Control of Stepper Motor (28BYJ-48) via its driver - used on ATMEGA-88A

main.c

/*
 * main.c - Control of Stepper Motor (28BYJ-48) via its driver
 * written for ATMEGA-88A
 *
 * Created: 16.04.2020 19:00:00
 * Author : nils
 */ 

#define F_CPU 8000000UL

#include <avr/io.h>
#include <util/delay.h>

int stepConfig[4][4] = {[0]={1,0,0,0},[1]={0,1,0,0},[2]={0,0,1,0},[3]={0,0,0,1}};


void waitStep(void){
	_delay_us(3000); // docs say min is 2ms, my experience was 2700us
}

void low(int pin){
	PORTB  &= ~(1 << pin);	
}

void high(int pin){
	PORTB  |= (1 << pin);
}

void setStepPins(int step[]){
	step[0]==1?low(PB0):high(PB0);
	step[1]==1?low(PB1):high(PB1);
	step[2]==1?low(PB2):high(PB2);
	step[3]==1?low(PB3):high(PB3);
}

void step(){
	setStepPins(stepConfig[0]);
	waitStep();	
	setStepPins(stepConfig[1]);
	waitStep();	
	setStepPins(stepConfig[2]);
	waitStep();	
	setStepPins(stepConfig[3]);
	waitStep();	
}

int main (void) {

	DDRB |= (1 << PB0);
	DDRB |= (1 << PB1);
	DDRB |= (1 << PB2);
	DDRB |= (1 << PB3);
	
	while(1) {
		step();
	}

	return 0;
}