Sensor went wrong

Hi, a problem appeared during the development of the project. The Project is a sensor to determine moistire of the skin. Put 2 wires that are connected to the arduino and it reads the values.

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

void loop() {
  int pot = analogRead(A1);
  Serial.print("Pot Value: ");
  Serial.println(pot);
  delay(400);
}

Previously, I used ordinary jumper wires as wires just to test, and everything worked correctly. Some time passed and now I put cooper wires instead of jumper wire, but now the program shows almost all the time 1023 when applied to the skin (previously with jumping wire was 800-900). Switched back to jumping wires and it also started showing a value of 1023. Would you know what the reason for this might be? Thanks and have a nice day!

Always show us a good schematic of your proposed circuit.
Show us a good image of your ‘actual’ wiring.
Give links to components.

Are you using A0 or A1 ?

This is where a schematic would help considerable. Your code is written to measure the output of a pot, that is all it does. All it will give you is a number between 0 and 1023. Provide a schematic and explain in detail exactly what your project is all about.

Ron

Be careful - you've got a bug-in-waiting there


Alright so I'm using Arduino Nano Every, the red wire is connected to 5V, blue - A1. I was told that by applying 2 wires to the face, the current will pass from one wire - skin - another wire, and then the value will be read, then due to the fact that the skin has its own resistance, the reading will decrease and after that, you can also determine the moisture level of the skin (actually resistance). I understand that I cannot immediately determine what is necessary, additional mathematical calculations will be needed, but it simply causes concern that the readings are already incorrect at the beginning of the development.

Add a 1meg resistor from A1 to GND.

If it’s better, try 560k to see what the results are.

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Galvanic Skin Response powered by Arduino – Thomas Kosch

Skin resistance will vary drastically with pressure of electrodes against skin, with perspiration, with freshly washed of sweaty skin.

Medical grade electrodes use a conductive gel to provide maximum conductivity and minimize resistance.

You will need some zeroing mechanism to make comparisons even on same person. Look into how lie-detectors work.

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As above , no ground reference for the analog input.
Your input will always read supply level.

Analog Input

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