12-bit PWM for LED lighting

Projects General Guidance
27

Dear GGE5

Thanks. This code worked well for me. Thanks for sharing.

GGE5:
I modified your code a bit to work. I had to set the pinMode of 9 to output before anything else. I had to erase your line setting TCCR4C because there is no Timer4 on my ATMEGA328 (and it was throwing an error), but also because TCCRxC is only active in non-PWM modes.

Also, when using C code, you don't have to set the HIGH and LOW registers separately, as the compiler takes care of that for you.

Here is the working code:

//12-Bit PWM on PIN9 using direct access to Timer1

//Fade in and out an LED connected to that pin

#define LEDValue OCR1A

const int PWMMax = 4095;
int value = 1;
int direction = 1;

void setup() {
  pinMode(9,OUTPUT);
 
  TCCR1A = (1 << COM1A1) | (1 << WGM11);                // Enable Fast PWM on OC1A (Pin 9)
  TCCR1B = (1 << WGM13) | (1 << WGM12) | (1 << CS10);  // Mode 14 Fast PWM/ (TOP = ICR1), pre-scale = 1
 
  ICR1 = PWMMax;  //Set the TOP value for 12-bit PWM
  LEDValue = 0;      //Set the PWM output to full off.
}

void loop() {
  //Fade the LED between 0 and PWMMax and then back to 0
  value += direction;
  if (value <=0){
    direction = 1;
  }
  else if (value >= PWMMax){
    direction = -1;
  }
  LEDValue = value;
  delay(1);
}




Thank you so much for your help!