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theasus
Joined: 31 May 2009
Posts: 79
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| How can i use this command "CCP_delay" ? |
 Posted: Fri Aug 28, 2009 2:13 am |
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I want to set the "death band delay" and I have seen this command "CCP delay" on CCSC help, but I couldn't use it in my program.
These are my source codes:
| Code: |
#include <16F684.h>
#fuses XT,NOWDT,BROWNOUT,PUT,INTRC
#use delay (clock=4000000)
void main()
{
setup_ccp1(CCP_PWM_FULL_BRIDGE | CCP_PWM_H_H);
set_tris_c(0x00); // Set pins C2-C5 as outputs
setup_timer_2(T2_DIV_BY_1, 255, 1);
set_pwm1_duty(127);
while(true)
{
setup_ccp1(CCP_PWM_FULL_BRIDGE | CCP_PWM_H_H); ///////I want death band delay here////////////////
set_tris_c(0x00); // Set pins C2-C5 as outputs
setup_ccp1(CCP_PWM_FULL_BRIDGE_REV | CCP_PWM_H_H); ///////I want death band delay here////////////////
set_tris_c(0x00); // Set pins C2-C5 as outputs
}
} |
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Guest
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| Posted: Fri Aug 28, 2009 12:38 pm |
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| is there anyone to answer my question? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Aug 28, 2009 1:05 pm |
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It's not "death" band. It's dead band. This is in the PIC data sheet.
I agree that CCP_DELAY is in the compiler manual, but I can't find it
listed in any of the .h files for the PICs, so I don't think CCS implemented
it yet.
There is no CCS routine to set the dead band, so you can write one to
do it. In the program below, the set_pwm_dead_band() routine is
called after the setup_ccp1() routine. This will set the dead band time.
Also, see this post for an explanation of how to calculate the dead band
time period.
http://www.ccsinfo.com/forum/viewtopic.php?t=23896&start=1
| Code: |
#include <16F684.h>
#fuses XT,NOWDT,BROWNOUT,PUT
#use delay (clock=4000000)
void set_pwm_dead_band(int8 value)
{
int8 temp;
#byte PWM1CON = 0x16
// Put 'value' into the lower 7 bits of PWM1CON
// but don't change the top bit of PWM1CON.
value &= 0x7F;
temp = PWM1CON;
temp &= 0x80;
temp |= value;
PWM1CON = temp;
}
//=================================
void main()
{
setup_ccp1(CCP_PWM_FULL_BRIDGE | CCP_PWM_H_H);
set_pwm_dead_band(0x1F);
// Put other PWM setup code here.
while(1);
} |
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Ttelmah
Guest
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| Posted: Sat Aug 29, 2009 9:38 am |
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I think the reason it didn't appear in the setup, was that on the ECCP, it is done 'differently' from what CCS expected.
If you look at the setup commands they are all 'on/off' commands to enable a feature. The deadband delay on the ECCP, does not work like this. It is automatically enabled, when you select the half bridge mode, and not available otherwise. Hence having a 'flag' to enable it, made no sense.
What they then omitted, was a routine to program the value, when it was available....
Now, PCM, has programmed a nice routine to program the deadband, but it won't work for what the original poster wants, since he is selecting 'full bridge' operation, and the deadband is not available in this mode (and is not needed anyway, since there is no 'crossover' in the drives....
Best Wishes |
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theasus
Joined: 31 May 2009
Posts: 79
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| Posted: Mon Aug 31, 2009 1:49 am |
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| I understand from these answer for these applications (half bridge, full bridge operations..) the best way is using the associated register directly. |
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Ttelmah
Guest
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| Posted: Mon Aug 31, 2009 2:17 am |
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Yes, but it won't do anything in full bridge mode. Look at the data sheet. The dead band is _only_ available in half_bridge mode.
Best Wishes |
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