Multiplexing PIC ADC

Started by Bakkal Adil February 25, 2005
It is possible to build a multiplexing circuitry for the PIC ADC? so we can have more channels than what a PIC have ( ex : 5 for 16F876 and 10 for 16F877 ).
Speed is not a important point in this.
 
(no external interfaced ADCs please)

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Message
>   It is possible to build a multiplexing circuitry for the PIC ADC?  
 
Of course, check for instance the analog multiplexers in the CD40xx range.
 

Wouter van Ooijen

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Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu
 




--- In , Bakkal Adil <dso310@y...> wrote:
> It is possible to build a multiplexing circuitry for the PIC ADC?
so we can have more channels than what a PIC have ( ex : 5 for 16F876
and 10 for 16F877 ).
> Speed is not a important point in this.
>
> (no external interfaced ADCs please)


As Wouter indicated, you can use analog multiplexers for this. Eg,
74HC4051 gives an 8:1 expansion. Also, depending upon how many
channels you need, some of the newer PICs have more A/D channels. Eg,
16F767 has 11, and 16F777 has 14. Rather than add several
multiplexers, I'd be tempted to just use several PICs, depending upon
how many channels total are needed.

I've used the '767, and had troubles with the compare module not
working properly, but the A/D's seemed to work ok. - dan michaels
www.oricomtech.com
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Yes you can use a CD4051 which is an analog switch 8 to 1 demultiplexer.
Jim
----- Original Message -----
From: Bakkal Adil
To: p...@yahoogroups.com
Sent: Friday, February 25, 2005 6:50 AM
Subject: [piclist] Multiplexing PIC ADC

It is possible to build a multiplexing circuitry for the PIC ADC? so we can have more channels than what a PIC have ( ex : 5 for 16F876 and 10 for 16F877 ).
Speed is not a important point in this.
 
(no external interfaced ADCs please)

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