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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| using CCP to create 1KHz signal |
 Posted: Fri Mar 17, 2006 1:31 pm |
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Hi everyone,
In the past I have used the CCP to create a 1KHZ square wave and it worked very well. On my hardware I have a socket and I changed from an 18F252 to a 18F2620 chip for more ROM/RAM. However, I now find that the 1KHz signal that used to be sent is no longer being sent.
Below is some of the pertinent code:
setup_timer_1(T1_INTERNAL);
setup_ccp1(CCP_COMPARE_RESET_TIMER);
setup_ccp2(CCP_COMPARE_INT_AND_TOGGLE);
CCP_1 = 2000;
CCP_2 = 0;
My question is why this no longer works? There is no area in my code to execute something during timer1 execution, but it was handled using the above lines. (I inherited the code from someone else). Does anyone have any idea what I can change to get this to work? Thanks!
p.s. I traced back an earlier problem I posted about to this in the hardware for those of you that saw my previous post.
Thanks! |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 17, 2006 2:29 pm |
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As I always say, post a very small test program that can be dropped
into MPLAB and compiled without errors. Post your version of the
of the compiler. |
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Tue Mar 21, 2006 6:47 am |
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Below is the code that works (generate a 1.1KHZ signal on a PIC18F252):
| Code: | #include <18F252.h>
#DEVICE *=16 ADC=10
#OPT 9
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
//#define CASCOMM // CAS communication protocol
// Set up programmer.
#FUSES HS,WDT16,PUT,BROWNOUT, PROTECT,NOLVP,NOCPD,NOWRT
// Set up M/C clock speed (used for delay loops).
#use delay (clock = 20000000)
// Specify fast I/O with all I/O pins.
#use fast_io(A)
#use fast_io(B)
#use fast_io(C)
void main ()
{
set_tris_a(0b00001111);
set_tris_b(0b00000000);
set_tris_c(0b10010000);
setup_adc_ports(RA0_RA1_ANALOG_RA3_REF); //!!!!!!!!!
//setup_adc_ports( AN0_TO_AN1 | VSS_VREF ); //!!!!!!!!!
setup_adc(ADC_CLOCK_DIV_32);
set_adc_channel(0);
setup_timer_1(T1_INTERNAL); // Divide by 1.
setup_ccp1(CCP_COMPARE_RESET_TIMER); // Set Timer1 Period
setup_ccp2(CCP_COMPARE_INT_AND_TOGGLE); // Toggle CCP2 Output
CCP_1 = 2200;
CCP_2 = 0; // Set high time limit
while(1);
} |
I then change the library to the 18F2620 and also change one line (marked with a "!!!!!!" because it wont compile on the 18F2620), and run it and NO 1.1KHZ signal is created on Pin C1. Below is the code:
| Code: | #include <18F2620.h>
#DEVICE *=16 ADC=10
#OPT 9
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
//#define CASCOMM // CAS communication protocol
// Set up programmer.
#FUSES HS,WDT16,PUT,BROWNOUT, PROTECT,NOLVP,NOCPD,NOWRT
// Set up M/C clock speed (used for delay loops).
#use delay (clock = 20000000)
// Specify fast I/O with all I/O pins.
#use fast_io(A)
#use fast_io(B)
#use fast_io(C)
void main ()
{
set_tris_a(0b00001111);
set_tris_b(0b00000000);
set_tris_c(0b10010000);
//setup_adc_ports(RA0_RA1_ANALOG_RA3_REF); //!!!!!!!!!
setup_adc_ports( AN0_TO_AN1 | VSS_VREF ); //!!!!!!!!!
setup_adc(ADC_CLOCK_DIV_32);
set_adc_channel(0);
setup_timer_1(T1_INTERNAL); // Divide by 1.
setup_ccp1(CCP_COMPARE_RESET_TIMER); // Set Timer1 Period
setup_ccp2(CCP_COMPARE_INT_AND_TOGGLE); // Toggle CCP2 Output
CCP_1 = 2200;
CCP_2 = 0; // Set high time limit
while(1);
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 21, 2006 12:37 pm |
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I tested it with PCH vs. 3.245 with an 18F452 and works. I don't have
a 18F2620 to test. The .LST file looks OK for the the 18F2620.
You didn't post your compiler version.
My suggestion is to strip the program completely down.
Turn off all the extra stuff that you had on, like the Watchdog
and code protection. Then see if it works. If it doesn't work
then post your compiler version. Example:
| Code: | #include <18F2610.h>
#fuses HS,NOWDT,PUT,BROWNOUT,NOPROTECT,NOLVP,CCP2C1
#use delay(clock=20000000)
//=================================
void main()
{
setup_timer_1(T1_INTERNAL);
setup_ccp2(CCP_COMPARE_INT_AND_TOGGLE);
CCP_2 = 0;
while(1);
}
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Tue Mar 21, 2006 1:02 pm |
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PCM,
My compiler version is 3.236. I tried the following code and it worked for 18F252 and not for 18F2620. I tried 2 different 18F2620 PIC's to see if the chip failed, but no luck. The code is below:
| Code: | #include <18F2620.h>
#FUSES HS,WDT16,PUT,BROWNOUT, PROTECT,NOLVP,NOCPD,NOWRT
#use delay (clock = 20000000)
void main ()
{
setup_timer_1(T1_INTERNAL); // Divide by 1.
setup_ccp1(CCP_COMPARE_RESET_TIMER); // Set Timer1 Period
setup_ccp2(CCP_COMPARE_INT_AND_TOGGLE); // Toggle CCP2 Output
CCP_1 = 2200;
CCP_2 = 0; // Set high time limit
while(1);
} |
When changing from the 18F252 to 18F2620 I just changed the include file to <18F2620> and nothing else. Same problem, the signal is generated using the 18F252 and not the 18F2620.
Any suggestions? |
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newguy
Joined: 24 Jun 2004
Posts: 1909
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| Posted: Tue Mar 21, 2006 1:05 pm |
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| How is the extended instruction fuse configured? Try putting NOXINST in the fuses line - I got bit by that once. |
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Tue Mar 21, 2006 1:18 pm |
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newguy,
after you suggested it, I tried it and unfortunately it did not help. If you have any further ideas though, i'd be glad to hear it.
Thanks |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 21, 2006 2:40 pm |
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The code for vs. 3.236 matches that for 3.245. I'm not sure what the
problem is. I don't have a 18F2620 to test, so I don't think I can do
any more. |
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Thu Mar 23, 2006 9:36 am |
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Does anybody have a PIC18F2620 where they could test out the code that I posted above and see if they can get the 1.1KHz signal? I"m kind of at a loss at what the problem is. Also, if anyone else has suggestions, I am more than glad to try it out.
Thanks! |
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rberek
Joined: 10 Jan 2005
Posts: 207
Location: Ottawa, Canada
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| Posted: Thu Mar 23, 2006 9:56 am |
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| If you like, I could simulate it in Proteus. However, I couldn't do that until later tonight or the weekend. I would have to compile it in version 3.242 (I think that's what I have) |
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Thu Mar 23, 2006 10:14 am |
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rberek,
I would appreciate that very much. I think version 3.242 would be fine to use it with. If you let me know the results, I would greatly appreciate it. If it comes out with a simulated 1.1KHz signal, I will give CCS a call and try to figure out whats wrong.
Thanks |
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rberek
Joined: 10 Jan 2005
Posts: 207
Location: Ottawa, Canada
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| Posted: Thu Mar 23, 2006 11:04 am |
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| OK, I'll let you know. |
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rberek
Joined: 10 Jan 2005
Posts: 207
Location: Ottawa, Canada
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| Posted: Thu Mar 23, 2006 5:21 pm |
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| Proteus is showing a 1.11 kHz signal coming out of pin12 (CCP2B) of the 18F2620, using your code. |
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jseidmann
Joined: 04 Nov 2004
Posts: 67
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| Posted: Fri Mar 24, 2006 7:49 am |
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Thank you rberek,
I am at a loss as to what the problem could be. I will e-mail the code to CCS tech support and see if they can get it working. If anyone out there has a PIC18F2620 in use and doesnt mind runing this code to see if it works, I would really appreciate it. I will also post CCS's response to my e-mail once i get it.
Thanks |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 24, 2006 11:36 am |
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Your assumption is that if the simulator shows an output, then the
problem must be in the compiler. I would think the opposite.
If it runs in the simulator, then that the problem is more likely to
be in hardware, not in the code. Here is a Proteus simulator page:
http://www.labcenter.co.uk/index.html?/products/pic16.htm
--------------------
Questions:
1. What external circuit is connected to pin C1 on your PIC ?
2. How are you measuring the signal that comes out of pin C1 ?
Are you using an oscilloscope ? |
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