[avr-libc-dev] Atmega2560

[david]

I have a atmega2560 with the stk500 w/ 503 adapter.

I'm trying to get something to work.

I've produced a simple program - one that reads the
switches and lights the opposite LED (i.e pressing
switch 7 lights LED 0, pressing switch 7 lights LED 1,
etc) .  It also prints out the switch number that was
pressed.

I developed the original program on an atmega128.  It
appears to work fine on that target.  I realize that
just because a program runs - doesn't mean it is
correct - I could have errors in my code.

For the atmega2560, I compiled the program for the
atmega128, but replaced the iom128.h file with one for
the atmega1280.  I avoided passing parameters on the
stack - in fact I only call a single procedure - the
one to transmit a byte to the uart.  My transmit
routine polls - I use no interrupts - so I should not
have to worry about having an incorrect interrupt
vector table.

My code appears to run.  The LEDs light when the
switches are pressed.  I get output from the UART -
but it is garbage characters (periods as viewed from a
minicom window).  I don't think I have a problem with
the baudrate calculation verses the fuse bits
settings.  I have fusebits set up use an external
clock and use the clock on the stk500 (same as I do
with the atmega128).

Can anyone point out what I am doing wrong?

Any suggestions and wisdom will be appreciated.  My
goal is to eventually get a working setup with an
atmega2560 using gcc and avrlibc.  I am taking baby
steps.

dave


#ifndef UCSZ0
#define UCSZ0 UCSZ00
#define RXC RXC0
#define UDRE UDRE0
#endif

#include <avr/io.h>        // I/O definitions (port
names, pin names, etc)

#ifndef BV
        #define BV(bit)                 (1<<(bit))
#endif

#ifndef cbi
        #define cbi(reg,bit)    reg &= ~(BV(bit))
#endif
#ifndef sbi
        #define sbi(reg,bit)    reg |= (BV(bit))
#endif

typedef unsigned long  u32;
typedef unsigned char  u08;

// CPU clock speed
//#define F_CPU        16000000                         //
16MHz processor
//#define F_CPU        14745000                         //
14.745MHz processor
//#define F_CPU        8000000                          // 8MHz
processor
//#define F_CPU        7372800                          //
7.37MHz processor
//#define F_CPU        4000000                          // 4MHz
processor
#define F_CPU        3686400                            //
3.69MHz processor
#define CYCLES_PER_US ((F_CPU+500000)/1000000)  // cpu
cycles per microsecond

#define SW0()               ((PINA >> 0) & 1)
#define SW1()               ((PINA >> 1) & 1)
#define SW2()               ((PINA >> 2) & 1)
#define SW3()               ((PINA >> 3) & 1)
#define SW4()               ((PINA >> 4) & 1)
#define SW5()               ((PINA >> 5) & 1)
#define SW6()               ((PINA >> 6) & 1)
#define SW7()               ((PINA >> 7) & 1)

#define SET_LED0()          cbi(PORTB,0)
#define SET_LED1()          cbi(PORTB,1)
#define SET_LED2()          cbi(PORTB,2)
#define SET_LED3()          cbi(PORTB,3)
#define SET_LED4()          cbi(PORTB,4)
#define SET_LED5()          cbi(PORTB,5)
#define SET_LED6()          cbi(PORTB,6)
#define SET_LED7()          cbi(PORTB,7)

#define CLR_LED0()          sbi(PORTB,0)
#define CLR_LED1()          sbi(PORTB,1)
#define CLR_LED2()          sbi(PORTB,2)
#define CLR_LED3()          sbi(PORTB,3)
#define CLR_LED4()          sbi(PORTB,4)
#define CLR_LED5()          sbi(PORTB,5)
#define CLR_LED6()          sbi(PORTB,6)
#define CLR_LED7()          sbi(PORTB,7)

#define SWITCH_ON 0
#define SWITCH_OFF  1



/* Initialize UART */
u32 baudrate;
u08 baudrateDiv;
void InitUART( )
{

     baudrate = 9600;
     baudrateDiv =
(u08)((F_CPU+(baudrate*8L))/(baudrate*16L)-1);
  
     UBRR0H = baudrateDiv >> 8;
     UBRR0L = baudrateDiv;

     UCSR0B = (1 << RXEN0) | (1<<TXEN0);

     UCSR0C = (3<<UCSZ0);
}


unsigned char data;
void transmitByte( )
{

   while (!(UCSR0A & (1<<UDRE)))
    ;
   UDR0 = data;

   data = 'A';
   while (!(UCSR0A & (1<<UDRE)))
    ;
   UDR0 = 0xa;

   data = 'A';
   while (!(UCSR0A & (1<<UDRE)))
    ;
   UDR0 = 0xd;
}

int main(void)
{

   /* Setup Digital IO */
   DDRA = 0x00;  /* Port a (all pins) is input  */
   DDRB = 0xFF;  /* Port c (all pins) is output */
   PORTB = 0xFF;

   InitUART();
   data = 'A';
   transmitByte();


while(1)
   {

      if (SW0() == SWITCH_ON)
      {
         data = '0';
         transmitByte();
         SET_LED7();
      }
      else
         CLR_LED7();

      if (SW1() == SWITCH_ON)
      {
         data = '1';
         transmitByte();
         SET_LED6();
      }
      else
         CLR_LED6();

      if (SW2() == SWITCH_ON)
      {
         data = '2';
         transmitByte();
         SET_LED5();
      }
      else
         CLR_LED5();

      if (SW3() == SWITCH_ON)
      {
         data = '3';
         transmitByte();
         SET_LED4();
      }
      else
         CLR_LED4();

      if (SW4() == SWITCH_ON)
      {
         data = '4';
         transmitByte();
         SET_LED3();
      }
      else
         CLR_LED3();

      if (SW5() == SWITCH_ON)
      {
         data = '5';
         transmitByte();
         SET_LED2();
      }
      else
         CLR_LED2();

      if (SW6() == SWITCH_ON)
      {
         data = '6';
         transmitByte();
         SET_LED1();
      }
      else
         CLR_LED1();

      if (SW7() == SWITCH_ON)
      {
         data = '7';
         transmitByte();
         SET_LED0();
      }
      else
         CLR_LED0();

   }

}



                
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