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Oct 14, 2025
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ESP32: improve PWM driver fast funcrtions #492

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100 changes: 50 additions & 50 deletions src/drivers/hardware_specific/esp32/esp32_driver_mcpwm.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@
* 6 PWM independent signals per unit
* unit(0/1) > timer(0-2) > operator(0-2) > comparator(0-1) > generator(0-1) > pwm(A/B)
*
* -------------------------------------- Table View -----------------------------
* -------------------------------------- Table View -----------------------------
*
* group | timer | operator | comparator | generator | pwm
* --------------------------------------------------------------------------------
Expand All @@ -28,31 +28,31 @@
* ------------------------------------- Example 3PWM ------------------------------
* ┌─ comparator 0 - generator 0 -> pwm A
* ┌─ operator 0 -|
* | └─ comparator 1 - generator 1 -> pmw B
* | └─ comparator 1 - generator 1 -> pmw B
* unit - timer 0-2 -|
* 0-1 └─ operator 1 - comparator 0 - generator 0 - pwm C
*
*
* ------------------------------------- Example 2PWM ------------------------------
* ┌─ comparator 0 - generator 0 -> pwm A
* unit - timer 0-2 - operator 0 -|
* 0-1 └─ comparator 1 - generator 1 -> pmw B
* 0-1 └─ comparator 1 - generator 1 -> pmw B
*
* -------------------------------------- Example 4PWM -----------------------------
* -------------------------------------- Example 4PWM -----------------------------
* ┌─ comparator 0 - generator 0 -> pwm A
* ┌─ operator 0 -|
* | └─ comparator 1 - generator 1 -> pmw B
* unit - timer 0-2 -|
* | └─ comparator 1 - generator 1 -> pmw B
* unit - timer 0-2 -|
* 0-1 | ┌─ comparator 0 - generator 0 -> pwm C
* └─ operator 1 -|
* └─ comparator 0 - generator 0 -> pwm D
* └─ comparator 0 - generator 0 -> pwm D


* Complementary mode
* ------------------
* - : 3 pairs of complementary PWM signals per unit
* unit(0/1) > timer(0) > operator(0-2) > comparator(0-1) > generator(0-1) > pwm(high/low pair)
*
* -------------------------------------- Table View -----------------------------
*
* -------------------------------------- Table View -----------------------------
*
* group | timer | operator | comparator | generator | pwm
* ------------------------------------------------------------------------
Expand All @@ -63,26 +63,26 @@
* 0-1 | 0 | 2 | 0 | 0 | A
* 0-1 | 0 | 2 | 1 | 1 | B
*
* -------------------------------------- Example 6PWM -----------------------------
*
* -------------------------------------- Example 6PWM -----------------------------
*
* ┌─ comparator 0 - generator 0 -> pwm A_h
* ┌─ operator 0 -|
* ┌─ operator 0 -|
* | └─ comparator 1 - generator 1 -> pmw A_l
* |
* |
* unit | ┌─ comparator 0 - generator 0 -> pwm B_h
* (group) - timer 0 -|- operator 1 -|
* 0-1 | └─ comparator 1 - generator 1 -> pmw B_l
* |
* | ┌─ comparator 0 - generator 0 -> pwm C_h
* └─ operator 2 -|
* └─ comparator 1 - generator 1 -> pmw C_l
*
*


* More info
* ----------
* - timers can be associated with any operator, and multiple operators can be associated with the same timer
* - comparators can be associated with any operator
* - comparators can be associated with any operator
* - two comparators per operator for independent mode
* - one comparator per operator for complementary mode
* - generators can be associated with any comparator
Expand All @@ -96,7 +96,7 @@
* and here: // https://docs.espressif.com/projects/esp-idf/en/v5.1.4/esp32/migration-guides/release-5.x/5.0/peripherals.html
*/

#include "../../hardware_api.h"
#include "../../hardware_api.h"

#if defined(ESP_H) && defined(ARDUINO_ARCH_ESP32) && defined(SOC_MCPWM_SUPPORTED) && !defined(SIMPLEFOC_ESP32_USELEDC)

Expand All @@ -114,7 +114,7 @@

// MCPWM driver hardware timer pointers
mcpwm_timer_handle_t timers[2][3] = {NULL};
// MCPWM timer periods configured (directly related to the pwm frequency)
// MCPWM timer periods configured (directly related to the pwm frequency)
uint32_t pwm_periods[2][3];
// how many pins from the groups 6 pins is used
uint8_t group_pins_used[2] = {0};
Expand Down Expand Up @@ -143,7 +143,7 @@ uint8_t _findLastTimer(int group){
// return the last index
return i;
}
// returns the index of the next timer to instantiate
// returns the index of the next timer to instantiate
// -1 if no timers available
uint8_t _findNextTimer(int group){
int i = 0;
Expand All @@ -157,7 +157,7 @@ uint8_t _findNextTimer(int group){

/*
* find the best group for the pins
* if 6pwm
* if 6pwm
* - Only option is an an empty group
* if 3pwm
* - Best is an empty group (we can set a pwm frequency)
Expand All @@ -180,11 +180,11 @@ uint8_t _findNextTimer(int group){
* For example if the group has already used 3pwms, there is one generator that has one pwm channel left.
* If we use this channel we have to use the same timer it has been used with before, so we cannot change the pwm frequency.
* Current implementation does use the remaining channel only if there isn't other options that would allow changing the pwm frequency.
* In this example where we have 3pwms already configured, if we try to configure 2pws after, we will skip the remaining channel
* In this example where we have 3pwms already configured, if we try to configure 2pws after, we will skip the remaining channel
* and use a new timer and operator to allow changing the pwm frequency. In such cases we loose (cannot be used) the remaining channel.
* TODO: use the pwm_frequency to avoid skipping pwm channels !
*
* returns
* returns
* - 1 if solution found in one group
* - 2 if solution requires using both groups
* - 0 if no solution possible
Expand All @@ -199,13 +199,13 @@ int _findBestGroup(int no_pins, long pwm_freq, int* group, int* timer){
}
}

// if 3 or 1pwm
// if 3 or 1pwm
// check if there is available space in one of the groups
// otherwise fail
if(no_pins == 3 || no_pins==1){
// second best option is if there is a group with
// pair number of pwms available as we can then
// set the pwm frequency
// second best option is if there is a group with
// pair number of pwms available as we can then
// set the pwm frequency
for(int i=0; i<SOC_MCPWM_GROUPS; i++){
if(_hasAvailablePins(i, no_pins+1)) {
*group=i;
Expand Down Expand Up @@ -284,13 +284,13 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
.pwm_frequency = pwm_frequency,
.group_id = mcpwm_group
};

mcpwm_timer_config_t pwm_config;
pwm_config.group_id = mcpwm_group;
pwm_config.clk_src = MCPWM_TIMER_CLK_SRC_DEFAULT;
pwm_config.resolution_hz = _PWM_TIMEBASE_RESOLUTION_HZ;
pwm_config.count_mode = MCPWM_TIMER_COUNT_MODE_UP_DOWN;
pwm_config.intr_priority = 0;
pwm_config.count_mode = MCPWM_TIMER_COUNT_MODE_UP_DOWN;
pwm_config.intr_priority = 0;
pwm_config.period_ticks = _calcPWMPeriod(pwm_frequency);
#ifdef ESP_IDF_VERSION_ABOVE_5_4_0
pwm_config.flags.allow_pd = 0;
Expand All @@ -302,7 +302,7 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
params->mcpwm_period = pwm_periods[mcpwm_group][timer_no];

uint8_t no_operators = 3; // use 3 comparators one per pair of pwms
SIMPLEFOC_ESP32_DRV_DEBUG("Configuring " + String(no_operators) + " operators.");
SIMPLEFOC_ESP32_DRV_DEBUG("Configuring " + String(no_operators) + " operators.");
mcpwm_operator_config_t operator_config = { .group_id = mcpwm_group };
operator_config.intr_priority = 0;
operator_config.flags.update_gen_action_on_tep = true;
Expand All @@ -313,9 +313,9 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
}

#if SIMPLEFOC_ESP32_HW_DEADTIME == true // hardware dead-time (hardware 6pwm)

SIMPLEFOC_ESP32_DRV_DEBUG("Configuring 6PWM with hardware dead-time");

SIMPLEFOC_ESP32_DRV_DEBUG("Configuring " + String(no_operators) + " comparators.");
// Create and configure comparators
mcpwm_comparator_config_t comparator_config = {0};
Expand All @@ -324,7 +324,7 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
CHECK_ERR(mcpwm_new_comparator(params->oper[i], &comparator_config, &params->comparator[i]),"Could not create comparator: " + String(i));
CHECK_ERR(mcpwm_comparator_set_compare_value(params->comparator[i], (0)), "Could not set duty on comparator: " + String(i));
}

#else // software dead-time (software 6pwm)
// software dead-time (software 6pwm)
SIMPLEFOC_ESP32_DRV_DEBUG("Configuring 6PWM with software dead-time");
Expand All @@ -339,7 +339,7 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
CHECK_ERR(mcpwm_new_comparator(params->oper[oper_index], &comparator_config, &params->comparator[i]),"Could not create comparator: " + String(i));
CHECK_ERR(mcpwm_comparator_set_compare_value(params->comparator[i], (0)), "Could not set duty on comparator: " + String(i));
}
#endif
#endif

int no_generators = 6; // one per pwm
SIMPLEFOC_ESP32_DRV_DEBUG("Configuring " + String(no_generators) + " generators.");
Expand All @@ -355,9 +355,9 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,

#if SIMPLEFOC_ESP32_HW_DEADTIME == true // hardware dead-time (hardware 6pwm)
for (int i = 0; i < no_operators; i++) {
CHECK_ERR(_configureCenterAlign(params->generator[2*i],params->comparator[i]), "Failed to configure high-side center align pwm: " + String(2*i));
CHECK_ERR(_configureCenterAlign(params->generator[2*i+1],params->comparator[i]), "Failed to configure low-side center align pwm: " + String(2*i+1));
CHECK_ERR(_configureCenterAlign(params->generator[2*i],params->comparator[i]), "Failed to configure high-side center align pwm: " + String(2*i));
CHECK_ERR(_configureCenterAlign(params->generator[2*i+1],params->comparator[i]), "Failed to configure low-side center align pwm: " + String(2*i+1));

}
// only available for 6pwm
SIMPLEFOC_ESP32_DRV_DEBUG("Configuring dead-time.");
Expand All @@ -369,15 +369,15 @@ void* _configure6PWMPinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no,
mcpwm_dead_time_config_t dt_config_low;
dt_config_low.posedge_delay_ticks = 0;
dt_config_low.negedge_delay_ticks = dead_time;
dt_config_low.flags.invert_output = SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH;
dt_config_low.flags.invert_output = SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH;
for (int i = 0; i < no_operators; i++) {
CHECK_ERR(mcpwm_generator_set_dead_time(params->generator[2*i], params->generator[2*i], &dt_config_high),"Could not set dead time for generator: " + String(i));
CHECK_ERR(mcpwm_generator_set_dead_time(params->generator[2*i+1], params->generator[2*i+1], &dt_config_low),"Could not set dead time for generator: " + String(i+1));
}
#else // software dead-time (software 6pwm)
for (int i = 0; i < 3; i++) {
CHECK_ERR(_configureCenterAlign(params->generator[2*i],params->comparator[2*i], !SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH), "Failed to configure high-side center align pwm: " + String(2*i));
CHECK_ERR(_configureCenterAlign(params->generator[2*i+1],params->comparator[2*i+1], SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH) , "Failed to configure low-side center align pwm: " + String(2*i+1));
CHECK_ERR(_configureCenterAlign(params->generator[2*i],params->comparator[2*i], !SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH), "Failed to configure high-side center align pwm: " + String(2*i));
CHECK_ERR(_configureCenterAlign(params->generator[2*i+1],params->comparator[2*i+1], SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH) , "Failed to configure low-side center align pwm: " + String(2*i+1));
}
#endif

Expand Down Expand Up @@ -412,16 +412,16 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
.pwm_frequency = pwm_frequency,
.group_id = mcpwm_group
};

bool shared_timer = false;
// check if timer is configured
if (timers[mcpwm_group][timer_no] == NULL){
mcpwm_timer_config_t pwm_config;
pwm_config.group_id = mcpwm_group;
pwm_config.clk_src = MCPWM_TIMER_CLK_SRC_DEFAULT;
pwm_config.resolution_hz = _PWM_TIMEBASE_RESOLUTION_HZ;
pwm_config.count_mode = MCPWM_TIMER_COUNT_MODE_UP_DOWN;
pwm_config.intr_priority = 0;
pwm_config.count_mode = MCPWM_TIMER_COUNT_MODE_UP_DOWN;
pwm_config.intr_priority = 0;
pwm_config.period_ticks = _calcPWMPeriod(pwm_frequency);
#ifdef ESP_IDF_VERSION_ABOVE_5_4_0
pwm_config.flags.allow_pd = 0;
Expand All @@ -430,10 +430,10 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
CHECK_ERR(mcpwm_new_timer(&pwm_config, &timers[mcpwm_group][timer_no]), "Could not initialize the timer in group: " + String(mcpwm_group));
// save variables for later
pwm_periods[mcpwm_group][timer_no] = pwm_config.period_ticks / 2;
params->timers[0] = timers[mcpwm_group][timer_no];
params->timers[0] = timers[mcpwm_group][timer_no];
// if the numer of used channels it not pair skip one channel
// the skipped channel cannot be used with the new timer
// TODO avoid loosing channels like this
// TODO avoid loosing channels like this
if(group_pins_used[mcpwm_group] %2) group_pins_used[mcpwm_group]++;
}else{
// we will use an already instantiated timer
Expand All @@ -446,7 +446,7 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
return SIMPLEFOC_DRIVER_INIT_FAILED;
}
CHECK_ERR(mcpwm_timer_start_stop( params->timers[0], MCPWM_TIMER_STOP_EMPTY), "Failed to stop the timer!");

shared_timer = true;
}

Expand All @@ -463,7 +463,7 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
}
CHECK_ERR(mcpwm_new_operator(&operator_config, &params->oper[i]),"Could not create operator "+String(i));
CHECK_ERR(mcpwm_operator_connect_timer(params->oper[i], params->timers[0]),"Could not connect timer to operator: " + String(i));
}
}
// save the last operator in this group
last_operator[mcpwm_group] = params->oper[no_operators - 1];

Expand All @@ -485,7 +485,7 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
int oper_index = shared_timer ? (int)floor((i + 1) / 2) : (int)floor(i / 2);
CHECK_ERR(mcpwm_new_generator(params->oper[oper_index], &generator_config, &params->generator[i]), "Could not create generator " + String(i) +String(" on pin: ")+String(pins[i]));
}


SIMPLEFOC_ESP32_DRV_DEBUG("Configuring center-aligned pwm.");
for (int i = 0; i < no_pins; i++) {
Expand All @@ -507,15 +507,15 @@ void* _configurePinsMCPWM(long pwm_frequency, int mcpwm_group, int timer_no, int
}

// function setting the duty cycle to the MCPWM pin
void _setDutyCycle(mcpwm_cmpr_handle_t cmpr, uint32_t mcpwm_period, float duty_cycle){
void IRAM_ATTR _setDutyCycle(mcpwm_cmpr_handle_t cmpr, uint32_t mcpwm_period, float duty_cycle){
float duty = _constrain(duty_cycle, 0.0, 1.0);
mcpwm_comparator_set_compare_value(cmpr, (uint32_t)(mcpwm_period*duty));
}

// function setting the duty cycle to the MCPWM pin
void _forcePhaseState(mcpwm_gen_handle_t generator_high, mcpwm_gen_handle_t generator_low, PhaseState phase_state){
// phase state is forced in hardware pwm mode
// esp-idf docs: https://docs.espressif.com/projects/esp-idf/en/v5.1.4/esp32/api-reference/peripherals/mcpwm.html#generator-force-actions
// esp-idf docs: https://docs.espressif.com/projects/esp-idf/en/v5.1.4/esp32/api-reference/peripherals/mcpwm.html#generator-force-actions
// github issue: https://github.com/espressif/esp-idf/issues/12237
mcpwm_generator_set_force_level(generator_high, (phase_state == PHASE_ON || phase_state == PHASE_HI) ? -1 : 0, true);
mcpwm_generator_set_force_level(generator_low, (phase_state == PHASE_ON || phase_state == PHASE_LO) ? -1 : 1, true);
Expand Down
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