#ifdef __AVR__ #include "../../inc/MarlinConfigPre.h" /** * get_pwm_timer * Grabs timer information and registers of the provided pin * returns Timer struct containing this information * Used by set_pwm_frequency, set_pwm_duty * */ #if ENABLED(FAST_PWM_FAN) #include "HAL.h" struct Timer { volatile uint8_t* TCCRnQ[3]; // max 3 TCCR registers per timer volatile uint16_t* OCRnQ[3]; // max 3 OCR registers per timer volatile uint16_t* ICRn; // max 1 ICR register per timer uint8_t n; // the timer number [0->5] uint8_t q; // the timer output [0->2] (A->C) }; Timer get_pwm_timer(pin_t pin) { uint8_t q = 0; switch (digitalPinToTimer(pin)) { // Protect reserved timers (TIMER0 & TIMER1) #ifdef TCCR0A #if !AVR_AT90USB1286_FAMILY case TIMER0A: #endif case TIMER0B: #endif #ifdef TCCR1A case TIMER1A: case TIMER1B: #endif break; #if defined(TCCR2) || defined(TCCR2A) #ifdef TCCR2 case TIMER2: { Timer timer = { /*TCCRnQ*/ { &TCCR2, NULL, NULL}, /*OCRnQ*/ { (uint16_t*)&OCR2, NULL, NULL}, /*ICRn*/ NULL, /*n, q*/ 2, 0 }; } #elif defined TCCR2A #if ENABLED(USE_OCR2A_AS_TOP) case TIMER2A: break; // protect TIMER2A case TIMER2B: { Timer timer = { /*TCCRnQ*/ { &TCCR2A, &TCCR2B, NULL}, /*OCRnQ*/ { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, NULL}, /*ICRn*/ NULL, /*n, q*/ 2, 1 }; return timer; } #else case TIMER2B: ++q; case TIMER2A: { Timer timer = { /*TCCRnQ*/ { &TCCR2A, &TCCR2B, NULL}, /*OCRnQ*/ { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, NULL}, /*ICRn*/ NULL, 2, q }; return timer; } #endif #endif #endif #ifdef TCCR3A case TIMER3C: ++q; case TIMER3B: ++q; case TIMER3A: { Timer timer = { /*TCCRnQ*/ { &TCCR3A, &TCCR3B, &TCCR3C}, /*OCRnQ*/ { &OCR3A, &OCR3B, &OCR3C}, /*ICRn*/ &ICR3, /*n, q*/ 3, q }; return timer; } #endif #ifdef TCCR4A case TIMER4C: ++q; case TIMER4B: ++q; case TIMER4A: { Timer timer = { /*TCCRnQ*/ { &TCCR4A, &TCCR4B, &TCCR4C}, /*OCRnQ*/ { &OCR4A, &OCR4B, &OCR4C}, /*ICRn*/ &ICR4, /*n, q*/ 4, q }; return timer; } #endif #ifdef TCCR5A case TIMER5C: ++q; case TIMER5B: ++q; case TIMER5A: { Timer timer = { /*TCCRnQ*/ { &TCCR5A, &TCCR5B, &TCCR5C}, /*OCRnQ*/ { &OCR5A, &OCR5B, &OCR5C }, /*ICRn*/ &ICR5, /*n, q*/ 5, q }; return timer; } #endif } Timer timer = { /*TCCRnQ*/ { NULL, NULL, NULL}, /*OCRnQ*/ { NULL, NULL, NULL}, /*ICRn*/ NULL, 0, 0 }; return timer; } void set_pwm_frequency(const pin_t pin, int f_desired) { Timer timer = get_pwm_timer(pin); if (timer.n == 0) return; // Don't proceed if protected timer or not recognised uint16_t size; if (timer.n == 2) size = 255; else size = 65535; uint16_t res = 255; // resolution (TOP value) uint8_t j = 0; // prescaler index uint8_t wgm = 1; // waveform generation mode // Calculating the prescaler and resolution to use to achieve closest frequency if (f_desired != 0) { int f = (F_CPU) / (2 * 1024 * size) + 1; // Initialize frequency as lowest (non-zero) achievable uint16_t prescaler[] = { 0, 1, 8, /*TIMER2 ONLY*/32, 64, /*TIMER2 ONLY*/128, 256, 1024 }; // loop over prescaler values for (uint8_t i = 1; i < 8; i++) { uint16_t res_temp_fast = 255, res_temp_phase_correct = 255; if (timer.n == 2) { // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP #if ENABLED(USE_OCR2A_AS_TOP) const uint16_t rtf = (F_CPU) / (prescaler[i] * f_desired); res_temp_fast = rtf - 1; res_temp_phase_correct = rtf / 2; #endif } else { // Skip TIMER2 specific prescalers when not TIMER2 if (i == 3 || i == 5) continue; const uint16_t rtf = (F_CPU) / (prescaler[i] * f_desired); res_temp_fast = rtf - 1; res_temp_phase_correct = rtf / 2; } LIMIT(res_temp_fast, 1u, size); LIMIT(res_temp_phase_correct, 1u, size); // Calculate frequencies of test prescaler and resolution values const int f_temp_fast = (F_CPU) / (prescaler[i] * (1 + res_temp_fast)), f_temp_phase_correct = (F_CPU) / (2 * prescaler[i] * res_temp_phase_correct), f_diff = ABS(f - f_desired), f_fast_diff = ABS(f_temp_fast - f_desired), f_phase_diff = ABS(f_temp_phase_correct - f_desired); // If FAST values are closest to desired f if (f_fast_diff < f_diff && f_fast_diff <= f_phase_diff) { // Remember this combination f = f_temp_fast; res = res_temp_fast; j = i; // Set the Wave Generation Mode to FAST PWM if (timer.n == 2) { wgm = ( #if ENABLED(USE_OCR2A_AS_TOP) WGM2_FAST_PWM_OCR2A #else WGM2_FAST_PWM #endif ); } else wgm = WGM_FAST_PWM_ICRn; } // If PHASE CORRECT values are closes to desired f else if (f_phase_diff < f_diff) { f = f_temp_phase_correct; res = res_temp_phase_correct; j = i; // Set the Wave Generation Mode to PWM PHASE CORRECT if (timer.n == 2) { wgm = ( #if ENABLED(USE_OCR2A_AS_TOP) WGM2_PWM_PC_OCR2A #else WGM2_PWM_PC #endif ); } else wgm = WGM_PWM_PC_ICRn; } } } _SET_WGMnQ(timer.TCCRnQ, wgm); _SET_CSn(timer.TCCRnQ, j); if (timer.n == 2) { #if ENABLED(USE_OCR2A_AS_TOP) _SET_OCRnQ(timer.OCRnQ, 0, res); // Set OCR2A value (TOP) = res #endif } else _SET_ICRn(timer.ICRn, res); // Set ICRn value (TOP) = res } void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) { // If v is 0 or v_size (max), digitalWrite to LOW or HIGH. // Note that digitalWrite also disables pwm output for us (sets COM bit to 0) if (v == 0) digitalWrite(pin, invert); else if (v == v_size) digitalWrite(pin, !invert); else { Timer timer = get_pwm_timer(pin); if (timer.n == 0) return; // Don't proceed if protected timer or not recognised // Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted) _SET_COMnQ(timer.TCCRnQ, (timer.q #ifdef TCCR2 + (timer.q == 2) // COM20 is on bit 4 of TCCR2, thus requires q + 1 in the macro #endif ), COM_CLEAR_SET + invert ); uint16_t top; if (timer.n == 2) { // if TIMER2 top = ( #if ENABLED(USE_OCR2A_AS_TOP) *timer.OCRnQ[0] // top = OCR2A #else 255 // top = 0xFF (max) #endif ); } else top = *timer.ICRn; // top = ICRn _SET_OCRnQ(timer.OCRnQ, timer.q, v * float(top / v_size)); // Scale 8/16-bit v to top value } } #endif // FAST_PWM_FAN #endif // __AVR__