Stable Adc Reading Routine

[Pic_User]

Dear All
I replaced my own routine for ADC readings with Melanie's just to see if there would be any difference in displayed voltages.
I found out that there was always an increase in steps of 30mV(remember that I display with a resolution of two decimal digits) instead of my previous output in short bursts of gradually increasing values by 10mV.
So I came to the conclusion that my problem lies with the resistive divider that I use in order to be able to read voltages up to 30V.This is division by 6 and with the 0,004887 V / step(due to 5V max./1023 for 12F675) we arrive at apx. 30mV / new step which is unavoidable.
I think that I have to use some OPamp method(differential) to read voltage without stepping down through a ressistive divider.
I would welcome any thoughts and/or suggestions on the subject.
I thank all of you and especially Melanie(for the exceptional/disciplined programming techniques she uses) for the time you dedicated for me.
Also please forgive any grammar mistakes I make since I am only a native Greek .

Bill

Hi Bill

Take a look at this post.
http://www.picbasic.co.uk/forum/showthread.php?t=8070

You will have to extrapolate the Voltage up from the 12 Volt example given. Hope it helps….

Melanie doesn’t really make fun of grammar. We have a running joke about the difference between REAL English and American English. She was just catching a goof of mine. Your English is better than mine!

-Adam-