Linear Potentiometer returning weird values

Other Hardware Sensors
1

Hello everyone,

I have been working recently with the Arduino Nano 33 BLE Sense and a 10k Ohm linear potentiometer (I haven't been able to find the data sheet, however this is where I purchased it: IMG_3523.mov - Google Drive (It may still be processing :P)).

My problem is that when I move the potentiometer, it returns 1023 at about 75% on the total length and ~860 at 100%. I've attached a small graph that displays this and here is a link to a video that shows the problem: video0.mov - Google Drive

I have tested it with a voltage meter and it shows a smooth 0 to ~4.8 volts while moving the slider both on the output of the potentiometer and the analog pin on the Arduino board.

Here is the code that I'm using.

// Arduino pin numbers
const int analogPin = A0;

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

void loop() {
  Serial.println(analogRead(analogPin));
  delay(50);
}

If anyone has an idea why this might be happening, I would love to know! I'm not sure if it's a problem with the potentiometer, the board, or something else. I'm sure there is something I'm missing...

Thank you! :slight_smile:

circuitdiagram
circuitdiagram743×741 76 KB

Potientometer
Potientometer677×678 13.1 KB

2

Welcome to the forum.

Arduino Nano 33 BLE Sense: https://store.arduino.cc/arduino-nano-33-ble-sense.
It is a 3.3V board. Using the 5V pin might damage the processor.
Use a analog input that you have not used or damaged yet, and connect the potentiometer to GND, 3.3V and the analog input.

Do you have a Arduino Uno lying around on your table ? That is the fastest and easiest way to test something. Then you can test the potentiometer.

You can let the Arduino IDE make a graph, even with multiple channels. It is called the Serial Plotter in the menu.

int channelA = analogRead( A0);
int channelB = analogRead( A1);
Serial.print( channelA);
Serial.print( ",");
Serial.print( channelB);
Serial.println();
3

Ah! Thanks, that works now :slight_smile:

When connecting to the board, do I need to always use the 3.3V output on the board?

I'm new to the electronics side of this, so there is much to learn...

4

Some Arduino boards are 5V boards, the analog input is from 0V to 5V, and the digital pins can output 0V or 5V. The Arduino Uno is such a board.

The newer Arduino boards are 3.3V boards. Everything runs at 3.3V. If you connect a LDR (light resistor) or NTC (temperature resistor) or a sensor, you have to use 3.3V.

A very few boards are "5V tolerant", they do not break when 5V is applied to a analog or digital pin. If the "5V tolerant" is not mentioned, then assume it is damaged with 5V.

To avoid problems, some boards have not even connected the 5V pin to something. I think your board has a VUSB jumper on the backside to make it possible to use 5V. But don't do that, you don't want 5V.

5

That makes sense!

Thank you for your help Koepel :slight_smile:

6

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