I want to learn more about the shiftout function used with Arduinos and used the implementation with my ATMEGA328p.
Here is the date sheet of atmega328p
The Setup
#define F_CPU 1000000UL
#define BAUD 9600UL
#define LSBFIRST 0
#define MSBFIRST 1
#define HIGH 0x1
#define LOW 0x0
#define INPUT 0x0
#define OUTPUT 0x1
#include <avr/io.h>
#include <util/delay.h>
#include <USART.h>
#include <pinDefines.h>
#define DATA PD7
#define LATCH PB2
#define CLOCK PB0
uint8_t leds = 0;
void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
{
for (uint8_t i = 0; i < 8; ++i) {
if (bitOrder == LSBFIRST) {
PORTD |= (!!(val & (HIGH << i)) << DATA);
} else {
PORTD |= (!!(val & (HIGH << (7 - i))) << DATA);
}
PORTB |= (HIGH << clockPin);
PORTB |= (LOW << clockPin);
}
}
void updateShiftRegister() {
PORTB |= (LOW << LATCH);
shiftOut(DATA, CLOCK, LSBFIRST, leds);
PORTB |= (HIGH << LATCH);
}
void setupRegisters() {
DDRD = 0xff;
DDRB = 0xff;
}
int main(void)
{
setupRegisters();
leds = 1;
updateShiftRegister();
_delay_ms(2000);
leds = 0;
updateShiftRegister();
return (0);
}
I created an example to understand more about the function, but the outcome does not add up to what I expected to see.
Given my example, I would expect LED1 to turn on and turn off after 2sec. It turns on, but it does not turn off afterwards. Did I miss anything? I am searching for 2hrs now for the error in my code.