RS232 receive

[info@ckmintech.com]

I am using PICDEM4 for an experiment which use LT1280 for RS232 interface. on/off pin (actice high) is connected to RB3.

A simple program

#include <16f628a.h>
#fuses nowdt, hs, nolvp
#use delay(clock=8000000)
#use rs232(baud=9600,parity=N,xmit=PIN_B5,rcv=PIN_B2,bits=8)



void main()
{


output_high(PIN_B3); // enable LT1280 on/off pin
printf("Enter a char");
while (true) {

c=getc();

putc(c);
}
}

It can send "Enter a char" to a pc BUT cannot receive any data from the pc.

I double checked the cable and LT1280 and confirmed they were working fine. I also tried this porgramwith 18F1320, the result is the same.

Any idea?

Thansks

[PCM programmer]

The PicDem4 user's guide says you must have jumpers on the
upper two pins of J18 and J19. Do you have the jumpers installed ?