Hey -

wondering if you see something obvious wrong with my code:

My intention - within my Receive ISR - I set a variable: comm_reception = 1; (clear it elsewhere)

I am having a problem getting into the if statement looking for comm_reception.

I placed a printf statement just before that if statement to print that value of comm_reception. - with that printf statement in the code - it works - it should that when I would send a character - comm_reception is a "1"

The printf statement is:
printf("Comm_Received = %d\n",comm_reception);

when I comment out the statement I do not get into the if statement

I don't see it -
???

Thanks
Sparky

code is below:

int main(void)
{

init_io_ports();

init_comm_port();


/* set up serial printing */
fdevopen(uart_putchar,NULL);

sei();

printf("System 2 Ready ...\n");

for(;;)
      {
        loop_counter++;

        printf("Comm_Received = %d\n",comm_reception);

        if(comm_reception == 1)
        {
printf("here\n");
        if(receive_character == '2')
        {
          printf("2 Listening\n");
            talking_to_me = 1;
            comm_reception = 0;
        }

        if(talking_to_me == 1 && receive_character == 'o')
        {
          printf("2 On\n");
            talking_to_me = 0;
            comm_reception = 0;
            talking_to_me = 0;
        }

        if(talking_to_me == 1 && receive_character == 'f')
        {
          printf("2 Off\n");
            talking_to_me = 0;
            comm_reception = 0;
            talking_to_me = 0;
        }
        if(talking_to_me == 1 && receive_character == 's')
        {
          printf("2 Status\n");
            talking_to_me = 0;
            comm_reception = 0;
            talking_to_me = 0;
        }

        }



ISR(USART_RX_vect)      //COMM RECEIVER Interrupt
{
      receive_character = UDR0;

//    if(Comm_Test_Running == 1)
//    {
            //printf("Character Received = %c\n",receive_character);
//    }

            comm_reception = 1;

            key_pressed = 1;
}

 

Please show the declaration for comm_reception. Most likly you have not declared it as volatile, so the compiler is optimising out your code because it doesn't know that it can change at a random time by the interrupt.