[ts-7000] Problem polling A/D's once per second

[Kevin Cozens <>]

Greetings, all.

With the kernel module issues handled, I only have one (hopefully) last 
remaining hardware issue to deal with. Namely, the A/D converters.

I am using a slightly modified version of the adc_7250.c sample/example file 
(http://www.ve3syb.ca/tmp/adc_7250.c) that shows how to read the A/D 
converters. It seems to work fine when I run it as a standalone test program 
(ie. define TESTPROG) but not when I use it in my application.

The A/D voltages from all five channels seem stable when I run the test 
program from a command line. I run it multiple times by hand (using command 
line recall). The voltages displayed by ./adc_7250 are stable give or take 
minor variation around the third decimal point.

When I call the ADC_ReadAllChannels() routine once per second in my 
application, the voltages I read are unstable. They are all over the place. I 
may get one or two readings in a row that are about what I expect. Other times 
they can be negative or up to 4V.

The sample file must be missing something regarding the control of the A/D. 
I'm wondering if someone can spot what it is. I'm still trying to look over 
the A/D info from the EP9301 manual.

Is the problem in the check for whether the A/D is busy (ie. in the middle of 
a conversion)? I saw some note about needing to check for a low to high (?) 
transition on the busy bit. Haven't had a chance to test that yet. Even still, 
it is odd that the routines work reliably when I run the program from a 
command line to poll the A/D's.

-- 
Cheers!

Kevin.

http://www.ve3syb.ca/           |"What are we going to do today, Borg?"
Owner of Elecraft K2 #2172      |"Same thing we always do, Pinkutus:
                                 |  Try to assimilate the world!"
#include <disclaimer/favourite> |              -Pinkutus & the Borg


 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ts-7000/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/ts-7000/join
    (Yahoo! ID required)

<*> To change settings via email:
     
    

<*> To unsubscribe from this group, send an email to:
    

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/