DMX senden und einstellungen

#include <avr/io.h>

#include <stdint.h>

#include <avr/interrupt.h>

#include <util/delay.h>

// ********************* Definitionen *********************

uint16_t     gDmxChannel;        

uint8_t        gDmxState;

enum {BREAK, STARTB, DATA};

#define F_OSC        (20000)       //oszi 20 MHz

#define IBG           (10)        // 10 µs pause

volatile uint8_t     DmxField[50];        //array DMX 

extern void init_DMX(void);

int main(void)

{

init_DMX();

DmxField[1]= 1;                //Ausgaben

DmxField[2]= 20;        

DmxField[3]= 30;

DmxField[4]= 0;

DmxField[5]= 40;

DmxField[6]= 0;

DmxField[7]= 50;

DmxField[8]= 0;

DmxField[9]= 60;

DmxField[10]=0;

sei();

while(1);

}

void init_DMX(void)

{

//Ports zum senden TXEN

DDRD |= (1<<PD3);

PORTD |= (1<<PD3);                //Senden einschalten

//USART 250kbaud

UBRR1H  = 9;

UBRR1L  = 4;                    

//asynchron wenn UMSEL Bits = 0 

//USBS = STOP bit

//UCSZ10 8 Datenbits

UCSR1C = (1<<USBS1)|(3<<UCSZ10);                                            

UCSR1B |= (1<<TXEN1)|(1<<TXCIE1);        //TXCIE interrupt 

UDR1    = 0;

gDmxState= BREAK;                            //start USART

}

// ****************** DMX Transmission ISR ********************

ISR(USART1_TX_vect)

{

uint8_t DmxState= gDmxState;

if (DmxState == BREAK)

    {

    UBRR1H  = 0;

    UBRR1L  = (F_OSC/1600);                    //90.9kbaud    

    UDR1    = 0;                                //break senden

    gDmxState= STARTB;

    }

else if (DmxState == STARTB)

    {

    ////250kbaud, für erneutes Start bit

    UBRR1H  = 9;

    UBRR1L  = 4;            

    UDR1    = 0;            //start byte senden

    gDmxState= DATA;

    gDmxChannel= 0;

    }

else

    {

    _delay_us(IBG);

    uint16_t DmxChannel= gDmxChannel;

    UDR1 = DmxField[DmxChannel++];                //data senden

    if (DmxChannel == sizeof(DmxField)) gDmxState= BREAK; //neuer break wenn alle daten gesendet sind

    else gDmxChannel= DmxChannel;

    }

}