information re: multiplexer IC and ADC ICs

duffling

My project requires a number of POTs to be read·and the readings must be rock solid without any fluctuations


and im searching for some information so i can understand how multiplexer chips and ADC chips are used with the basic stamp 2 ,

so far ive found a few peices of information on these topics ..

i need circuit diagrams and / or tutorials if possible , does anyone know of any floating around ?

i still dont quite understand how these ICs are used with the basic stamp so i need to get my head around it ..

also .. i also need some IC names to get me started on my shopping list ..


any ideas?


·

Bruce Bates

duffling -

A little more information would be helpful. How many POTS are you speaking about?

The reading you get will only be as good as the pots you plan to use. Are you ready to invest in precision potentiometers, such as the 10-turn variety?

The best advice at the moment is probably to start small, learn how to operate a single potentimeter, then branch out from there. In general, all you will be doing is addressing more channels than you do with a single potentiometer, the rest of the code will be pretty much the same.

Just by way of example, the ADC0831 is a simple 8-bit, single channel ADC, and it's available from National Semiconductor (among others). The ADC0832, ADC0834 and ADC0838 are the multiple channel (2, 4, 8) versions of the same chip. The multi-channel chips all have built-in multiplerers and track/hold functions. You can download the data sheets from here: http://tinyurl.com/4zkvu .

Additional information on the National Semi web site, including general tutorials on ADC's, can be found here: http://www.national.com/appinfo/adc/

The Parallax Courseware to download which will be of interest is "Basic Analog and Digital" which can be obtained fro free here:
http://www.parallax.com/detail.asp?product_id=28129

That should get you started on the basics.

Regards,

Bruce Bates

Tracy Allen

The TLC2543 is an 11 channel, 12 bit ADC. Here is a URL with a tutorial for the Stamp:

www.emesystems.com/OL2tlc2543.htm#top

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Tracy Allen
www.emesystems.com

duffling

sorry , the number of pots will range from 6 to 16 i would imagine , since im planning to make a few versions of my project
i will also be using a serial LCD and a few buttons also ..

you mentioned the precision POTS , at the moment im using the garden variety which are ok .. but not really smooth enough for my project


i will dig into the info for the ADC and will try my best to nut it out .
thanks for the help