Re: [avr-chat] Problem with USART on AVR

[jack]

copy-paste error in main

int
main(char **argv, char argc) {
  usart_init();
  while(1) {
      usart_trx_flash("Hello, World!!\n");
  }
}

Thankx,
Jack

jack wrote:
> Thankx for the reply Hugo.
>
> The issue is resolved for now. I was using USB to serial cable on my 
> laptop and that was causing the issue (not sure how).
> I tried connecting directly to the serial port on my PC and everything 
> works fine.
>
> I have also pasted my USART code below:
>
>
> #define    F_OSC      ((unsigned long) (12*1000000))
> #define    BAUD_RATE  ((unsigned long) (19200))
> #define    MYUBRR     ((unsigned long)(F_OSC/(unsigned 
> long)(16*BAUD_RATE) - 1))
>
> void
> usart_init(void) {
>    UBRRL = (unsigned char) (MYUBRR);
>    UBRRH = (unsigned char) (MYUBRR >> 8);
>    UCSRA &= !(1<<U2X);                  // Set U2X = 0
>    UCSRB = (1<<RXEN) | (1<<TXEN);       // polling mode.
>    UCSRC = (1<<USBS) | (3<<UCSZ0);      // No parity, 8 Databit, 1 
> stop bit.
> }
>
> void
> usart_trx(char c) {
>    while (!(UCSRA & (1<<UDRE)));
>    UDR = c;
> }
>
> char
> usart_rcx(void) {
>    while (!(UCSRA & (1<<UDRE)));
>    return UDR;
> }
>
> void
> usart_trx_flash(const prog_char* str) {
>    const prog_char *p=str;
>    while (*p) {
>        usart_trx(*p);
>        p++;
>    }
> }
>
> int
> main(char **argv, char argc) {
>    while(1) {
>        usart_trx_flash("Hello, World!!\n");
>    }
> }
>
> Thankx,
> Jack
>
> Hugo González Monteverde wrote:
> > What baudrate are you using? What is the code you use for 
> > initializing UBRRH and UBRRL?
> >
> > Looks like maybe you are using a high error baudrate with your clock....
> >
> > Hugo
> >
> > jack wrote:
> > > Hi All,
> > >
> > > I am trying to run USART on ATTiny2313 at 12MHz but am seeing junk 
> > > values in between at random. Sometimes some chars in the buffer are 
> > > also skipped.
> > > It's seen more often when i am transmitting anything from SRAM 
> > > rather than FLASH.
> >
> >
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