lpcware

ADC channels interfere each other

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by Andrew24 on Thu May 06 13:29:32 MST 2010
Hello, i have a problem acquiring data from two ADC channels.
I have a timer to switch adc channels and start ADC every 1ms.
I also have connected two potentiometers , one to AD0, other to AD1.
I've disabled ADC interrupt. In the main program i'm polling ADC.
.AD0 and AD1 are selected as analog pins in IOCONFIG.
Heres the problem:
when i increase voltage in channel AD1, the voltage in AD0 alsos increases a bit.
I have tested it with multimeter. For example if i disconnect the second potenciometer from AD1, and measure the voltage at AD0 pin, from the firstpotenciometer, it shows for e.g 1.5V. If i connect second pot. i can control the voltage on AD0 pin! it seems that the channels are linked somehow in the lpc
Could you try to guess what's wrong?

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