boyer philippe

A to D conversion is going wrong

Discussion created by boyer philippe on Mar 27, 2008
Latest reply on Apr 14, 2008 by boyer philippe
I am using a S08AW32 microcontrel with 7 pinconfigured as Analog to digital channels.
I am sensing different level on these pins and everything seems cleans most of the time. An external IC sends me T° another gives me pressure in a bootle and  a third one a level in this bootle.
The "strange think" is that sometine and for a variable amout of time (very short time to 30 s) all the mesureament given by AD converter seems to be double :
For example T° is 25 °C  P is 50   L is 10 in normal condition and then
T° is 50 °c (a value that my Ic can not give)
P is 70 (in that means My AD channel give FF in 8 bit mode P=50 is near the maximum)
L is 20
The AD conversion is setup by PE beans with 8 values average asynchronous clock and software continious operation (interrupt by COCO bit)
Any suggestion ? Hardware troubles ? software troubles ?