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

[Kevin Cozens <>]

Greetings, all.

Four more days have passed and I'm still no closer to figuring out what is 
wrong with the routines which are reading the A/D converters. I've minimized 
the differences between use of the routines as a test program vs. use in my 
application.

When the test program polls once per second the voltages are stable. When my 
application runs, I get about 1 good reading out of every 5 (the 0.382 0.382 
readings). See sample runs of the test program and my application below. ALl 
readings are printed from inside the routines which read the A/D inputs so I 
don't see it as a case of memory getting inadvertently over written.

With the client hoping I can deliver the product at the end of the month and 
my being stuck on this problem for the last week and having no idea what is 
going wrong here, all I can do now is to cheat.

I'll have to modify my application to read the first two channels about 10 
times per second, throw out any negative readings, readings greater than 3.3V, 
and any readings where the two channels differ by more than 10mV. It isn't 
something I really want to do but it seems I have no other option unles 
someone has any explanation as to what's going on.



$ ./adc_7250 |grep readings
A/D readings: -0.242V -0.241V 0.185V 0.105V 0.104V
A/D readings: -0.243V -0.242V 0.185V 0.105V 0.103V
A/D readings: -0.241V -0.241V 0.185V 0.105V 0.104V
A/D readings: -0.239V -0.238V 0.186V 0.105V 0.103V
A/D readings: -0.242V -0.240V 0.185V 0.105V 0.103V
A/D readings: -0.242V -0.242V 0.185V 0.105V 0.103V
A/D readings: -0.242V -0.242V 0.185V 0.105V 0.103V
A/D readings: -0.240V -0.242V 0.185V 0.105V 0.103V
A/D readings: -0.240V -0.239V 0.186V 0.105V 0.103V
A/D readings: -0.242V -0.242V 0.185V 0.105V 0.103V

$ ./myapp |grep readings
A/D readings: 0.382 0.382 0.185 0.105 0.103
A/D readings: 0.382 0.382 0.186 0.105 0.103
A/D readings: -0.108 -0.167 0.185 0.105 0.103
A/D readings: -0.244 -0.244 0.185 0.105 0.103
A/D readings: -0.244 -0.244 0.185 0.105 0.103
A/D readings: 0.002 0.130 0.185 0.105 0.103
A/D readings: 0.383 0.382 0.186 0.105 0.103
A/D readings: 0.117 -0.028 0.185 0.105 0.099
A/D readings: -0.243 -0.243 0.185 0.105 0.103
A/D readings: -0.244 -0.244 0.185 0.105 0.103
A/D readings: 0.001 0.129 0.185 0.105 0.103
A/D readings: 0.383 0.382 0.186 0.105 0.103
A/D readings: 0.116 -0.028 0.185 0.105 0.103
A/D readings: -0.244 -0.244 0.185 0.105 0.103
A/D readings: -0.244 -0.244 0.185 0.105 0.103

-- 
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





 
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