2 pot affecting each other

[rmdhn]

so say i have pot A, and pot B, When pot A increases in value pot B does so too, but not vice versa, and when in the code i ONLY read pot B it's FINE!
and pot A doesn't affect any other pots, just pot B,
on Arduino micro, Atmega32u4

i've tried double reading it but doesn't work
using delay(75); fixes the issue but has alot of noise, more delay is just unusable.

tried adding 0.1 uf and 0.01 uf capacitors to the input and gnd of pot B and doesn't work
every pot is 10k yet only these 2 are messed up
although they're different since they're the pots from the xbox 360 controller triggers.

codes :

1. double read, don't work

void setup() {
  Serial.begin(9600);
}

void loop() {
  int RT = analogRead(A6);
  RT = analogRead(A6);
  Serial.print("RT:");
  Serial.print(RT);
  Serial.print(",");
  Serial.print("LT:");
  Serial.println(analogRead(A8));
}

2. double read delay, 75 milliseconds, lowest i can get to it working

void setup() {
  Serial.begin(9600);
}

void loop() {
  int RT = analogRead(A6);
  delay(75);
  RT = analogRead(A6);
  Serial.print("RT:");
  Serial.print(RT);
  Serial.print(",");
  Serial.print("LT:");
  Serial.println(analogRead(A8));
}

3. only pot B, works perfectly

void setup() {
  Serial.begin(9600);
}

void loop() {
  int RT = analogRead(A6);
  Serial.print("RT:");
  Serial.println(RT);
}

4. nothing, as expected don't work

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.print("RT:");
  Serial.print(analogRead(A6));
  Serial.print(",");
  Serial.print("LT:");
  Serial.println(analogRead(A8));
}

edit: forgot to add that the reason i can't use code 2 is my main code measures a lot of things so having a delay is just no.
using millis() libraries also didn't work.

[UKHeliBob]

Please post a schematic of your project

What values are the 2 pots ?

[anon44338819]

Make sure the value isn't too low. 10KΩ should be good.

[cedarlakeinstruments]

Try this

void loop()
{
  analogRead(A6);
  delay(1);
  int a6 = analogRead(A6);

  analogRead(A8);
  delay(1);
  int a8 = analogRead(A8);
}

I vaguely recall that there was an issue with the analogRead not waiting long enough for the input to settle out after the multiplexer switched to a different channel so double reading with a delay on all channels should fix it.
But I took a look at some code I have that reads multiple ADC channels and I'm not having the problem, so perhaps my memory is foggy.

[rmdhn]

@rmdhn

every pot is 10k

Untitled_Sketch_ANALOG_schem.pdf (1.3 MB)

U1 and U2 are the pots in question
U1 is LT and U2 is RT

[rmdhn]

didn't work, code 2 is still the only one that works, 75 milliseconds still being the lowest delay

edit: forgot to add that the reason i can't use code 2 is my main code measures a lot of things so having a delay is just no.
using millis() libraries also didn't work.

[johnerrington]

Oh DEAR.

This is an excellent example of the reason for my feelings towards Fritzy.

How to make a schematic you can post.

When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th…

1: try disconnecting EVERYTHING else.
2: draw a schematic of how JUST the two pots are connected to the arduino.
3: Run this code, that does a dummy read after EACH change of input

void loop() {
  int RT = analogRead(A6);
  RT = analogRead(A6);
int LT = analogRead(A8);
  LT = analogRead(A8);
  Serial.print("RT:");
  Serial.print(RT);
  Serial.print(",");
  Serial.print("LT:");
  Serial.println(LT);
}

[rmdhn]

did not work

[pmagowan]

Very descriptive

[rmdhn]

I've already described the problem in full detail, it didn't fix it, got the same results. How is it not descriptive?

[pmagowan]

Read the post #7 and think about it

Look at the content of the post and compare to yours

[rmdhn]

here's the schematic

[rmdhn]

solution :
buy new pots.
the affected pot was deffective and not 10k, but 10,5k

[johnerrington]

@rmdhn

here's the schematic

Well its a start; it doesnt show what the 11,12,19 & 23 are; I'd guess - but why should I have to?

@rmdhn

on Arduino micro, Atmega32u4

@johnerrington

1: try disconnecting EVERYTHING else.
2: draw a schematic of how JUST the two pots are connected to the arduino.
3: Run this code, that does a dummy read after EACH change of input

.. Do I need to say you need to include your "SETUP" as well?

.. then copy what is printed to the monitor, and post it.