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PWM ansteuerbar und TOP wird returned

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This commit is contained in:
Tristan Krause 2019-05-28 12:32:31 +02:00
parent 1f53117577
commit 2c47159df3
78 changed files with 459 additions and 148 deletions
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30
firmware/pwm.cpp
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@ -1,18 +1,32 @@
#include "pwm.h"
const uint16_t PWM::PRESCALERS[] = {0, 1, 8, 64, 256, 1024};
const uint8_t PWM::PRESCALER_COUNT = sizeof(PRESCALERS) / sizeof(uint16_t);
void pwmSetFrequency(uint32_t freq)
void PWM::init() const volatile
{
// fast pwm mode, top = OCR0A, non inverting mode
TCCR0A = _BV(COM0B1) | _BV(WGM00) | _BV(WGM01);
DDRB |= _BV(PB4);
TCCR0B = _BV(WGM02);
uint16_t p_ideal = ceil(float(F_CPU) / (freq * 0x100));
for(int8_t i = PWM_PRESCALER_COUNT - 1; i >= 0 && PWM_PRESCALERS[i] >= p_ideal; i--)
TCCR0B = _BV(WGM02) | i; // set prescaler
if(p_ideal)
OCR0A = (uint8_t) (float(F_CPU) / (freq * PWM_PRESCALERS[TCCR0B & 0x07]));
// output signal on PB4
DDRB |= _BV(PB4);
}
void pwmSetValue(uint8_t value)
void PWM::setFrequency(uint32_t freq) const volatile
{
uint16_t p_ideal = ceil(float(F_CPU) / (freq * 0x100));
for(int8_t i = PRESCALER_COUNT - 1; i >= 0 && PRESCALERS[i] >= p_ideal; i--)
TCCR0B = (TCCR0B & 0xF8) | i; // set prescaler
if(p_ideal)
OCR0A = (uint8_t) (float(F_CPU) / (freq * PRESCALERS[TCCR0B & 0x07]));
}
void PWM::setValue(uint8_t value) const volatile
{
OCR0B = value;
}
uint8_t PWM::getTop() const volatile
{
return OCR0A;
}