esp32_ledc_mcu.cpp

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#include "../../hardware_api.h"
 
#if defined(ESP_H) && defined(ARDUINO_ARCH_ESP32) && ( !defined(SOC_MCPWM_SUPPORTED) || defined(SIMPLEFOC_ESP32_USELEDC) )
 
#pragma message("")
#pragma message("SimpleFOC: compiling for ESP32 LEDC driver")
#pragma message("")
 
#include "driver/ledc.h"
#include "esp_idf_version.h"
 
 
// version check - this ledc driver is specific for ESP-IDF 5.x and arduino-esp32 3.x
#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(5, 0, 0)
#error SimpleFOC: ESP-IDF version 4 or lower detected. Please update to ESP-IDF 5.x and Arduino-esp32 3.0 (or higher)
#endif
 
#define _PWM_FREQUENCY 25000 // 25khz
#define _PWM_FREQUENCY_MAX 38000 // 38khz max to be able to have 10 bit pwm resolution
#define _PWM_RES_BIT 10  // 10 bir resolution
#define _PWM_RES 1023 // 2^10-1 = 1024-1
 
 
// figure out how many ledc channels are available
// esp32   - 2x8=16
// esp32s2 - 8
// esp32c3 - 6
#include "soc/soc_caps.h"
#ifdef SOC_LEDC_SUPPORT_HS_MODE
#define LEDC_CHANNELS           (SOC_LEDC_CHANNEL_NUM<<1)
#else
#define LEDC_CHANNELS           (SOC_LEDC_CHANNEL_NUM)
#endif
 
#define LEDC_CHANNELS_GROUP0   (LEDC_CHANNELS < 8 ? LEDC_CHANNELS : 8)
#define LEDC_CHANNELS_GROUP1   (LEDC_CHANNELS < 8 ? 0 : LEDC_CHANNELS - 8)
 
 
// currently used ledc channels
// support for multiple motors
// esp32 has 16 channels
// esp32s2 has 8 channels
// esp32c3 has 6 channels
// channels from 0-7 are in group 0 and 8-15 in group 1
// - only esp32 as of mid 2024 has the second group, all the s versions don't
int group_channels_used[2] = {0};
 
 
typedef struct ESP32LEDCDriverParams {
  ledc_channel_t channels[6];
  ledc_mode_t groups[6];
  long pwm_frequency;
  float dead_zone;
} ESP32LEDCDriverParams;
 
 
 
int esp32_gpio_nr(int pin) {
  #if defined(BOARD_HAS_PIN_REMAP) && !defined(BOARD_USES_HW_GPIO_NUMBERS)
    return digitalPinToGPIONumber(pin);
  #else
    return pin;
  #endif
}
 
 
/*
  Function to attach a channel to a pin with advanced settings
  - freq - pwm frequency
  - resolution - pwm resolution
  - channel - ledc channel
  - inverted - output inverted
  - group - ledc group
 
  This function is a workaround for the ledcAttachPin function that is not available in the ESP32 Arduino core, in which the
  PWM signals are synchronized in pairs, while the simplefoc requires a bit more flexible configuration.
  This function sets also allows configuring a channel as inverted, which is not possible with the ledcAttachPin function.
 
  Function returns true if the channel was successfully attached, false otherwise.
*/
bool _ledcAttachChannelAdvanced(uint8_t pin, int _channel, int _group, uint32_t freq, uint8_t resolution,  bool inverted) {
 
 
  ledc_channel_t channel = static_cast<ledc_channel_t>(_channel);
  ledc_mode_t group = static_cast<ledc_mode_t>(_group);
 
  ledc_timer_bit_t res = static_cast<ledc_timer_bit_t>(resolution);
  ledc_timer_config_t ledc_timer;
  memset(&ledc_timer, 0, sizeof(ledc_timer));
  ledc_timer.speed_mode = group;
  ledc_timer.timer_num = LEDC_TIMER_0;
  ledc_timer.duty_resolution = res;
  ledc_timer.freq_hz = freq;
  ledc_timer.clk_cfg = LEDC_AUTO_CLK;
  if (ledc_timer_config(&ledc_timer) != ESP_OK) {
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure the timer:", LEDC_TIMER_0);
    return false;
  }
 
  // if active high is false invert
  int pin_high_level = SIMPLEFOC_PWM_ACTIVE_HIGH ? 0 : 1;
  if (inverted) pin_high_level = !pin_high_level;
 
  uint32_t duty = ledc_get_duty(group, channel);
  ledc_channel_config_t ledc_channel;
  ledc_channel.speed_mode = group;
  ledc_channel.sleep_mode = LEDC_SLEEP_MODE_KEEP_ALIVE;
  ledc_channel.channel =  channel;
  ledc_channel.timer_sel = LEDC_TIMER_0;
  ledc_channel.intr_type = LEDC_INTR_DISABLE;
  ledc_channel.gpio_num = esp32_gpio_nr(pin);
  ledc_channel.duty = duty;
  ledc_channel.hpoint = 0;
  ledc_channel.flags.output_invert = pin_high_level; // 0 is active high, 1 is active low
  if (ledc_channel_config(&ledc_channel)!= ESP_OK) {
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to attach channel:", _channel);
    return false;
  }
 
  return true;
}
 
 
// returns the number of available channels in the group
int _availableGroupChannels(int group){
  if(group == 0) return LEDC_CHANNELS_GROUP0 - group_channels_used[0];
  else if(group == 1) return LEDC_CHANNELS_GROUP1 - group_channels_used[1];
  return 0;
}
 
// returns the number of the group that has enough channels available
// returns -1 if no group has enough channels
//
// NOT IMPLEMENTED BUT COULD BE USEFUL
// returns 2 if no group has enough channels but combined they do
int _findGroupWithChannelsAvailable(int no_channels){
  if(no_channels <= _availableGroupChannels(0)) return 0;
  if(no_channels <= _availableGroupChannels(1)) return 1;
  return -1;
}
 
 
void* _configure1PWM(long pwm_frequency, const int pinA) {
  if(!pwm_frequency || !_isset(pwm_frequency) ) pwm_frequency = _PWM_FREQUENCY; // default frequency 25khz
  else pwm_frequency = _constrain(pwm_frequency, 0, _PWM_FREQUENCY_MAX); // constrain to 50kHz max
 
  SIMPLEFOC_DEBUG("EP32-DRV: Configuring 1PWM");
  // check if enough channels available
  int group = _findGroupWithChannelsAvailable(1);
  if (group < 0){
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Not enough channels available!");
    return SIMPLEFOC_DRIVER_INIT_FAILED;
  }
 SIMPLEFOC_DEBUG("EP32-DRV: 1PWM setup in group: ", (group));
 
  // configure the channel
  group_channels_used[group] += 1;
  if(!_ledcAttachChannelAdvanced(pinA, group_channels_used[group], group, pwm_frequency, _PWM_RES_BIT, false)){
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pinA);
    return SIMPLEFOC_DRIVER_INIT_FAILED;
  }
 
 
  ESP32LEDCDriverParams* params = new ESP32LEDCDriverParams {
    .channels = {  static_cast<ledc_channel_t>(group_channels_used[group]) },
    .groups = { (ledc_mode_t)group },
    .pwm_frequency = pwm_frequency
  };
  SIMPLEFOC_DEBUG("EP32-DRV: 1PWM setup successful in group: ", (group));
  return params;
}
 
 
 
 
 
 
 
 
void* _configure2PWM(long pwm_frequency, const int pinA, const int pinB) {
  if(!pwm_frequency || !_isset(pwm_frequency) ) pwm_frequency = _PWM_FREQUENCY; // default frequency 25khz
  else pwm_frequency = _constrain(pwm_frequency, 0, _PWM_FREQUENCY_MAX); // constrain to 50kHz max
 
  SIMPLEFOC_DEBUG("EP32-DRV: Configuring 2PWM");
 
  // check if enough channels available
  int group = _findGroupWithChannelsAvailable(2);
  if (group < 0) {
   SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Not enough channels available!");
    return SIMPLEFOC_DRIVER_INIT_FAILED;
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 2PWM setup in group: ", (group));
 
  ESP32LEDCDriverParams* params = new ESP32LEDCDriverParams {
    .channels = {  static_cast<ledc_channel_t>(0)},
    .groups = { (ledc_mode_t)0 },
    .pwm_frequency = pwm_frequency
  };
 
  int pins[2] = {pinA, pinB};
  for(int i = 0; i < 2; i++){
    group_channels_used[group]++;
    if(!_ledcAttachChannelAdvanced(pins[i], group_channels_used[group], group, pwm_frequency, _PWM_RES_BIT, false)){
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pins[i]);
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
 
    params->channels[i] = static_cast<ledc_channel_t>(group_channels_used[group]);
    params->groups[i] = (ledc_mode_t)group;
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 2PWM setup successful in group: ", (group));
  return params;
}
 
 
 
void* _configure3PWM(long pwm_frequency,const int pinA, const int pinB, const int pinC) {
  if(!pwm_frequency || !_isset(pwm_frequency) ) pwm_frequency = _PWM_FREQUENCY; // default frequency 25khz
  else pwm_frequency = _constrain(pwm_frequency, 0, _PWM_FREQUENCY_MAX); // constrain to 50kHz max
 
  SIMPLEFOC_DEBUG("EP32-DRV: Configuring 3PWM");
 
  // check if enough channels available
  int group = _findGroupWithChannelsAvailable(3);
  if (group < 0) {
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Not enough channels available!");
    return SIMPLEFOC_DRIVER_INIT_FAILED;
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 3PWM setup in group: ", (group));
 
  ESP32LEDCDriverParams* params = new ESP32LEDCDriverParams {
    .channels = {  static_cast<ledc_channel_t>(0)},
    .groups = { (ledc_mode_t)0 },
    .pwm_frequency = pwm_frequency
  };
 
  int pins[3] = {pinA, pinB, pinC};
  for(int i = 0; i < 3; i++){
    if(!_ledcAttachChannelAdvanced(pins[i], group_channels_used[group], group, pwm_frequency, _PWM_RES_BIT, false)){
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pins[i]);
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
 
    params->channels[i] = static_cast<ledc_channel_t>(group_channels_used[group]);
    params->groups[i] = (ledc_mode_t)group;
    group_channels_used[group]++;
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 3PWM setup successful in group: ", (group));
  return params;
}
 
 
 
void* _configure4PWM(long pwm_frequency,const int pinA, const int pinB, const int pinC, const int pinD) {
  if(!pwm_frequency || !_isset(pwm_frequency) ) pwm_frequency = _PWM_FREQUENCY; // default frequency 25khz
  else pwm_frequency = _constrain(pwm_frequency, 0, _PWM_FREQUENCY_MAX); // constrain to 50kHz max
 
 
  ESP32LEDCDriverParams* params = new ESP32LEDCDriverParams {
    .channels = {  static_cast<ledc_channel_t>(0)},
    .groups = { (ledc_mode_t)0 },
    .pwm_frequency = pwm_frequency
  };
 
  SIMPLEFOC_DEBUG("EP32-DRV: Configuring 4PWM");
  // check if enough channels available
  int group = _findGroupWithChannelsAvailable(4);
  if (group < 0){
    // not enough channels available on any individual group
    // check if their combined number is enough (two channels per group)
    if(_availableGroupChannels(0) >=2 && _availableGroupChannels(1) >=2){
      group = 2;
      SIMPLEFOC_DEBUG("EP32-DRV: WARNING: Not enough available ledc channels for 4pwm in a single group! Using two groups!");
      SIMPLEFOC_DEBUG("EP32-DRV: 4PWM setup in groups: 0 and 1!");
      params->groups[2] = (ledc_mode_t)1;
      params->groups[3] = (ledc_mode_t)1;
    }else{
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Not enough available ledc channels for 4pwm!");
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
  }else{
    SIMPLEFOC_DEBUG("EP32-DRV: 4PWM setup in group: ", (group));
    params->groups[0] = (ledc_mode_t)group;
    params->groups[1] = (ledc_mode_t)group;
    params->groups[2] = (ledc_mode_t)group;
    params->groups[3] = (ledc_mode_t)group;
  }
 
 
 
  int pins[4] = {pinA, pinB, pinC, pinD};
  for(int i = 0; i < 4; i++){
    group_channels_used[params->groups[i]]++;
    if(!_ledcAttachChannelAdvanced(pins[i], group_channels_used[params->groups[i]], params->groups[i], pwm_frequency, _PWM_RES_BIT, false)){
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pins[i]);
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
    params->channels[i] = static_cast<ledc_channel_t>(group_channels_used[params->groups[i]]);
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 4PWM setup successful!");
  return params;
}
 
 
void IRAM_ATTR _writeDutyCycle(float dc, void* params, int index){
  ledc_set_duty_with_hpoint(((ESP32LEDCDriverParams*)params)->groups[index],((ESP32LEDCDriverParams*)params)->channels[index], _PWM_RES*dc, _PWM_RES/2.0*(1.0-dc));
  ledc_update_duty(((ESP32LEDCDriverParams*)params)->groups[index],((ESP32LEDCDriverParams*)params)->channels[index]);
}
 
void IRAM_ATTR _writeDutyCycle1PWM(float dc_a, void* params){
  _writeDutyCycle(dc_a, params, 0);
}
 
 
 
void IRAM_ATTR _writeDutyCycle2PWM(float dc_a,  float dc_b, void* params){
  _writeDutyCycle(dc_a, params, 0);
  _writeDutyCycle(dc_b, params, 1);
}
 
 
 
void IRAM_ATTR _writeDutyCycle3PWM(float dc_a,  float dc_b, float dc_c, void* params){
  _writeDutyCycle(dc_a, params, 0);
  _writeDutyCycle(dc_b, params, 1);
  _writeDutyCycle(dc_c, params, 2);
}
 
 
 
void IRAM_ATTR _writeDutyCycle4PWM(float dc_1a,  float dc_1b, float dc_2a, float dc_2b, void* params){
  _writeDutyCycle(dc_1a, params, 0);
  _writeDutyCycle(dc_1b, params, 1);
  _writeDutyCycle(dc_2a, params, 2);
  _writeDutyCycle(dc_2b, params, 3);
}
 
 
void* _configure6PWM(long pwm_frequency, float dead_zone, const int pinA_h, const int pinA_l,  const int pinB_h, const int pinB_l, const int pinC_h, const int pinC_l){
  if(!pwm_frequency || !_isset(pwm_frequency) ) pwm_frequency = _PWM_FREQUENCY; // default frequency 25khz
  else pwm_frequency = _constrain(pwm_frequency, 0, _PWM_FREQUENCY_MAX); // constrain to 50kHz max
 
  SIMPLEFOC_DEBUG("EP32-DRV: Configuring 6PWM");
  SIMPLEFOC_DEBUG("EP32-DRV: WARNING - 6PWM on LEDC is poorly supported and not tested, consider using MCPWM driver instead!");
  // check if enough channels available
  int group = _findGroupWithChannelsAvailable(6);
  if (group < 0){
    SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Not enough channels available!");
    return SIMPLEFOC_DRIVER_INIT_FAILED;
  }
  SIMPLEFOC_DEBUG("EP32-DRV: 6PWM setup in group: ", (group));
  ESP32LEDCDriverParams* params = new ESP32LEDCDriverParams {
    .channels = {  static_cast<ledc_channel_t>(0)},
    .groups = { (ledc_mode_t)group },
    .pwm_frequency = pwm_frequency,
    .dead_zone = dead_zone
  };
 
  int high_side_invert = SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH ? false : true;
  int low_side_invert = SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH ? true : false;
 
  int pin_pairs[6][2] = {
    {pinA_h, pinA_l},
    {pinB_h, pinB_l},
    {pinC_h, pinC_l}
  };
 
  for(int i = 0; i < 3; i++){
    group_channels_used[group]++;
    if(!_ledcAttachChannelAdvanced(pin_pairs[i][0], group_channels_used[group], group, pwm_frequency, _PWM_RES_BIT, high_side_invert)){
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pin_pairs[i][0]);
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
 
    params->channels[2*i] = static_cast<ledc_channel_t>(group_channels_used[group]);
    params->groups[2*i] = (ledc_mode_t)group;
 
    group_channels_used[group]++;
    if(!_ledcAttachChannelAdvanced(pin_pairs[i][1], group_channels_used[group], group, pwm_frequency, _PWM_RES_BIT, low_side_invert)){
      SIMPLEFOC_DEBUG("EP32-DRV: ERROR - Failed to configure pin:",  pin_pairs[i][0]);
      return SIMPLEFOC_DRIVER_INIT_FAILED;
    }
 
    params->channels[2*i+1] = static_cast<ledc_channel_t>(group_channels_used[group]);
    params->groups[2*i+1] = (ledc_mode_t)group;
  }
 
  SIMPLEFOC_DEBUG("EP32-DRV: 6PWM setup successful in group: ", (group));
  return params;
}
 
void IRAM_ATTR _setPwmPairDutyCycle( void* params, int ind_h, int ind_l, float val, float dead_time, PhaseState ps){
  float pwm_h = _constrain(val - (dead_time * 0.5), 0, 1.0);
  float pwm_l = _constrain(val + (dead_time * 0.5), 0, 1.0);
 
  // determine the phase state and set the pwm accordingly
  // deactivate phases if needed
  if((ps == PhaseState::PHASE_OFF) || (ps == PhaseState::PHASE_LO)){
    _writeDutyCycle(0, params, ind_h);
  }else{
    _writeDutyCycle(pwm_h, params, ind_h);
  }
  if((ps == PhaseState::PHASE_OFF) || (ps == PhaseState::PHASE_HI)){
    _writeDutyCycle(0, params, ind_l);
  }else{
    _writeDutyCycle(pwm_l, params, ind_l);
  }
}
 
void IRAM_ATTR _writeDutyCycle6PWM(float dc_a,  float dc_b, float dc_c,  PhaseState *phase_state, void* params){
  _setPwmPairDutyCycle(params, 0, 1, dc_a, ((ESP32LEDCDriverParams*)params)->dead_zone, phase_state[0]);
  _setPwmPairDutyCycle(params, 2, 3, dc_b, ((ESP32LEDCDriverParams*)params)->dead_zone, phase_state[1]);
  _setPwmPairDutyCycle(params, 4, 5, dc_c, ((ESP32LEDCDriverParams*)params)->dead_zone, phase_state[2]);
}
 
#endif