AVR-Chat

At 11:33 AM 5/11/2004 -0600, Craig Limber wrote:


>Mike wrote:
>
>> I didn't see anything in your code that allowed some settling time
>> after you switched the mux...
>
>Hmmmmmm... 
>
>The manual says the sample and hold cap is 14pf.  My low-pass filter on
>each channel has a 1k resistor.  I didn't see anything in the datasheet
>for the Sharp range sensor's output impedance.  Do you have any
>suggestions how long I should wait for the input voltage to settle? 

This is for the amp on the other side of the mux to settle, not the input voltage.

>I will try moving the MUX switch code to allow for settling time as 
>well.  Thanks.

IIRC, I was able to do this pretty simply, and in the end, every time the conversion completed, I was able to switch inputs, and start the next conversion, without wasting any significant time in the ISR. 

But, it's been a while, and I don't remember exactly how I solved that one. 
I can dig it up, if you don't resolve this pretty quickly.