RGB LED strip green LEDs cannot be dimmed to less than 50%

Question

I have an RGB LED strip which I want to control with my arduino uno, everything works fine, except for the green LEDs. They cannot be dimmed to less than 50%, because they will simply turn off.

I have this test code in my setup:

Serial.write("dimming green test started");
for(int x = 255; x > 0; x--) {
    analogWrite(greenPin,x);
    Serial.write(" - g:");
    Serial.print(x);
    delay(6);
  }
  Serial.println();
  Serial.write("dimming green test done");
  Serial.println();

And the green LEDs are fully turned on in the beginning, and at about 127, the just turn off. All the other colors are perfectly dimmable. I checked the energy usage, and green does only use a little more than the other colors, so that's not the problem.

Are green LEDs not dimmable? Or is this just an optical effect?

(I use a setup very similar to this one with one difference: but only use 5V, because my LED strip only needs 5V)

Answer 1

analogWrite only works on pins that support PWM. Those are the pins with the ~ next to it.

On no-PWM pins, analogWrite will set the pin to LOW, for all values lower than 128, and HIGH for all the higher values. Which is what you are experiencing.