WS2812_SCAN - Exercise a WS2812 LED with different timing parameters. For each set of timing parameters (j,k) the following is performed: - Wait 10µs to reset the WS2812 LED - Emit 48 pulses with the given timing Compiles with AVR-GCC for ATtiny85. LED is connected on PB1.

gistfile1.c

/*
 * WS2812_SCAN.c
 *
 * Created: 10.01.2014 20:46:20
 * Author: tim
 */ 

#include <avr/io.h>

int main(void)
{
	CLKPR=_BV(CLKPCE);		// CLKDIV=1
	CLKPR=0;
	
	DDRB|=_BV(PB1);		// Enable 0C0B/PB1
	PORTB&=~_BV(PB1);	// Set GPIO to low for the reset phase
	
	TCCR0A=0; // PWM output off
	TCCR0B=_BV(WGM02)|_BV(CS00);

    while(1) {
		uint8_t i;
		int j,k;
		_delay_ms(1); // delay before start of sequence
		for(k=4; k<64; k++)	{		
			 for (j=0; j<k ;j++) {	 
				_delay_us(10);	// Reset
				 {		
					OCR0A=k;		// Total pulse length in clockcycles
					OCR0B=j;		// "On" time in clockcycles
		 
					TCNT0=0;	
					TCCR0A=_BV(COM0B1)|_BV(WGM01)|_BV(WGM00);
			
					TIFR|=_BV(OCF0A);
					for (i=0; i<48; i++) {		// Emit 48 pulses 
						while (!(TIFR&_BV(OCF0A)));
						TIFR|=_BV(OCF0A);
					}
					TCCR0A=0;
				 }
			}
		}
	}	
}