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Topic: Potentiometer (Read 1 time) previous topic - next topic

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Dec 23, 2008, 07:42 am Last Edit: Dec 23, 2008, 07:44 am by dev_000 Reason: 1
guys i am trying to take readings 4m a pot.. i am using the foll ckt...
http://www.mediafire.com/imageview.php?quickkey=ez5kmxdzyjn&thumb=5

intially wen i connected the ckt i got values ranging from 100 to 1024... now wen i am connecting the ckt (the same one) i am getting variations 4m 150 to 400 range... can anyone tell me y this happens???
here is the code i used...

int val;
void setup()
{
  Serial.begin(9600);
 
}
void loop()
{
     val=analogRead(2);
     Serial.println(val);
}

thanx in advance

Mike Mc

Maybe the pot is dirty or your Voltage source is not regulated and hence different each time you use it?

retrolefty

What is the value of your pot? If it is 4 meg-ohms ( I see 4m in your post) then that is much too high as the impedance of the input of the Arduino will act like a voltage divider thus lowering your readings. The link you attached shows using a 10k pot and that should work fine.

Lefty

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#3
Dec 23, 2008, 11:46 am Last Edit: Dec 23, 2008, 12:47 pm by dev_000 Reason: 1
i am using a 10k pot... voltage source i am using is the one in the arduino... 5V port...
I would also like to know if something is faulty... voltage source isnt faulty chked it with a multimeter... any voltage i give should give a variation between 0- 1024 rite??

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#4
Dec 23, 2008, 01:01 pm Last Edit: Dec 23, 2008, 01:01 pm by dev_000 Reason: 1
problem solved guys... it was a problem with the pot... changed it and it works gr8...  ;D

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