This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Serial Rx problem

I have a strange problem in my code. I cannot receive characters via the serial port.

I've read up on the TI and RI interrupts and I think I am handling these correctly.

The program goes to the serial I/O isr, but just sits at the gets(comin,4) line. When I examine comin in the watch window and input chars via the SIN = xx (where xx is an ascii code), I can see the comin array remains empty.

Below is the serial I/O interrupt routine (my application does not need Tx)

pre
void uart_rx_isr (void) interrupt 4 using 3
{ signed char index=0; EA=0;

if (RI == 1) { gets(comin,4); command = atoi(comin); } RI=FALSE; /* finished isr - clear flag */ TI=FALSE; /* TI will not be used - always clear it*/ EA=1;
}

/pre

Here is a fragment from main() - you can see that I set TI=1 initially to set the UART up

pre

TI=TRUE; /* always set TI=1 initially to allow serial printing */ RI=0;

loop: //RI=0; //IDLE

while ((1));

goto loop;
} /pre

Appreciate some pointers here.

Jason

Parents
  • I see the horribly confused yet strangely black and white 'world of Malund' continues to be nicely augmented by the fantasy world of Cpt. 'Pointless Comment' Foster.

    I suppose life wouldn't be quite so colourful without these, er, experienced developers.

    "And the lord spake unto them - the truth, in the eyes of the creators of the standard that thou hast forsaken, is that there shall be no such single entity. Strike forth all thought ye may posess of one truth and understand that all that is not false is true. And may ye also banish from thy mind any false belief that const is constant, nay it is as fickle as a lady who giveth her address without resistance" - and so on.

Reply
  • I see the horribly confused yet strangely black and white 'world of Malund' continues to be nicely augmented by the fantasy world of Cpt. 'Pointless Comment' Foster.

    I suppose life wouldn't be quite so colourful without these, er, experienced developers.

    "And the lord spake unto them - the truth, in the eyes of the creators of the standard that thou hast forsaken, is that there shall be no such single entity. Strike forth all thought ye may posess of one truth and understand that all that is not false is true. And may ye also banish from thy mind any false belief that const is constant, nay it is as fickle as a lady who giveth her address without resistance" - and so on.

Children