Pages: [1]   Go Down
Author Topic: Potentiometer  (Read 1453 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Full Member
***
Karma: 0
Posts: 235
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
« Last Edit: December 23, 2008, 01:44:11 am by dev_000 » Logged

London, England
Offline Offline
Edison Member
*
Karma: 4
Posts: 1026
Go! Go! Arduinoooo !!!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

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

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 361
Posts: 17303
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

0
Offline Offline
Full Member
***
Karma: 0
Posts: 235
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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??
« Last Edit: December 23, 2008, 06:47:09 am by dev_000 » Logged

0
Offline Offline
Full Member
***
Karma: 0
Posts: 235
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

problem solved guys... it was a problem with the pot... changed it and it works gr8...  ;D
« Last Edit: December 23, 2008, 07:01:46 am by dev_000 » Logged

0
Offline Offline
Sr. Member
****
Karma: 4
Posts: 323
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
What is the value of your pot? If it is 4 meg-ohms ( I see 4m in your post)

I think he's trying to say "from" - it must be some new abbreviation - it's everywhere I'd expect "from" to be. =)

A note to the OP: be careful about abbreviating common words.  A lot of the abbreviations you might have a tendency to use when typing an SMS message, for example, will conflict with known abbreviations in the electronics world.

!c
« Last Edit: December 23, 2008, 01:50:01 pm by drone » Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 637
Posts: 34602
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
A lot of the abbreviations you might have a tendency to use when typing an SMS message, for example, will conflict with known abbreviations in the electronics world.

Not to mention confuse old fuddy duddies like me.

If I said you were sick would that be good???
Apparently it depends on how old you are?  :-?
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 361
Posts: 17303
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'm too old to even know what SMS messaging means  smiley-wink

Lefty
Logged

London, England
Offline Offline
Edison Member
*
Karma: 4
Posts: 1026
Go! Go! Arduinoooo !!!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I have to admit I hate abbreviations. people use them all the time in work and it drives me nuts.
Logged

Pages: [1]   Go Up
Jump to: