/*SPI initialization*/
void SPI_init()
{
DDRB=(1<<PCINT15)|(1<<PCINT13)|(1<<PORTB4); // set SCK, MOSI and SS as output
SPCR=(1<<SPE)|(1<<MSTR)|(1<<SPR0); // Enable SPI | set as master | SCK freq = mclk/8
set_ss(1);
// enable adc conversion
set_ss(0);
spi_tranceiver(0x94);
spi_tranceiver(0x00);
spi_tranceiver(0x00);
set_ss(1);
}
/* Single measure from the GYRO */
uint8_t single_measure(){
uint8_t res_adc1;
uint8_t res_adc2;
uint16_t angular_rate_temp = 0x0000;
uint8_t angular_rate = 0x00;
int EOC = 0;
// start command
set_ss(0);
spi_tranceiver(0x94);
spi_tranceiver(0x00);
spi_tranceiver(0x00);
set_ss(1);
// wait until EOC is set ( end of conversion )
while(!EOC){
set_ss(0);
spi_tranceiver(0x80);
res_adc1 = spi_tranceiver(0x00);
res_adc2 = spi_tranceiver(0x00);
set_ss(1);
if((res_adc1 & 0x20) == 0x20){
EOC = 1;
}
}
angular_rate_temp = (res_adc1 << 8) | res_adc2; // angular_rate = res_adc1 & res_adc2
angular_rate_temp >>= 4; // shift four bits right
angular_rate_temp &= 0x00ff; // stores the MSB 8 bits
angular_rate = angular_rate_temp;
return angular_rate;
}
void updateLeds()
{
//Start frame
spi_tranceiver(0x00);
spi_tranceiver(0x00);
spi_tranceiver(0x00);
spi_tranceiver(0x00);
//led frames
for (int i=0; i<8; i++)
{
spi_tranceiver(0xFF);
spi_tranceiver(leds[i][BLUE]);
spi_tranceiver(leds[i][GREEN]);
spi_tranceiver(leds[i][RED]);
}
//end frame
for (int i=0; i<8; i += 16)
{
spi_tranceiver(0xFF);
}
}
int main(void)
{
lcd_init(LCD_DISP_ON_CURSOR_BLINK); //Initialize LCD
spi_init_slave(); //Initialize slave SPI
unsigned char data, buffer[10];
DDRA = 0x00; //Initialize PORTA as INPUT
PORTA = 0xFF; //Enable Pull-Up Resistors
while(1)
{
lcd_clrscr(); //LCD Clear screen
lcd_home(); //LCD move cursor to home
lcd_puts("Testing");
lcd_gotoxy(0,1);
data = spi_tranceiver(ACK); //Receive data, send ACK
itoa(data, buffer, 10); //Convert integer into string
lcd_puts(buffer); //Display received data
_delay_ms(20); //Wait
}
}
