PM +0200, Ralph Hilton wrote:
> On Thu, 22 Sep 2005 12:11:25 -0000 you wrote:
> 
> >Hi
> >
> >I use sensor with output 0-10 volt 
> >
> >plz Help me how to connect 0-10 volt sensor to internal A/D
> >
> >(0-5 volt   working good but how to connect 0-10v)
> 
> Connect a 10k resistor from the sensor output to the ADC input and 10k
> from the ADC input to ground. that will halve the voltage on the ADC
> input pin. For safety I would add a protection diode from the ADC
> input to the +5 volt line.

If he uses the internal 2.56v reference then try 20k in series with the
sensor to the A/D input and 6800 from there to ground. Should give a max
of 2.54 volts at the A/D input. But I've found ATmega64 internal
references run 2.40 to 2.60 if powered from 3.3. YMMV.

-- 
David Kelly N4HHE, dkelly@HiWAAY.net
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Whom computers would destroy, they must first drive mad.