my breadboard is reversing input from photocell?

So I've just noticed when I was doing rewiring and running a simple program whereby the photocell detects less light than 300 it will switch led on. But whenever I pressed my finger down on the sensor it still showing in the debug that there was plenty of light.

So I decided to put in a debug statement to check the the darkness / light values on the photocell when I pressed my finger on the same and I found that when the sensor was plugged on the right side of the breadboard (f,g,h,i & j) when i didn't have finger over it kept a value of 434 but as soon as I put any form of darkness on the sensor it would rise up to 700-800.

So then I decided to plug in the same sensor & wiring onto the left side of the breadboard (a,b,c,d & e)
and the result was the exact opposite with the resting value being of 434 and when finger was placed down the value would drop down to 100-200.

Does anyone have a sort of explanation as to 2 sides of the breadboard offered 2 completely opposite readings for the same sensor?

I guess the breadboard has a "good" side and an "evil"side. Perhaps a schematic of your setup and the code you are using would shed some "light" on the problem.


Setup - see attached:
Minus the power & GND being plugged directly into the breadboard rather than the components

Code is as follows:

int lightSensorStatus = analogRead(lightSensorPin);  // read status of pin value
   // Serial.print(lightSensorPin);
    if (lightSensorStatus <= 300)
      digitalWrite(ledPin, HIGH); // Turn LED on
      Serial.println("\nLight Sensor is DARK, LED is ON");
      digitalWrite(ledPin, LOW);
      Serial.println("\nLight Sensor is LIGHT, LED is OFF");


dpd you test to plug in the sensor on others places of same breadboard ?

Yeah I tested in numerous positions on the breadboard on right side before moving it over to the left side. All was the same result until I switch it over to the left side which then produced the exact opposite result.

It sounds like you somehow switch GND and Vcc in the process. That would cause this exact result. Do check connections and voltage levels with your multimeter.

Just turned on the system again and now in bright light its now claiming its completely dark yet I have a torch and shined at it. This breadboard is irritating..

Its constantly stuck on a value of 56 regardless which side of board I place it on.

Another update which I've found rather weird. I took out the vcc & gnd cables out of the breadboard and used 2 wires to connect both sides of the breadboard and someone its retaining / generating power to cause a buzzer i have set aside for other components of my project to power up and generate noise.