RP2040 potentiometer platformio doesnt give right values

1

Hello.
I have a very simple circuit. Just a 10k ohm potentiometer, connected to GND, +3.3V and the middle pin of the potentiometer is connected to the 27 pin.

Now i programmed it to just print the analog value in serialprint on platformio.

however strangely. if i turn the potentiometer completely to the left, it gives me a analog value of 1023. and completely to the right, i get 1023 as well.
When i put it towards the middle. i will get values moving towards 0.
Typically I should get a 0 when turned to the left, and linearily increasing a 1023 when turning to the right.

Why is this happening? I didn’t have this problem with an arduino.

The code is very simple, I’ll show it here:
Thank you very much!

#include <Arduino.h>

// Define the pin where the potentiometer is connected
const int potentiometerPin = 27;  // GPIO26 (A0) for RP2040

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(115200);

  // Configure the potentiometer pin as an input
  pinMode(potentiometerPin, INPUT);
}

void loop() {
  // Read the analog value from the potentiometer
  int potValue = analogRead(A1);

  // Print the analog value (range: 0-1023)
  Serial.print("Potentiometer Value: ");
  Serial.println(potValue);

  // Add a small delay for better readability of serial output
  delay(500);
}

[EDIT: it doesnt matter if i use A1 or pin 27]

2

With what platformio.ini is that?

3

my full platformio.ini is this:

[env:pico]
platform = raspberrypi
board = pico
framework = arduino
monitor_speed = 115200
4

Okay. So that’s working with ArduinoCore-mbed. In the Arduino IDE, did you install that core or Arduino Pico? There are two different cores.

5

How do i know or find out what core I have installed?
Why do you mean in the Arduino IDE when using Platform io in VSC.
can i install some core in the libraries section of platformio?

6

Well do you get the Raspberry Pi Pico board from the “Arduino Mbed OS RP2040 Boards” path or from the “Raspberry Pi Pico / RP2040” path?

grafik
grafik1177×457 24.1 KB

7

I have only Arduino AVR Boards. and nothing else.

8

Oh. I read this as “I didn’t have this problem with the Arduino IDE”. Never mind.

Let me look into how to use analogRead() with the ArduinoCore-mbed properly… the pin mapping might be wrong, or the voltage is not reaching your pin properly…

9

Try removing this line.

Try measuring what voltage is reaching GP27 (which is A1) with a multimeter. This should be working normally.

10

Yeah i’m very confused.
I’ve commented the line u mentioned. Nothing changed.
This is what analogRead i get for different volt measurements of the potentiometer.
3.3V - analogRead: 1023
3.1V - analogRead: 960
3.0V - analogRead: 255
2.9V - analogRead: 511
2.5V - analogRead: 807
2.0V - analogRead: 1023
1.0V - analogRead: 1023
0.1V - analogRead: 1023

11

Is that the same for all analog pins? GP26 (A0) down to GP29 (A3)?

12

well some kind of similiar behavior happens with all pins.
But i just realized that when i read lets say:
int potValue = analogRead(A1);
I still get different analogRead values when i connect the pin to either GP26 or GP29.
It seems it doesnt matter what i put into the analogRead().

13

I also now tried another rp 2040. but i mean its the same model. its some cheap one for 2 euro from china. i wouldn’t think there is much difference.
i believe its still a software problem