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wailoon86
Joined: 13 Sep 2007
Posts: 2
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| Need Help on PIC16F877A |
 Posted: Thu Sep 13, 2007 7:42 pm |
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Hello..
I am new to PIC programming. I'm currently trying to program PIC16F877A to light up an LED. Below is my code. Can someone try to advise me regarding this. Much appreciated.
#include <16F877A>
#use delay(clock=20000000)
#fuses hs,nowdt,noprotect
void main()
{
set_tris_d(0b00000000);
for(;;)
{
output_high(PIN_B0);
delay_ms(1000);
output_low(PIN_B0);
delay_ms(1000);
}
}
Is there any else that i miss? |
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misaeldv
Joined: 10 Nov 2005
Posts: 11
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| Posted: Thu Sep 13, 2007 8:49 pm |
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| What kind of problems are you facing? |
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inservi
Joined: 13 May 2007
Posts: 128
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| Posted: Fri Sep 14, 2007 4:31 am |
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Hello,
you don not need 'set_tris_d(0b00000000); '.
It is only necessary with #use fast_io (port).
dro.
_________________
in médio virtus |
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adrian
Joined: 08 Sep 2003
Posts: 92
Location: Glasgow, UK
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| Posted: Fri Sep 14, 2007 5:59 am |
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Hmm two posters with the same problem - must be homework time!
delay_ms(1000), will not work as you have found out.
You can only use delay_ms() with a 'variable' with a value of upto 255. I suggest you go and read the manual.
You can extend this value to 65535 by using a 'constant' - this is what I think you want to do.
Or you can call delay_ms(250) four times. |
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Ken Johnson
Joined: 23 Mar 2006
Posts: 197
Location: Lewisburg, WV
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| Posted: Fri Sep 14, 2007 6:29 am |
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As inservi? said, you don't need the set_tris_d. But if you do want to use fast_io, use set_tris_b if you're using pins on port b
Ken |
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inservi
Joined: 13 May 2007
Posts: 128
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| Posted: Fri Sep 14, 2007 7:02 am |
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Hello,
| Quote: | delay_ms(1000), will not work as you have found out.
You can only use delay_ms() with a 'variable' with a value of upto 255. I suggest you go and read the manual.
You can extend this value to 65535 by using a 'constant' - this is what I think you want to do.
Or you can call delay_ms(250) four times. |
I'm sorry but i often use delay_ms(1000) and it work perfectly with my PCWH as well with v3.xxx than 4.xxx.
dro.
_________________
in médio virtus |
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Foppie
Joined: 16 Sep 2005
Posts: 138
Location: The Netherlands
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| Posted: Fri Sep 14, 2007 7:31 am |
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I am not entirely ure but I think the line
| Code: | | #use delay(clock=20000000) |
must be after the fuses, so:
| Code: | #fuses hs,nowdt,noprotect
#use delay(clock=20000000) |
further I don't think the compiler should have any problems with the set_tris_d(0b00000000); line, but it's better to delete it, if only for human understanding ;)
Hope this helps,
Jos |
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inservi
Joined: 13 May 2007
Posts: 128
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| Posted: Fri Sep 14, 2007 10:27 am |
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Hello,
My last program with 16f876 (about same as 16f877) have these lines and working right:
| Code: | #use delay(clock=20000000)
#fuses NOWDT,HS, PUT, NOPROTECT, BROWNOUT, NOLVP, NOCPD, NOWRT, NODEBUG |
Foppie, | Quote: | further I don't think the compiler should have any problems with the set_tris_d(0b00000000); line, but it's better to delete it, if only for human understanding ;)
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I agree with you.
This code is working !
| Code: | void main() {
for(;;){
output_high(PIN_A2);
delay_ms(1000);
output_low(PIN_A2);
delay_ms(1000);
}
}
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wailoon86,
What kind of problems are you facing ?
Are you sure that your programmer is working right ?
Are you already programed other pic ?
dro.
_________________
in médio virtus |
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umka
Joined: 28 Aug 2007
Posts: 99
Location: New Zealand
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| Posted: Sat Sep 15, 2007 4:01 am |
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in the main routine does one not need a while(1) loop?
so use
| Code: | void main()
{
while(1)
{
output_high(PIN_A2);
delay_ms(1000);
output_low(PIN_A2);
delay_ms(1000);
}
} |
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Vodka
Joined: 13 Sep 2007
Posts: 14
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| Posted: Sat Sep 15, 2007 6:41 am |
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| everything goes well till delay_ms() apear..i have the same problem....pls tell me why??? |
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wailoon86
Joined: 13 Sep 2007
Posts: 2
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| Reply... |
| Posted: Sat Sep 15, 2007 9:19 am |
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Dear Inversi,
I also not sure whats happening with the PIC. I'm using the Cytron Programmer WINPIC800 UP00A to program it. Using the CCS C compiler, i took the .hex file and program it to the PIC.
Also, one of my colleague told me to check whether is the hardware or software problem.
Here's how I did.
output_high(PIN_B0)
output_low(PIN_B1)
:
output_high(PIN_B7)
and so on.
when i connect my multimeter, output of B5 to B3 are low.
1.And I would like to ask, must I connect pin 1 (which is Master Clear Inverted) to Vss everytime I connect the circuit?
2.I noticed certain pins have two functions. I was wondering is there a way that I can I access it?
I been reading the datasheet and CCS C Manual over and over again.
Thanks for your guys help.
Much appreciate it. |
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