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starfire151
Joined: 01 Apr 2007
Posts: 197
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| PWM with PIC16LF15325 |
 Posted: Thu Apr 03, 2025 9:42 am |
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I've been trying to get the PWM output to work with a PIC16LF15325 but have been unsuccessful.
From the header support file:
#pin_select PWM3=PIN_C0
#use pwm(output=PIN_C0, frequency=15625, bits=10)
From the main program:
setup_pwm3(CCP_PWM);
pwm_set_frequency(10000); // set frequency
pwm_set_duty_percent(200); // 20% duty cycle
pwm_on();
I have tried using PIN_A4 and PIN_C0 as outputs but have not been able to see the PWM output with a scope.
Is there something I'm not setting up correctly?
Thanks. |
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temtronic
Joined: 01 Jul 2010
Posts: 9446
Location: Greensville,Ontario
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| Posted: Thu Apr 03, 2025 3:51 pm |
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It seems simple, so post your program so others can copy/paste/compile/test !
'bits and pieces' don't show us the whole story....
also, does the PIC run a '1Hz LED program ' ?? |
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starfire151
Joined: 01 Apr 2007
Posts: 197
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| Posted: Thu Apr 03, 2025 4:15 pm |
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.h file:
| Code: |
#include <16LF15325.h>
#device adc=10 // 10-bit ADC => 1024 steps
#device *=16
#define clk_freq 16M
#use delay(internal=clk_freq)
#pin_select PWM3=PIN_C0
#use pwm(output=PIN_C0, frequency=15625, bits=10)
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.c file:
| Code: |
#include <pwm_16LF15325_test.h>
void main()
{
setup_timer_2(T2_DIV_BY_1, 127, 1);
setup_pwm3(CCP_PWM);
pwm_set_frequency(10000); // set frequency
pwm_set_duty_percent(200); // 20% duty cycle
while(TRUE)
{
}
}
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I also tried to use the wizard to generate a baseline program with the pwm but it was not successful, either.
Thanks for looking at it... |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19766
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| Posted: Fri Apr 04, 2025 3:28 am |
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You are 'overpecifying things'. Normally the compiler will accept this, but
I suspect this is resulting in things not working:
| Code: |
#include <16LF15325.h>
#device adc=10 // 10-bit ADC => 1024 steps
#device *=16
#define clk_freq 16M
#use delay(internal=clk_freq)
#pin_select PWM3=PIN_C0
#use pwm(PWM3, frequency=15625)
//You have already specified where PWM3 is to go.
//Also specifying 'bits', implies that the frequency may be adjusted if
//needed to give this. Just specify the frequency and the compiler will
//tell you how many bits it can achieve.
void main()
{
setup_timer_2(T2_DIV_BY_1, 127, 1);
//setup_pwm3(CCP_PWM);
//You have already setup pwm3. Don't do it again. This setup is almost
//certainly what is stopping the PWM. This is a dedicated PWM, _not_
//A CCP. CCP_PWM, is not an acceptable setting for the PWM module
//If you look at the header file, this is not listed as a parameter for
//this PWM.... You are using a command for the CCP peripheral
//on the PWM. Result disaster.......
//It'll actually turn off the enable bit for the PWM.....
//You must _never_ use command words for the wrong peripheral.
//This is exactly like putting diesel in a petrol car......
pwm_set_frequency(10000); // set frequency
pwm_set_duty_percent(200); // 20% duty cycle
while(TRUE)
{
}
}
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