Andre Abelian wrote:

> Hi to all engineers.
> I am working with 16c71  to learn more about it.
> this is what I know about it.
>
> 1. adres        A/D result will be in this register after conversion
> 2. adcon1    to setup analog inputs and Voltage reference
> 3. adcon0   conversion clock, analog channel select, and more
>
> I played with one A/D converter I got good result.
> since I see only one result (adres) register  I do not imagine
> using all four A/D converters where are you going to put
> results from each A/D converter at the same time.
>
> Could you please explain how it works.
>

The A/D inputs are multiplexed to one A/D only. You haveto select which
input you want to sample. The result of the
A/D is alway in ADRES, so you have to pick the right channel.
To do this, you have to set up ADCON0. I didn't have a
PDF file for the 16C71 on-hand, but to explain it, here is
the breakdown for the 16C74 (see bit 5-3) :

ADCON0

bit 7-6: ADCS1:ADCS0: A/D Conversion Clock Select bits
            00 = FOSC/2
            01 = FOSC/8
            10 = FOSC/32
            11 = FRC (clock derived from an internal RC oscillator)
bit 5-3: CHS2:CHS0: Analog Channel Select bits
            000 = channel 0, (RA0/AN0)
            001 = channel 1, (RA1/AN1)
            010 = channel 2, (RA2/AN2)
            011 = channel 3, (RA3/AN3)
            100 = channel 4, (RA5/AN4)
            101 = channel 5, (RE0/AN5) (1)
            110 = channel 6, (RE1/AN6) (1)
            111 = channel 7, (RE2/AN7) (1)
bit 2: GO/DONE: A/D Conversion Status bit
            1 = A/D conversion in progress (setting this bit starts the
A/D conversion)
            0 = A/D conversion not in progress (This bit is
automatically cleared by hardware when the A/D conversion
            is complete)
bit 1: Unimplemented: Read as '0'
bit 0: ADON: A/D On bit
            1 = A/D converter module is operating
            0 = A/D converter module is shutoff and consumes no
operating current


--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
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