Automatic-rock.nl

When I had a shortage of ccp pins I wrote this simple software pwm for MikroC:

Source code
   
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unsigned int PWM_fade=200;   void Delay(int num){                     // De delay functie   while(num>0)   num--;}   void main() {   while(1){     for (i = 0; i <= PWM_fade; i++){     //Led1 van aan naar uit; Led2 van uit naar aan;            Led1 = 1;             Led2 = 0;             Delay(PWM_fade - i);             Led1 = 0;             Led2 = 1;            Delay(i);     }     for (i = 0; i <= PWM_fade; i++){     //Led2 van aan naar uit; Led1 van uit naar aan;             Led1 = 0;             Led2 = 1;            Delay(PWM_fade - i);             Led1 = 1;             Led2 = 0;             Delay(i);     }  } }

The puls width frequency is always at maximum depending on your clock frequency. If you want a lower frequency for your pwm then you have to add an extra delay to Delay(). For example add Delay_us(20); between line 5 and 6.
Led2 always has the opposite duty cycle of led1 as you can see when you study the code. The value of PWM_fade determines how fast the leds are fading. This is how it looks like:

It works best when you set the value of PWM_fade via a potentiometer. All you need is an analog pin on your pic. The ADC library of MikroC makes the rest very easy.
Play with it and let me know what you find 🙂