Prusa-Firmware/Firmware/tone04.c
Yuri D'Elia 30262b0a6e Remove redundant definitions of CRITICAL_SECTION_*
Move CRITICAL_SECTION_START/END into fastio.h, where it's needed.
2021-01-29 17:30:04 +01:00

118 lines
3.2 KiB
C

//tone04.c
// use atmega timer4 as main tone timer instead of timer2
// timer2 is used for System timer.
#include "system_timer.h"
#include "Configuration_prusa.h"
#ifdef SYSTEM_TIMER_2
#include "pins.h"
#include "fastio.h"
void timer4_init(void)
{
CRITICAL_SECTION_START;
SET_OUTPUT(BEEPER);
WRITE(BEEPER, LOW);
SET_OUTPUT(EXTRUDER_0_AUTO_FAN_PIN);
// Set timer mode 9 (PWM,Phase and Frequency Correct)
// Prescaler is CLK/1024
// Output compare is disabled on all timer pins
// Input capture is disabled
// All interrupts are disabled
TCCR4A = (1 << WGM40);
TCCR4B = (1 << WGM43) | (1 << CS42) | (1 << CS40);
OCR4A = 255;
OCR4B = 255;
OCR4C = 255;
TIMSK4 = 0;
CRITICAL_SECTION_END;
}
#ifdef EXTRUDER_0_AUTO_FAN_PIN
void timer4_set_fan0(uint8_t duty)
{
if (duty == 0 || duty == 255)
{
// We use digital logic if the duty cycle is 0% or 100%
TCCR4A &= ~(1 << COM4C1);
OCR4C = 0;
WRITE(EXTRUDER_0_AUTO_FAN_PIN, duty);
}
else
{
// Use the timer for fan speed. Enable the timer compare output and set the duty cycle.
// This function also handles the impossible scenario of a fan speed change during a Tone.
// Better be safe than sorry.
CRITICAL_SECTION_START;
// Enable the PWM output on the fan pin.
TCCR4A |= (1 << COM4C1);
OCR4C = (((uint32_t)duty) * ((uint32_t)((TIMSK4 & (1 << OCIE4A))?OCR4A:255))) / ((uint32_t)255);
CRITICAL_SECTION_END;
}
}
#endif //EXTRUDER_0_AUTO_FAN_PIN
// Because of the timer mode change, we need two interrupts. We could also try to assume that the frequency is x2
// and use a TOGGLE(), but this seems to work well enough so I left it as it is now.
ISR(TIMER4_COMPA_vect)
{
WRITE(BEEPER, 1);
}
ISR(TIMER4_OVF_vect)
{
WRITE(BEEPER, 0);
}
void tone4(__attribute__((unused)) uint8_t _pin, uint16_t frequency)
{
//this ocr and prescalarbits calculation is taken from the Arduino core and simplified for one type of timer only
uint8_t prescalarbits = 0b001;
uint32_t ocr = F_CPU / frequency / 2 - 1;
if (ocr > 0xffff)
{
ocr = F_CPU / frequency / 2 / 64 - 1;
prescalarbits = 0b011;
}
CRITICAL_SECTION_START;
// Set calcualted prescaler
TCCR4B = (TCCR4B & 0b11111000) | prescalarbits;
#ifdef EXTRUDER_0_AUTO_FAN_PIN
// Scale the fan PWM duty cycle so that it remains constant, but at the tone frequency
OCR4C = (((uint32_t)OCR4C) * ocr) / (uint32_t)((TIMSK4 & (1 << OCIE4A))?OCR4A:255);
#endif //EXTRUDER_0_AUTO_FAN_PIN
// Set calcualted ocr
OCR4A = ocr;
// Enable Output compare A interrupt and timer overflow interrupt
TIMSK4 |= (1 << OCIE4A) | (1 << TOIE4);
CRITICAL_SECTION_END;
}
void noTone4(__attribute__((unused)) uint8_t _pin)
{
CRITICAL_SECTION_START;
// Revert prescaler to CLK/1024
TCCR4B = (TCCR4B & 0b11111000) | (1 << CS42) | (1 << CS40);
#ifdef EXTRUDER_0_AUTO_FAN_PIN
// Scale the fan OCR back to the original value.
OCR4C = (((uint32_t)OCR4C) * (uint32_t)255) / (uint32_t)((TIMSK4 & (1 << OCIE4A))?OCR4A:255);
#endif //EXTRUDER_0_AUTO_FAN_PIN
OCR4A = 255;
// Disable Output compare A interrupt and timer overflow interrupt
TIMSK4 &= ~((1 << OCIE4A) | (1 << TOIE4));
CRITICAL_SECTION_END;
// Turn beeper off if it was on when noTone was called
WRITE(BEEPER, 0);
}
#endif //SYSTEM_TIMER_2