> As long as I account for capacitor charge time, can I turn the A/D off
> and on at will?  Right now I just leave it on...
>
> The first line in AD_RA0() leaves the A/D enabled for the life of the app.
> The second line does a delay for A/D capacitor charge time before ADGO.
> I've placed a comment where I wonder if I could/should turn the A/D off.
>
> - Bri
>
>
> void AD_init(void)
> {
>   OPTION = 0x87;             // Set TMR0 prescaler, and 1:256
>   ADCON1 = 0x02;             // Left justify result, 3 analog channels
> }
>
> unsigned char AD_RA0(void)
> {
>   ADCON0 = 0x41;             // Fosc/8, A/D enabled
>   DelayUs(20);               // Allow time for A/D capacitor to charge
>   ADGO = 1;                  // Set the bit to start the conversion
>   while (ADGO)               // Wait for the conversion to complete
>     continue;                //
>   //// could/should disable A/D here?  (w/ADCON0)
>   return ADRESH;             // Return the AD value (just the top 8 bits)
> }

>> As long as I account for capacitor charge time, can I turn the A/D off
>> and on at will?  Right now I just leave it on...
>>
>> The first line in AD_RA0() leaves the A/D enabled for the life of the
>app.
>> The second line does a delay for A/D capacitor charge time before ADGO.
>> I've placed a comment where I wonder if I could/should turn the A/D off.
>>
>> - Bri
>>
>>
>> void AD_init(void)
>> {
>>   OPTION = 0x87;             // Set TMR0 prescaler, and 1:256
>>   ADCON1 = 0x02;             // Left justify result, 3 analog channels
>> }
>>
>> unsigned char AD_RA0(void)
>> {
>>   ADCON0 = 0x41;             // Fosc/8, A/D enabled
>>   DelayUs(20);               // Allow time for A/D capacitor to charge
>>   ADGO = 1;                  // Set the bit to start the conversion
>>   while (ADGO)               // Wait for the conversion to complete
>>     continue;                //
>>   //// could/should disable A/D here?  (w/ADCON0)
>>   return ADRESH;             // Return the AD value (just the top 8 bits)
>> }
>
>I see no reason you couldn't turn it off as long as you observer all the
>rules when turning it back on again.  I've never done it this way.  Why do
>you want to turn off the A/D?  will you not use it again or are you trying
>to save power?
>
>
>********************************************************************
>Olin Lathrop, embedded systems consultant in Littleton Massachusetts
>(978) 742-9014, olinspam_OUTembedinc.com, http://www.embedinc.com
>

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