Wireless Infrared Link

The Software
           There are two main portions of code that we are concerned with:

    -Transmitter Code
      Transmits USART Serial Data
    -Receiver Code
      Receives and Translates USART Data



           Since this circuit operates as if the transmitter and receiver were connected directly with a wire, the software has nothing out of the ordinary. The transmitter is constantly counting 0 to 8 over and over, and the receiver is parsing this input and lighting up the corresponding LEDs, over and over.

Infrared Link Transmitter Code

void main(void){
unsigned char rs232_s = '1';
OpenUSART( USART_TX_INT_OFF &
                USART_RX_INT_OFF &
                USART_ASYNCH_MODE &
                USART_EIGHT_BIT &
                USART_CONT_RX &
                USART_BRGH_HIGH,
                25 );
     while(1){
     putcUSART(rs232_s);
     Delay10KTCYx(10);
     rs232_s += 1;
     if(rs232_s == '8')
          rs232_s='0';
     }
}

           There really are no surprises here. The transmitter is setup with a routine and simple while loop that counts then transmits, then counts and then transmits over and over until infinity.

Infrared Link Receiver Code

void main(void)
{
unsigned char input;

TRISC = 0xFF;
TRISD = 0x00;

PORTD = 0x00;
OpenUSART( USART_TX_INT_OFF &
           USART_RX_INT_OFF &
           USART_ASYNCH_MODE &
           USART_EIGHT_BIT &
           USART_CONT_RX &
           USART_BRGH_HIGH,
           25 );

    while(1){
    Delay1KTCYx(1);
    input = getcUSART();
        switch(input){
            case '1' : PORTD = 0x01;
            break;
            case '2' : PORTD = 0x03;
            break;
            case '3' : PORTD = 0x07;
            break;
            case '4' : PORTD = 0x0F;
            break;
            case '5' : PORTD = 0x1F;
            break;
            case '6' : PORTD = 0x3F;
            break;
            case '7' : PORTD = 0x7F;
            break;
            case '8' : PORTD = 0xFF;
            break;
            case '0' : PORTD = 0x00;
            break;
}
    }
CloseUSART();
}

           The receiver does the same thing as the transmitter just with the opposite function: receiving. It continually checks to see if data is ready in the USART receiver buffer. When data is accepted, it is then evaluated and the LEDs updated to output the change.