AVR-Chat

This is an AVR group, not PIC. You can try one of the PIC lists for  
better help.

Jim Wagner

On Aug 4, 2009, at 7:41 PM, Yingdan wrote:

> Hello,
>
> I am using VREF+ and AVss for a potentiometer. Below is my setting:
>
> status_rp = 01 -- select bank 1
> CVRCON = 0b_1110_0110
> ANSEL = 0b_0001_1001
> ADCON1 = 0b_0010_0000	-- VREF+/AVSS
> status_rp = 00	 -- select bank 0
>
> The VREF+ pin gives ~1.2v and I can get the reading 0 - 255 in the  
> range of 0 - ~1.2v. The problem is the reading is unstable. When I  
> rotate the shaft from high to low, and low to high, I got different  
> readings for a specific position. From high to low, I got a relative  
> bigger reading and from low to high, I got a much smaller reading  
> for the similar position.
>
> I have no idea how to fix the problem. Can anyone help to take a  
> look at my CVRCON and ADCON1 registers since I am not confident with  
> them, or offer any help about what might be wrong?
>
> Your help is highly appreciated,
> Yingdan
>
>
> 



[Non-text portions of this message have been removed]