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loginatnine
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| Burned chip 16f877A with QL200 |
 Posted: Mon Oct 06, 2008 10:16 pm |
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Hi
I'm very new at programming PIC so I bought a QL200 off ebay so I could try and program some simple things in order to get better. I have a 128x64LCD with a preprogrammed hex file to use it that came with the package. I modified the program so I could use it with CCS as it was compiled with HITECH. Problem is, so far, I burned two chips while programming the 16f877a with this program and I'm wondering if I'm missing something here. The programming software I use gives me a fuse error at the end of the programming and after I can't erase/program the chip anymore. But, the chip still displays what it's supposed to on the lcd if I turn the board on.
So here is my code, is there something wrong with it?
Billion thanks
| Code: | /*Librairie LCD 128x64*/
#include <16F877A.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
void lcd_init(void);
void lcd_clear(void); //clear screen
void lcd_flash(void); //blink
void lcd_print(char*);
void send_d(int x); //send data
void send_i(int x); //send command.
void chk_busy(void);
void delay(void);
void delay1(void);
int busy;
void lcd_init(void)
{
SET_TRIS_A(0x00); //Put the IO A and D as outputs
SET_TRIS_D(0x00);
#USE STANDARD_IO (A)
output_low(PIN_A0); //reset LCD
delay();
output_high(PIN_A0);
;
output_high(PIN_A2); //8 bit as parallel.
send_i(0x30); //basic operation instruction
send_i(0x01); //display off
send_i(0x06); //set the cursor's moving direction.
send_i(0x0c); //on display,off cursor,off blink
}
void lcd_clear(void)
{
send_i(0x1); //clear all
send_i(0x34); //extend.
send_i(0x30); //basic
}
void lcd_flash(void)
{
send_i(0x08); //off display.
delay1(); //delay
send_i(0x0c); //on display
delay1();
delay1(); //delay
send_i(0x08); //off
delay1();
send_i(0x0c); //on
delay1();
delay1();
send_i(0x08); //off
delay1();
send_i(0x0c); //on
delay1();
delay1();
}
void lcd_print(char *string)
{
int i=0; //define loop count.
while(string[i]!= 0)
{
send_d(string[i]); //
delay(); //
i++; //get next.
}
}
//--------------------------------------------
//send data
void send_d(int x)
{
chk_busy(); //check busy.
output_high(PIN_A5);
output_low(PIN_A4);
OUTPUT_D(x); //data to bus.
output_high(PIN_A3);
;
;
; //enable.
output_low(PIN_A3); //disable.
}
//--------------------------------------------
//send command.
void send_i(int x)
{
chk_busy(); //check lcd if busy.
output_low(PIN_A5);
output_low(PIN_A4);
OUTPUT_D(x); //data to bus.
output_high(PIN_A3);
;
;
; //enable.
output_low(PIN_A3); //disable.
}
//-------------------------------------------
//check lcd busy.
void chk_busy()
{
busy=1; //set busy signal
SET_TRIS_D(0xFF); //change the bus to input.
output_low(PIN_A5);
output_high(PIN_A4);
while(busy)
{
;
;
;
output_high(PIN_A3);
;
;
; //enable.
if(!input(PIN_D7))
{
busy=0;
}
;
;
;
output_low(PIN_A3); //DISABLE.
}
output_low(PIN_A3); //DISABLE.
SET_TRIS_D(0x00); //bus as output.
}
//-------------------------------------------
//delay
void delay()
{
int i=0;
while(i<50)
{
i++;
}
}
//-------------------------------------------
//delay1
void delay1()
{
int i;
for(i=0;i<10;i++)
{
delay(); //call delay.
}
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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loginatnine
Guest
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| Posted: Mon Oct 06, 2008 10:31 pm |
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thanks for your quick reply
Unfortunately, I don't have another 16f877a to try the simple program but I already tried a program with the library I just posted and it worked like 10 times and after it burned the chip...
I put 20MHz as the clock thinking this was the processor speed, could that be the problem? Or could it be the different fuses I used in my code?
Thanks again |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Oct 06, 2008 10:37 pm |
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Read the link posts at the link that I posted above.
One of the comments in it is:
| Quote: |
The photograph of the board shows a 4 MHz crystal. You need to look
at your board, to what crystal it really has. |
Set the #use delay() value to the same as the crystal frequency.
Use the XT fuse for 4 MHz, and the HS fuse for 20 Mhz. |
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Guest
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| Posted: Mon Oct 06, 2008 10:49 pm |
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| PCM programmer wrote: | Read the link posts at the link that I posted above.
One of the comments in it is:
| Quote: |
The photograph of the board shows a 4 MHz crystal. You need to look
at your board, to what crystal it really has. |
Set the #use delay() value to the same as the crystal frequency. |
I read the thread and that is why I was wondering if the delay=20000000 could be a problem....I think the board has a 4MHz crystal.
| Quote: | | Use the XT fuse for 4 MHz, and the HS fuse for 20 Mhz. |
How can I do that? Do I need to put two #use delay()?
thanks |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Oct 06, 2008 10:53 pm |
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No. Look at the sample program in the link that I posted and
do it just like that.
Run the sample program instead of your program. |
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Guest
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| Posted: Mon Oct 06, 2008 10:58 pm |
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| PCM programmer wrote: | No. Look at the sample program in the link that I posted and
do it just like that.
Run the sample program instead of your program. |
Ok I'll try that as soon as I can get a new chip since this one seems dead....
thanks for your help, much appreciated! |
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loginatnine
Guest
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| Posted: Tue Oct 07, 2008 7:00 pm |
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| PCM programmer wrote: | No. Look at the sample program in the link that I posted and
do it just like that.
Run the sample program instead of your program. |
I've tried the sample program and it worked great. I've narrowed the problem I think, it's a #fuse problem. When I use the code posted earlier, the fuses are probably not right and it's making my chip not programmable afterward. But I've found a way to force erase the chip and I can program it again. And when I'm using the supplied example codes, I have no problem displaying stuff on the lcd and erase/program the chip as many times I want.
In the example source file, it's using this command :
__CONFIG(0x1832); //__CONFIG_DEBUG_OFF&_CP_ALL&_WRT_HALF&_CPD_ON&_LVP_OFF&_BODEN_OFF&_PWRTE_ON&_WDT_OFF&_HS_OS
I've not found all those fuses in the 16f877a.h file so I'm kinda lost with which one to use...
Thanks for your help |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Oct 07, 2008 7:45 pm |
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The fuses are given at the top of the 16F877A.h file:
| Code: | // Fuses:
LP, XT, HS, RC, NOWDT, WDT, NOPUT, PUT, PROTECT, DEBUG, NODEBUG
NOPROTECT, NOBROWNOUT, BROWNOUT, LVP, NOLVP, CPD, NOCPD,
WRT_50%, NOWRT, WRT_5%, WRT_25% |
You can translate them by inspection. For example, this fuse:
pretty obviously translates to:
Some other examples of how to translate them:
| Code: | _BODEN_OFF = NOBROWNOUT
_PWRTE_ON = PUT |
Your fuses have Code Protection enabled, and Flash Write Enable set to 50%. I question the need for any of that. |
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loginatnine
Joined: 07 Oct 2008
Posts: 8
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| Posted: Wed Oct 08, 2008 6:57 am |
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| PCM programmer wrote: | The fuses are given at the top of the 16F877A.h file:
| Code: | // Fuses:
LP, XT, HS, RC, NOWDT, WDT, NOPUT, PUT, PROTECT, DEBUG, NODEBUG
NOPROTECT, NOBROWNOUT, BROWNOUT, LVP, NOLVP, CPD, NOCPD,
WRT_50%, NOWRT, WRT_5%, WRT_25% |
You can translate them by inspection. For example, this fuse:
pretty obviously translates to:
Some other examples of how to translate them:
| Code: | _BODEN_OFF = NOBROWNOUT
_PWRTE_ON = PUT |
Your fuses have Code Protection enabled, and Flash Write Enable set to 50%. I question the need for any of that. |
Thanks for your help PCM
I've figured it out a little more, the problem comes from the 4MHz crystal because I have no problem when I remove the crystal when programming/erasing and putting it back afterward. Here is what the "tech support" of the ql200 said (his english is very poor):
because your hex file will RB7 pull-down for "0", can't for "1", so program error,
1. remove Y3(or J9,J10),
2. will “SUPPLY” Switch set for “OFF”
3. again will “SUPPLY” Switch set for “ON”
4. Then “Erase”/ ”Program”,
So I believe there is something wrong in my code that is making the rb7 unable to pull-up? FYI, Y3 = 4MHz crystal and J9-J10 = the jumpers that control the crystal
Do you have any idea what he meant and how I could correct it?
Thanks again |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Oct 08, 2008 12:59 pm |
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I think he is saying this:
The built-in programmer on the QL200 board can not work properly if
the PIC is already programmed to set Pin B7 to a low output level.
He gives instructions for a "work around" method to fix the problem.
- He wants you to temporarily remove the crystal (or the jumpers for the
crystal).
- Turn off the power to the board, and then turn it on.
- Program or erase the PIC.
- Turn off the power, re-install the crystal, and turn on the power.
When you follow this procedure, the existing program will not run
because there is no crystal installed. Therefore, pin B7 will not be low.
It will be set as a "floating" input. So the QL200 programmer can now
work properly.
I have a vague memory of some programmer having this same problem,
but I don't remember the details. I think they solved it by putting a
delay at the beginning of the program (100 ms or more). But I don't
know anything about the QL200 board. I think you should follow his
instructions. |
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loginatnine
Joined: 07 Oct 2008
Posts: 8
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| Posted: Wed Oct 08, 2008 6:39 pm |
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| PCM programmer wrote: | I think he is saying this:
The built-in programmer on the QL200 board can not work properly if
the PIC is already programmed to set Pin B7 to a low output level.
He gives instructions for a "work around" method to fix the problem.
- He wants you to temporarily remove the crystal (or the jumpers for the
crystal).
- Turn off the power to the board, and then turn it on.
- Program or erase the PIC.
- Turn off the power, re-install the crystal, and turn on the power.
When you follow this procedure, the existing program will not run
because there is no crystal installed. Therefore, pin B7 will not be low.
It will be set as a "floating" input. So the QL200 programmer can now
work properly.
I have a vague memory of some programmer having this same problem,
but I don't remember the details. I think they solved it by putting a
delay at the beginning of the program (100 ms or more). But I don't
know anything about the QL200 board. I think you should follow his
instructions. |
it may sound stupid and forgive me if it is, but couldn't I just program the B7 to be at high level? I'm not using this output I'm only using I/O-A and I/O-D |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Oct 08, 2008 6:44 pm |
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Or don't use pins B6 and B7. Leave them as inputs (which is the
condition they are in, after power-on reset). Let the QL200 programmer
be the only thing that uses those pins. |
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loginatnine
Joined: 07 Oct 2008
Posts: 8
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| Posted: Wed Oct 08, 2008 6:59 pm |
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| PCM programmer wrote: | Or don't use pins B6 and B7. Leave them as inputs (which is the
condition they are in, after power-on reset). Let the QL200 programmer
be the only thing that uses those pins. |
The thing is, as you can see in my code, I never use B6-B7 or set them as ouputs...And I've tried to set the Bx I/O as inputs and I got the same "Fuses" error at the end of programming....I'm lost a lil bit, if you have an idea it'd be great but I know how it can be hard debugging on a forum 
Thanks for your help pcm |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Oct 08, 2008 7:02 pm |
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I noticed that. I wondered why the support guy told you about pin B7.
I assumed that you showed him some different code. |
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