matrix_1.c

/****************************************************************************

                LCD mit ATMEGA48

      Andreas Weschenfelder

      22.07.06

      Ansteuerung der 8x8 Matrix

      ueber SPI

      CS-Ansteuerung mit MAX7219 nicht moeglich

      Taktfrequenz 12Mhz

*****************************************************************************/

#include <math.h>

#include <avr/io.h>

#include <avr/delay.h>

#include <stdlib.h>

#include <avr/interrupt.h> 

#include <avr/signal.h>

#include <inttypes.h>

#include <compat/twi.h>

#include <ctype.h>

#include <string.h>

#include <avr/pgmspace.h>

#define MATRIX_DDR    DDRB  //Port an dem das Display angeschlossen wurde

#define MATRIX_PORT    PORTB

#define MATRIX_REG    PINB

#define MATRIX_LOAD    PB0

#define MATRIX_MOSI    PB3    //-> Display Data In

#define MATRIX_MISO    PB4    //Wird nicht benotigt

#define MATRIX_CLK    PB5

#define SPI_DDR      DDRB  //SPI-Port

#define SPI_PORT    PORTB

#define SPI_REG      PINB

#define SPI_MOSI    PB3    

#define SPI_MISO    PB4    

#define SPI_CLK      PB5

#define SPI_CS      PB2    // Master oder Slave-Modus

//Adressen

#define ADRESS_NO_OP    0x00

#define ADRESS_DIGIT_0    0x01    //

#define ADRESS_DIGIT_1    0x02    //

#define ADRESS_DIGIT_2    0x03    //

#define ADRESS_DIGIT_3    0x04    //

#define ADRESS_DIGIT_4    0x05    //Digitalanzeigen, gemultiplexed

#define ADRESS_DIGIT_5    0x06    //

#define ADRESS_DIGIT_6    0x07    //

#define ADRESS_DIGIT_7    0x08    //

#define ADRESS_DEC_MODE    0x09    //BCD-Wandlung

#define ADRESS_INTENSITY  0x0A    //Intensitaet Licht

#define ADRESS_SCAN_LIMIT  0x0B    //Wieviele Segemente sind angeschlossen

#define ADRESS_SHUTDOWN_MOD  0x0C    //Shut-Down-Mode  -> Stromsparmodus

#define ADRESS_DISP_TEST  0x0F    //Test-Mode

//Daten

#define DATA_SHUT_DOWN_ON  0x00

#define DATA_SHUT_DOWN_OFF  0x01

#define DATA_NO_DECODE    0x00

#define DATA_ALL_DECODE    0xFF

//Baudrate Generieren

#define    XTAL    12.0e6

#define    BAUD  9600

#define bauddivider (unsigned int)(XTAL / BAUD / 16 - 0.5)

//Prototypes-UART

void USART_Init(void);

void putchar( char c );

void puts( char *s );

//Prototypes - serielles Display

void SPI_master_init(void);

void SPI_Master_Transmit(char tmp_data);

void matrix(int tmp_adress, int tmp_data);

int main(void)

{

//UART Initialisieren

USART_Init();

//UART-Start-Ausgabe

puts( "\n\r8x8-Matrix mit MAX7219 ueber ATMEGA48 via SPI ansteuern!\n\r" );

//Initzialisierung SPI

SPI_master_init();

//LOAD muss Low sein sein - Bei Steigender Flanke wird der 16-Bit-Befehl eingelatcht

MATRIX_DDR |= (1<<MATRIX_LOAD);

MATRIX_PORT &= ~(1<<MATRIX_LOAD);

//Initialisieren des Displays

matrix(ADRESS_SHUTDOWN_MOD, DATA_SHUT_DOWN_OFF);      //Matrix aufwecken

matrix(ADRESS_DEC_MODE, DATA_NO_DECODE);          //Alle Anzeigen in BCD-Codierung

matrix(ADRESS_INTENSITY, 0x04);                //intensity    17/32

matrix(ADRESS_SCAN_LIMIT, 0x07);              //scan limit all digits

//Display aus

matrix(ADRESS_DIGIT_0, 0x00);

matrix(ADRESS_DIGIT_1, 0x00);

matrix(ADRESS_DIGIT_2, 0x00);

matrix(ADRESS_DIGIT_3, 0x00);

matrix(ADRESS_DIGIT_4, 0x00);

matrix(ADRESS_DIGIT_5, 0x00);

matrix(ADRESS_DIGIT_6, 0x00);

matrix(ADRESS_DIGIT_7, 0x00);

while(1)

  {

  }

return 0;

}

void SPI_master_init(void)

{

//MOSI, CLOCK, CS als Output, Rest als Input

SPI_DDR = (1<<SPI_MOSI)|(1<<SPI_CLK)|(1<<SPI_CS);

//Enable SPI, Master, CLK=f/16

SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);

}

void SPI_Master_Transmit(char tmp_data)

{

SPDR = tmp_data;

while(!(SPSR & (1<<SPIF)));

}

void matrix(int tmp_adress, int tmp_data)

{

MATRIX_PORT |= (1<<MATRIX_LOAD);

_delay_us(10);

SPI_Master_Transmit(tmp_adress);

SPI_Master_Transmit(tmp_data);

MATRIX_PORT &= ~(1<<MATRIX_LOAD);

MATRIX_PORT |= (1<<MATRIX_LOAD);

}

//UART_Initialisierung

void USART_Init(void)

{

UCSR0B |= (1<<RXEN0)|(1<<TXEN0);            //Enable receiver and transmitter

UCSR0C |= (3<<UCSZ00);                  // Set frame format: 8data, 1Stopbit

UBRR0H = 0x00;                      // Set baud rate => 9600 baud @ 4 MHz; Tabellenwert

UBRR0L = 75;    

}

//UART_Schreiben

void puts( char *s )

{

  while( *s )

    putchar( *s++ );

}

void putchar( char c )

{

  while( (UCSR0A & 1<<UDRE0) == 0 );

  UDR0 = c;

}