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Guest
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| PCM Compiler Giving Me Junk |
 Posted: Thu Apr 21, 2005 1:22 am |
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Hi
I am a newbee. I just got my PCM compiler  . I tried the RS232 example, and had it working through RealTerm ( Hyperterminal didn't work), it displayed the status of output pin RB0 OK.
Now when I compile the code through PCM/MBLAB, all I get is junk characters. I have output this code through THREE different terminal programs, and they are all displaying junk. I tried a different program from the mikroC compiler (on the same chip, test board, programmer), and it works fine. I have set all fuses through MPLAB, and programatically.
Also, the first printf()'s don't print out properly.
This is some of the output from the terminal
Connected to COM1
Sent: 4
Received: >
Received: >0
Received: 0>
Received: >
Received: 0
Received: 0
Received: >
Received:
Received: 0
Received: 00
Received:
Received:
Received: 00
Received: 0
Received: 0
Received:
Received: 00
Received: 0
Received: 00
Received:
Received: 00
Received: 0
Received: 0
Disconnected from COM1
Here is the CCS C example code, with a couple of printf() I put in:
| Code: | /////////////////////////////////////////////////////////////////////////
//// EX_SQW.C ////
//// ////
//// This program displays a message over the RS-232 and waits for ////
//// any keypress to continue. The program will then begin a 1khz ////
//// square wave over I/O pin B0. ////
//// ////
//// Comment out the printf's and getc to eliminate the RS232 and ////
//// just output a square wave. ////
//// ////
//// Change both delay_us to delay_ms to make the frequency 1 hz. ////
//// This will be more visable on a LED. ////
//// ////
//// ////
//// This example will work with the PCB, PCM and PCH compilers. ////
//// The following conditional compilation lines are used to ////
//// include a valid device for each compiler. Change the device, ////
//// clock and RS232 pins for your hardware if needed. ////
#if defined(__PCM__)
#include <16F876A.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#elif defined(__PCB__)
#include <16C56.h>
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_A3, rcv=PIN_A2)
#elif defined(__PCH__)
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#endif
void main() {
printf("Press any key to begin\n\r");
getc();
printf("1 khz signal activated\n\r");
while (TRUE) {
printf( "Pin RB0 HIGH\n\r" );
output_high(PIN_B0);
delay_ms(500);
printf( "Pin RB0 LOW\n\r" );
output_low(PIN_B0);
delay_ms(500);
}
} |
I have searched through the archives, and have spent several hours trying to get my first program going. 
Cheers
Dale |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Apr 21, 2005 1:34 am |
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1. What PIC are you using ?
2. What is the crystal frequency ?
3. Are you using a MAX232 chip between the PIC and the PC ?
4. What baud rate is the terminal program set for ? |
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Guest
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| PCM Compiler Giving Me Junk |
| Posted: Thu Apr 21, 2005 1:48 am |
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Hi
Thanks for your reply.
Well I am using an easyPIC2 Development board from
http://www.mikroelektronika.co.yu/english/product/tools/easypic2.htm
Chip: 16F876A
XT: 8 MHz
The board uses a MAX232N, and like I said, I tried another C program using their compiler, and it worked OK.
And at one stage the CCS C example worked too.
The THREE terminal programs were all set @ 9600 bps.
With the CCS C program, all the LEDs connected to the respective ports light up or blink, including the RC7/TX when it sends a HI/LO.
Cheers
Dale |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Apr 21, 2005 2:01 am |
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The example program that you're using is set for a 20 MHz crystal.
You need to change the #use delay () statement in the section for
the 16F876A so it's set for 8 MHz. Example:
| Code: | | #use delay(clock=8000000) |
Re-compile after you make that change and see if it works. |
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Dale Stewart
Joined: 21 Apr 2005
Posts: 8
Location: Wollongong, AUSTRALIA
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| Thanks Heaps |
| Posted: Thu Apr 21, 2005 3:31 am |
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Hi PCMP
Guess what? it worked - COOL! Thanks 
Now I know why it worked before, because I must have tried 8MHz for XT. I got confused when I checked out the manual (p 61)
| Quote: | #USE DELAY
Purpose: Tells the compiler the speed of the processor... |
Maybe I am just dumb, but it seems a little ambiguous?
Once again many thanks for your help.
Cheers
Dale |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Apr 21, 2005 6:19 am |
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| Quote: | Maybe I am just dumb, but it seems a little ambiguous?
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Not at all. The compiler doesn't know the clock speed unless you tell it. It uses that value to set up the baud rate, delays and such. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu Apr 21, 2005 7:44 am |
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| Quote: | | Maybe I am just dumb, but it seems a little ambiguous? |
Yes, it is ambigious. The setting of the clock speed here is not only used for the delay functions but also for baudrate etc. This is confusing because now you expect separate directives for delay, baudrate, etc. In my opinion it would have been better to have a general '#clock' directive and forget about the #delay.
Yes, you are a little dumb. Even when you think the directive is not used in your program, because you are not calling the delay function, specifying an obvious wrong clock speed is asking for troubles. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Apr 21, 2005 7:45 am |
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| Quote: | | Yes, you are a little dumb |
Harsh |
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Guest
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| Posted: Thu Apr 21, 2005 9:02 am |
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| Clearly not that dumb, he tried the things he knew of, then rather than banging his head, he asked here. Nice to see someone thinking for themselves - don't knock that. Also he asked the right question & provided the right information leading to the answer. Dumb is those who post the one liners asking people here to do their work for them. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu Apr 21, 2005 10:04 am |
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| Sorry, no offense please. I tried to be not too serious and forgot to add the smiley. |
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Dale Stewart
Joined: 21 Apr 2005
Posts: 8
Location: Wollongong, AUSTRALIA
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| Dumby |
| Posted: Thu Apr 21, 2005 7:12 pm |
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Hi
Thankyou to everone who posted their helpful comments. I prefer to find the answer by research first by looking at the manual, search the posts, WWW, etc. Then if I am stuck its good to know there are people who are generous with their time and efforts.
(Maybe I am a little dumb  )
Cheers
Dale |
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