PCW C Compiler IDE for 16F877 Microchip

[StI2yICeR]

Hello.

I am very frustrated - I have been trying to send text through the serial port using my 16F877 microchip using the following code.
I am using the PCW C Compiler IDE to compile / load my C program onto the chip.
---

#include <16F877.h>

#fuses nowdt, hs
#device ICD=true

void delay(void);
void pause(unsigned int count);

void main() {
unsigned int i;

while (1) {
output_bit(PIN_B4, 0);
pause(4);
output_bit(PIN_B4, 1);
pause(4);

output_bit(PIN_C6, 0);
delay();
for (i=0; i<4; i++) {
output_bit(PIN_C6, 1);
delay();
output_bit(PIN_C6, 0);
delay();
}
output_bit(PIN_C6, 1);
delay();
}

}

void pause (unsigned int count){
unsigned long int i,j;
for(i=0;i<count;i++)
for (j=0;j<0xffff;j++);
}

void delay() {
setup_timer_0(RTCC_DIV_8);
set_timer0(0);
while (get_timer0() < 130);
}

---

Now the above setup assumes that the receiving end has baud 4800, parity = none, stop bits = 1, data bits = 8, flow control = none.
PIN_B4 is the LED pin (just for show) and PIN_C6 is the chip's output pin.

When the program is run, I get the following on my hyperterminal:

UUUUUUUUUWUUUUUUUUUUUUUUUUUUUUUUUUUU�UUUUU]UUUU�UUUUUUUUUUUUUUuUU]UUUUUUUUUUUUU��U�UUU�UUuUWUUUUUUUUUUUWU�UUUUUU�UUUUUUUUUUUUUUWUUUUUUUUUUUUUUUUUUUUUUUUUUUUUuUUUUUUUUUU�UUUUUUUWUUUUUUUUUUUU�UUUUUUU

From the code, I should be getting all U's, as follows:

UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU

I am not using the printf function because that results in similar mistranscriptions - I wanted to get down to the nitty-gritty basics in order to understand the problem.

I am totally lost on this one. Thank you for your time and consideration.

[PCM programmer]

You shouldn't do it that way. You should use the CCS RS-232 functions
and if you're doing a delay, use the CCS delay functions.
That's why we buy this compiler.

The key to making everything work is the #use Delay statement,
which tells the compiler your crystal frequency. From that value,
it will calculate the correct timing for everything. So if you're using
a 20 MHz crystal, then do it as shown in the example below.
If you're using the ICD, then put in the #device statement for that, too.

[StI2yICeR]

Hi. I am grateful for your help. The following is my code:

[Mark]

How are you connecting the PIC to the PC. Maybe the problem is there.

[PCM programmer]

I tested my sample program with HyperTerminal on Win98,
at 4800,N,8,1 and it works fine. It displays hundreds of "UUU"
with no problems.

I'm using a MAX232A chip for the RS-232 level conversion.

As a test, I went into Device Manager and in the Advanced section
for Com Port 1, and turned off the receive fifo. It still worked OK.

So, I think the problem could be:

1. Your crystal. Is it really running at 20 MHz ?
Are you using a crystal, or something else (resonator ?).

2. As Mark says, how are you connecting it to your PC ?
Do you have a Ground wire, going from pin 5 on the DB-9
(on the PC side) to ground on your PIC board ?

Do you have a MAX232A (or equivalent chip), and is it
putting out proper RS-232 levels ?