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Reduced PWM frequency till ~ 1 kHz

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master
maxxir 7 years ago
parent 8477a377ea
commit 8f5fa0a833
2 changed files with 15 additions and 68 deletions
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41
19_m1284p_WIZNET_blynk/main.c
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@ -269,7 +269,7 @@ void pwm8bit_timer2_init(void)
{
//PWM on TIMER2 (PD7/OC2A) && TIMER2 (PD6/OC2B)
// PHASE CORRECT PWM 8-bit mode setup
// 31.25kHz FREQ OUT
// 31.25kHz FREQ OUT / 0.98kHz FREQ OUT
// Set PD7 to OUT
DDRD |= (1<<7);
@ -291,41 +291,15 @@ void pwm8bit_timer2_init(void)
/*
* clkI/O/1 (No prescaling)
*/
TCCR2B = (1<<CS20); // 16Mhz input
//TCCR2B = (1<<CS20); // 16Mhz input
OCR2A = 0x0;// SET output duty cycle OCR2A 0%
OCR2B = 0x0;// SET output duty cycle OCR2B 0%
}
void pwm8bitfast_timer2_init(void)
{
//PWM on TIMER2 (PD7/OC2A) && (PD6/OC2B )
// FAST PWM 8-bit mode setup
// 62.5kHz FREQ OUT
// Set PD7 to OUT
DDRD |= (1<<7);
// Set PD6 to OUT
DDRD |= (1<<6);
/*
* Compare Output Mode, Fast PWM
* Clear OCnA/OCnB/OCnC on compare match,
* Set OCnA/OCnB/OCnC at TOP
* clkI/O/32 (1:32 prescaling)
*/
TCCR2A = (1<<COM2A1)|(1<<COM2B1);
/*
* FAST PWM 8-bit
*/
TCCR2A |= (1<<WGM21)|(1<<WGM20);
/*
* clkI/O/1 (No prescaling)
*/
TCCR2B = (1<<CS20); // 16Mhz input
TCCR2B = (1<<CS21)|(1<<CS20); // 16Mhz input / 32
OCR2A = 0x0;// SET output OCR2A duty cycle 0%
OCR2B = 0x0;// SET output OCR2B duty cycle 0%
OCR2A = 0x0;// SET output duty cycle OCR2A 0%
OCR2B = 0x0;// SET output duty cycle OCR2B 0%
}
//*********************************Timer2 PWM: END
@ -597,8 +571,7 @@ static void avr_init(void)
sw1_conf();//SW1 internal pull-up
//pwm8bitfast_timer2_init(); // PD7/OC2A used as FAST 8bit PWM (62.5kHz FREQ OUT)
pwm8bit_timer2_init(); // PD7/OC2A used as PHASE CORRECT 8bit PWM (31.25kHz FREQ OUT)
pwm8bit_timer2_init(); // PD7/OC2A used as PHASE CORRECT 8bit PWM (0.98kHz FREQ OUT)
sei(); //re-enable global interrupts

42
20_m1284p_BTLD_WIZNET_BLYNK_FTPD_FATFS_SDCARD/main.c
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@ -295,7 +295,7 @@ void pwm8bit_timer2_init(void)
{
//PWM on TIMER2 (PD7/OC2A) && TIMER2 (PD6/OC2B)
// PHASE CORRECT PWM 8-bit mode setup
// 31.25kHz FREQ OUT
// 31.25kHz FREQ OUT / 0.98kHz FREQ OUT
// Set PD7 to OUT
DDRD |= (1<<7);
@ -317,42 +317,17 @@ void pwm8bit_timer2_init(void)
/*
* clkI/O/1 (No prescaling)
*/
TCCR2B = (1<<CS20); // 16Mhz input
//TCCR2B = (1<<CS20); // 16Mhz input
OCR2A = 0x0;// SET output duty cycle OCR2A 0%
OCR2B = 0x0;// SET output duty cycle OCR2B 0%
}
void pwm8bitfast_timer2_init(void)
{
//PWM on TIMER2 (PD7/OC2A) && (PD6/OC2B )
// FAST PWM 8-bit mode setup
// 62.5kHz FREQ OUT
// Set PD7 to OUT
DDRD |= (1<<7);
// Set PD6 to OUT
DDRD |= (1<<6);
/*
* Compare Output Mode, Fast PWM
* Clear OCnA/OCnB/OCnC on compare match,
* Set OCnA/OCnB/OCnC at TOP
* clkI/O/32 (1:32 prescaling)
*/
TCCR2A = (1<<COM2A1)|(1<<COM2B1);
TCCR2B = (1<<CS21)|(1<<CS20); // 16Mhz input / 32
/*
* FAST PWM 8-bit
*/
TCCR2A |= (1<<WGM21)|(1<<WGM20);
/*
* clkI/O/1 (No prescaling)
*/
TCCR2B = (1<<CS20); // 16Mhz input
OCR2A = 0x0;// SET output OCR2A duty cycle 0%
OCR2B = 0x0;// SET output OCR2B duty cycle 0%
OCR2A = 0x0;// SET output duty cycle OCR2A 0%
OCR2B = 0x0;// SET output duty cycle OCR2B 0%
}
//*********************************Timer2 PWM: END
@ -937,8 +912,7 @@ static void avr_init(void)
sw1_conf();//SW1 internal pull-up
//pwm8bitfast_timer2_init(); // PD7/OC2A used as FAST 8bit PWM (62.5kHz FREQ OUT)
pwm8bit_timer2_init(); // PD7/OC2A used as PHASE CORRECT 8bit PWM (31.25kHz FREQ OUT)
pwm8bit_timer2_init(); // PD7/OC2A used as PHASE CORRECT 8bit PWM (0.98kHz FREQ OUT)
sei(); //re-enable global interrupts