thebears/marlin_skr
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

🐛 Fix, improve PWM on AVR (#23463)

Browse Source
This commit is contained in:
Mike La Spina
2022-01-12 17:28:53 -06:00
committed by GitHub
parent 3e2a38b653
commit 2cfde39eca
7 changed files with 131 additions and 189 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
Marlin/src/HAL/AVR/HAL.cpp
View File

@@ -75,6 +75,8 @@ void HAL_init() {
#if HAS_SERVO_3
INIT_SERVO(3);
#endif
init_pwm_timers(); // Init user timers to default frequency - 1000HZ
}
void HAL_reboot() {

7
Marlin/src/HAL/AVR/HAL.h
View File

@@ -207,6 +207,7 @@ inline void HAL_adc_init() {
#define strtof strtod
#define HAL_CAN_SET_PWM_FREQ // This HAL supports PWM Frequency adjustment
#define PWM_FREQUENCY 1000 // Default PWM frequency when set_pwm_duty() is called without set_pwm_frequency()
/**
* set_pwm_frequency
@@ -226,3 +227,9 @@ void set_pwm_frequency(const pin_t pin, const uint16_t f_desired);
* Optionally allows changing the maximum size of the provided value to enable finer PWM duty control [default = 255]
*/
void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
/*
* init_pwm_timers
* sets the default frequency for timers 2-5 to 1000HZ
*/
void init_pwm_timers();

259
Marlin/src/HAL/AVR/fast_pwm.cpp
View File

@@ -21,10 +21,7 @@
*/
#ifdef __AVR__
#include "../../inc/MarlinConfigPre.h"
#include "HAL.h"
#if NEEDS_HARDWARE_PWM // Specific meta-flag for features that mandate PWM
#include "../../inc/MarlinConfig.h"
struct Timer {
volatile uint8_t* TCCRnQ[3]; // max 3 TCCR registers per timer
@@ -32,6 +29,8 @@ struct 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)
bool isPWM; // True if pin is a "hardware timer"
bool isProtected; // True if timer is protected
};
// Macros for the Timer structure
@@ -53,16 +52,13 @@ struct Timer {
#define _SET_ICRn(ICRn, V) (*(ICRn) = int(V) & 0xFFFF)
/**
* get_pwm_timer
* Get the timer information and register of the provided pin.
* Return a Timer struct containing this information.
* Used by set_pwm_frequency, set_pwm_duty
* Return a Timer struct describing a pin's timer.
*/
Timer get_pwm_timer(const pin_t pin) {
uint8_t q = 0;
switch (digitalPinToTimer(pin)) {
// Protect reserved timers (TIMER0 & TIMER1)
#ifdef TCCR0A
IF_DISABLED(AVR_AT90USB1286_FAMILY, case TIMER0A:)
case TIMER0B:
@@ -71,212 +67,147 @@ Timer get_pwm_timer(const pin_t pin) {
case TIMER1A: case TIMER1B:
#endif
break;
break; // Protect reserved timers (TIMER0 & TIMER1)
#if HAS_TCCR2
case TIMER2: {
Timer timer = {
{ &TCCR2, nullptr, nullptr },
{ (uint16_t*)&OCR2, nullptr, nullptr },
nullptr,
2, 0
};
return timer;
}
case TIMER2:
return Timer({ { &TCCR2, nullptr, nullptr }, { (uint16_t*)&OCR2, nullptr, nullptr }, nullptr, 2, 0, true, false });
#elif ENABLED(USE_OCR2A_AS_TOP)
case TIMER2A: break; // protect TIMER2A since its OCR is used by TIMER2B
case TIMER2B:
return Timer({ { &TCCR2A, &TCCR2B, nullptr }, { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, nullptr, 2, 1, true, false });
#elif defined(TCCR2A)
#if ENABLED(USE_OCR2A_AS_TOP)
case TIMER2A: break; // protect TIMER2A
case TIMER2B: {
Timer timer = {
{ &TCCR2A, &TCCR2B, nullptr },
{ (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr },
nullptr,
2, 1
};
return timer;
}
#else
case TIMER2B: ++q;
case TIMER2A: {
Timer timer = {
{ &TCCR2A, &TCCR2B, nullptr },
{ (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr },
nullptr,
2, q
};
return timer;
}
#endif
case TIMER2B: ++q; case TIMER2A:
return Timer({ { &TCCR2A, &TCCR2B, nullptr }, { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, nullptr, 2, q, true, false });
#endif
#ifdef OCR3C
case TIMER3C: ++q;
case TIMER3B: ++q;
case TIMER3A: {
Timer timer = {
{ &TCCR3A, &TCCR3B, &TCCR3C },
{ &OCR3A, &OCR3B, &OCR3C },
&ICR3,
3, q
};
return timer;
}
case TIMER3C: ++q; case TIMER3B: ++q; case TIMER3A:
return Timer({ { &TCCR3A, &TCCR3B, &TCCR3C }, { &OCR3A, &OCR3B, &OCR3C }, &ICR3, 3, q, true, false });
#elif defined(OCR3B)
case TIMER3B: ++q;
case TIMER3A: {
Timer timer = {
{ &TCCR3A, &TCCR3B, nullptr },
{ &OCR3A, &OCR3B, nullptr },
&ICR3,
3, q
};
return timer;
}
case TIMER3B: ++q; case TIMER3A:
return Timer({ { &TCCR3A, &TCCR3B, nullptr }, { &OCR3A, &OCR3B, nullptr }, &ICR3, 3, q, true, false });
#endif
#ifdef TCCR4A
case TIMER4C: ++q;
case TIMER4B: ++q;
case TIMER4A: {
Timer timer = {
{ &TCCR4A, &TCCR4B, &TCCR4C },
{ &OCR4A, &OCR4B, &OCR4C },
&ICR4,
4, q
};
return timer;
}
case TIMER4C: ++q; case TIMER4B: ++q; case TIMER4A:
return Timer({ { &TCCR4A, &TCCR4B, &TCCR4C }, { &OCR4A, &OCR4B, &OCR4C }, &ICR4, 4, q, true, false });
#endif
#ifdef TCCR5A
case TIMER5C: ++q;
case TIMER5B: ++q;
case TIMER5A: {
Timer timer = {
{ &TCCR5A, &TCCR5B, &TCCR5C },
{ &OCR5A, &OCR5B, &OCR5C },
&ICR5,
5, q
};
return timer;
}
case TIMER5C: ++q; case TIMER5B: ++q; case TIMER5A:
return Timer({ { &TCCR5A, &TCCR5B, &TCCR5C }, { &OCR5A, &OCR5B, &OCR5C }, &ICR5, 5, q, true, false });
#endif
}
Timer timer = {
{ nullptr, nullptr, nullptr },
{ nullptr, nullptr, nullptr },
nullptr,
0, 0
};
return timer;
return Timer();
}
void set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
Timer timer = get_pwm_timer(pin);
if (timer.n == 0) return; // Don't proceed if protected timer or not recognized
uint16_t size;
if (timer.n == 2) size = 255; else size = 65535;
if (timer.isProtected || !timer.isPWM) return; // Don't proceed if protected timer or not recognized
uint16_t res = 255; // resolution (TOP value)
uint8_t j = 0; // prescaler index
uint8_t wgm = 1; // waveform generation mode
const bool is_timer2 = timer.n == 2;
const uint16_t maxtop = is_timer2 ? 0xFF : 0xFFFF;
uint16_t res = 0xFF; // resolution (TOP value)
uint8_t j = CS_NONE; // prescaler index
uint8_t wgm = WGM_PWM_PC_8; // 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 };
constexpr uint16_t prescaler[] = { 1, 8, (32), 64, (128), 256, 1024 }; // (*) are Timer 2 only
uint16_t f = (F_CPU) / (2 * 1024 * maxtop) + 1; // Start with the lowest non-zero frequency achievable (1 or 31)
// loop over prescaler values
LOOP_S_L_N(i, 1, 8) {
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;
LOOP_L_N(i, COUNT(prescaler)) { // Loop through all prescaler values
const uint16_t p = prescaler[i];
uint16_t res_fast_temp, res_pc_temp;
if (is_timer2) {
#if ENABLED(USE_OCR2A_AS_TOP) // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP
const uint16_t rft = (F_CPU) / (p * f_desired);
res_fast_temp = rft - 1;
res_pc_temp = rft / 2;
#else
res_fast_temp = res_pc_temp = maxtop;
#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;
if (p == 32 || p == 128) continue; // Skip TIMER2 specific prescalers when not TIMER2
const uint16_t rft = (F_CPU) / (p * f_desired);
res_fast_temp = rft - 1;
res_pc_temp = rft / 2;
}
LIMIT(res_temp_fast, 1U, size);
LIMIT(res_temp_phase_correct, 1U, size);
LIMIT(res_fast_temp, 1U, maxtop);
LIMIT(res_pc_temp, 1U, maxtop);
// 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);
const uint32_t f_diff = _MAX(f, f_desired) - _MIN(f, f_desired),
f_fast_temp = (F_CPU) / (p * (1 + res_fast_temp)),
f_fast_diff = _MAX(f_fast_temp, f_desired) - _MIN(f_fast_temp, f_desired),
f_pc_temp = (F_CPU) / (2 * p * res_pc_temp),
f_pc_diff = _MAX(f_pc_temp, f_desired) - _MIN(f_pc_temp, 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;
if (f_fast_diff < f_diff && f_fast_diff <= f_pc_diff) { // FAST values are closest to desired f
// Set the Wave Generation Mode to FAST PWM
if (timer.n == 2)
wgm = TERN(USE_OCR2A_AS_TOP, WGM2_FAST_PWM_OCR2A, WGM2_FAST_PWM);
else
wgm = WGM_FAST_PWM_ICRn;
wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_FAST_PWM_OCR2A, WGM2_FAST_PWM)) : uint8_t(WGM_FAST_PWM_ICRn);
// Remember this combination
f = f_fast_temp; res = res_fast_temp; j = i + 1;
}
// 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;
else if (f_pc_diff < f_diff) { // PHASE CORRECT values are closes to desired f
// Set the Wave Generation Mode to PWM PHASE CORRECT
if (timer.n == 2)
wgm = TERN(USE_OCR2A_AS_TOP, WGM2_PWM_PC_OCR2A, WGM2_FAST_PWM);
else
wgm = WGM_PWM_PC_ICRn;
wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_PWM_PC_OCR2A, WGM2_PWM_PC)) : uint8_t(WGM_PWM_PC_ICRn);
f = f_pc_temp; res = res_pc_temp; j = i + 1;
}
}
}
_SET_WGMnQ(timer.TCCRnQ, wgm);
_SET_CSn(timer.TCCRnQ, j);
if (timer.n == 2) {
TERN_(USE_OCR2A_AS_TOP, _SET_OCRnQ(timer.OCRnQ, 0, res)); // Set OCR2A value (TOP) = res
if (is_timer2) {
TERN_(USE_OCR2A_AS_TOP, _SET_OCRnQ(timer.OCRnQ, 0, res)); // Set OCR2A value (TOP) = res
}
else
_SET_ICRn(timer.ICRn, res); // Set ICRn value (TOP) = res
_SET_ICRn(timer.ICRn, res); // Set ICRn value (TOP) = res
}
#endif // NEEDS_HARDWARE_PWM
void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
#if NEEDS_HARDWARE_PWM
// 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 recognized
// Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted)
_SET_COMnQ(timer.TCCRnQ, timer.q TERN_(HAS_TCCR2, + (timer.q == 2)), COM_CLEAR_SET + invert); // COM20 is on bit 4 of TCCR2, so +1 for q==2
// 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.isProtected) return; // Leave protected timer unchanged
if (timer.isPWM) {
_SET_COMnQ(timer.TCCRnQ, SUM_TERN(HAS_TCCR2, timer.q, timer.q == 2), COM_CLEAR_SET + invert); // COM20 is on bit 4 of TCCR2, so +1 for q==2
const uint16_t top = timer.n == 2 ? TERN(USE_OCR2A_AS_TOP, *timer.OCRnQ[0], 255) : *timer.ICRn;
_SET_OCRnQ(timer.OCRnQ, timer.q, uint16_t(uint32_t(v) * top / v_size)); // Scale 8/16-bit v to top value
}
else
digitalWrite(pin, v < 128 ? LOW : HIGH);
}
}
#else
void init_pwm_timers() {
// Init some timer frequencies to a default 1KHz
const pin_t pwm_pin[] = {
#ifdef __AVR_ATmega2560__
10, 5, 6, 46
#elif defined(__AVR_ATmega1280__)
12, 31
#elif defined(__AVR_ATmega644__) || defined(__AVR_ATmega1284__)
15, 6
#elif defined(__AVR_AT90USB1286__) || defined(__AVR_mega64) || defined(__AVR_mega128)
16, 24
#endif
};
analogWrite(pin, v);
UNUSED(v_size);
UNUSED(invert);
#endif
LOOP_L_N(i, COUNT(pwm_pin))
set_pwm_frequency(pwm_pin[i], 1000);
}
#endif // __AVR__

2
Marlin/src/HAL/AVR/fastio.cpp
View File

@@ -257,7 +257,7 @@ uint16_t set_pwm_frequency_hz(const_float_t hz, const float dca, const float dcb
const float pwm_top = round(count); // Get the rounded count
ICR5 = (uint16_t)pwm_top - 1; // Subtract 1 for TOP
OCR5A = pwm_top * ABS(dca); // Update and scale DCs
OCR5A = pwm_top * ABS(dca); // Update and scale DCs
OCR5B = pwm_top * ABS(dcb);
OCR5C = pwm_top * ABS(dcc);
_SET_COM(5, A, dca ? (dca < 0 ? COM_SET_CLEAR : COM_CLEAR_SET) : COM_NORMAL); // Set compare modes