smart-home/weather-sensor/firmware/spi.c

#include <avr/io.h>

void SPI_Start_Transmission(volatile uint8_t *port, uint8_t pinNumber)
{
	*port &= ~(1<<pinNumber);
}

uint8_t SPI_Transfer_Byte(uint8_t byteToSend)
{
	SPDR = byteToSend;
	while(!(SPSR & (1<<SPIF))); // Wait for transmission complete
	return SPDR;
}

void SPI_Stop_Transmission(volatile uint8_t *port, uint8_t pinNumber)
{
	*port |= (1<<pinNumber); // Stop the transmission
}