USART Trigger not working

Question

I've been trying to debug this program. I am using an ATmega328p My USART trigger isn't getting called? Maybe I'm missing something?

Hardware using PuTTY to send message or simply echo 1> COM1

#include <avr/io.h>

#include <avr/interrupt.h>

#include <util/setbaud.h>

#ifndef BAUD

#define BAUD 9600

#endif

int main(void) {

DDRB = 0x1;

UCSR0B = (1 << TXEN0) | (1 << RXEN0) | ( 1 << RXCIE0 );

UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);

UBRR0H = UBRRH_VALUE;

UBRR0L = UBRRL_VALUE;

sei( );

while (1) { }

return (0);

}

ISR( USART_RX_vect ) {

PORTB ^= 0x1;

}

Robert Peter Oakes · Accepted Answer

OK, i did not look there so its good you have that covered

one thought on the re-trigger is reading from the port in some way once the trigger has occured so that it will reset the trigger. without searching through the data sheets, it is often the case that the recieved charcter will trigger the interupt but at this point further triggers are dissabled untill the character is read from the buffer

USART Trigger not working

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