A 10-bit A/D converter converts its input voltage into one of 1024 binary
values.  If the maximum voltage (the voltage reference) of the converter is
5V, then each of the 1024 steps represents 5V/1024 or about 4.88 millivolts.
So, if your converter reads 0001100100, that is 100 decimal, so the voltage
is 100*4.88 = 488 mV = .488V.

What the A/D converter gives you is the ratio of the measured voltage to the
reference voltage, in binary.

> -----Original Message-----
> From: Salah Mohammed [mailto:salah@HUGLE.CO.JP]
> Sent: Thursday, July 26, 2001 7:32 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [PIC]: ADC actual value Need help!
>
>
> Hello List!,
>     I don`t know if it is simple problem or not ...anyway ...
>
> Target Chip : PIC16F877.
> A/D  : 10 bits.
> programming language : PICC.
>
>   the problem is that how to calculate the actual value of
> the A/D readings,
> for example :
>  I am reading the voltage on a specific pin by using the
> A/D(10 bits) ,but
> the value in these 10 bits are not the actual value of the
> applied voltage
> so who can I converet it to the real value,
>
> A/D(10 bits) value                         voltage
> _______________________________________________________________
>
> 0000000000                                    0v
> .......................
>  ? I don`t
> know how to get the values here
> ......................                                         ?
> .......................                                        ?
> ......................                                         ?
> 1111111111                                     5v
>
> thanx in advance,
> Regards
> Salah Mohammed
>
> email: salah@hugle.co.jp
>
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>

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