BLDC Driver

The BldcDriver component wraps around the ESP MCPWM Peripheral to provide full 6 PWM control over a 3 phase brushless dc motor.

API Reference

Header File

Classes

class BldcDriver : public espp::BaseComponent

Interface for controlling the 6 PWMs (high/low sides for phases A,B,C) of a brushless dc motor (BLDC motor). Wraps around the ESP32 https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/mcpwm.html peripheral.

Public Functions

inline explicit BldcDriver(const Config &config)

Initialize the bldc driver.

Note

Enables the driver.

Parameters:

config – Config used to initialize the driver.

inline ~BldcDriver()

Disable the BldcDriver and destroy it.

inline void enable()

Enable the driver, set the enable pin high (if we were provided an enable pin), and remove any force level on the pins if there was a force level.

inline void disable()

Disable the driver, set the enable pin low (if we were provided an enable pin), add a force level to each pin to force the gates all low.

inline bool is_enabled() const

Check if the driver is enabled.

Returns:

True if the driver is enabled, false otherwise.

inline bool is_faulted()

Check if the driver is faulted.

Note

If no fault pin was provided, this will always return false.

Returns:

True if the driver is faulted, false otherwise.

inline void set_phase_state(int state_a, int state_b, int state_c)

This function does nothing, merely exists for later if we choose to implement it as part of the FOC control algorithm.

Note

The integers provided are -1 (low), 0 (high impedance), and 1 (active) for the 3 possible states.

Parameters:

  • state_a – Desired state for phase A.

  • state_b – Desired state for phase B.

  • state_c – Desired state for phase C.

inline void set_voltage(float ua, float ub, float uc)

Set the phase voltages (in volts) to the driver.

Note

Uses the previously configured power supply voltage and limit voltage (if any was provided) to convert to the appropriate pwm.

Parameters:

  • ua – Desired voltage [0.0f, power_supply_voltage] for phase A.

  • ub – Desired voltage [0.0f, power_supply_voltage] for phase B.

  • uc – Desired voltage [0.0f, power_supply_voltage] for phase C.

inline void set_pwm(float duty_a, float duty_b, float duty_c)

Directly set the duty cycle in range [0.0, 1.0] for each phase.

Parameters:

  • duty_a – Duty cycle [0.0, 1.0] for phase A.

  • duty_b – Duty cycle [0.0, 1.0] for phase B.

  • duty_c – Duty cycle [0.0, 1.0] for phase C.

inline void configure_power(float power_supply_voltage, float voltage_limit = -1.0f)

Update the power supply configuration and optional motor voltage limit.

Parameters:

  • power_supply_voltage – New max voltage (volts) from the power supply.

  • voltage_limit – New limit voltage (volts) to allow to the motor.

inline float get_voltage_limit() const

Get the current motor voltage limit (if any).

Returns:

Voltage limit the driver will allow to the motor.

inline float get_power_supply_limit() const

Get the configured power supply voltage.

Returns:

Maximum voltage the driver can supply to the motor.

inline void set_power_supply_voltage(float voltage)

Set the power supply voltage.

Note

Will update the voltage limit to the minimum of the current limit and the new power supply voltage.

Parameters:

voltage – New power supply voltage.

inline void set_voltage_limit(float voltage)

Set the voltage limit.

Note

Will be clamped to the power supply voltage.

Parameters:

voltage – New voltage limit.

inline const std::string &get_name() const

Get the name of the component

Note

This is the tag of the logger

Returns:

A const reference to the name of the component

inline void set_log_tag(const std::string_view &tag)

Set the tag for the logger

Parameters:

tag – The tag to use for the logger

inline espp::Logger::Verbosity get_log_level() const

Get the log level for the logger

See also

Logger::Verbosity

See also

Logger::set_verbosity

Returns:

The verbosity level of the logger

inline void set_log_level(espp::Logger::Verbosity level)

Set the log level for the logger

See also

Logger::Verbosity

See also

Logger::set_verbosity

Parameters:

level – The verbosity level to use for the logger

inline void set_log_verbosity(espp::Logger::Verbosity level)

Set the log verbosity for the logger

See also

set_log_level

See also

Logger::Verbosity

See also

Logger::set_verbosity

Note

This is a convenience method that calls set_log_level

Parameters:

level – The verbosity level to use for the logger

inline espp::Logger::Verbosity get_log_verbosity() const

Get the log verbosity for the logger

See also

get_log_level

See also

Logger::Verbosity

See also

Logger::get_verbosity

Note

This is a convenience method that calls get_log_level

Returns:

The verbosity level of the logger

inline void set_log_rate_limit(std::chrono::duration<float> rate_limit)

Set the rate limit for the logger

See also

Logger::set_rate_limit

Note

Only calls to the logger that have _rate_limit suffix will be rate limited

Parameters:

rate_limit – The rate limit to use for the logger

struct Config

Configure the driver for 6-channel control of a BLDC.

Public Members

int gpio_a_h

Phase A high side gpio.

int gpio_a_l

Phase A low side gpio.

int gpio_b_h

Phase B high side gpio.

int gpio_b_l

Phase B low side gpio.

int gpio_c_h

Phase C high side gpio.

int gpio_c_l

Phase C low side gpio.

int gpio_enable = {-1}

Enable pin for the BLDC driver (if any).

int gpio_fault = {-1}

Fault pin for the BLDC driver (if any).

float power_supply_voltage

Voltage of the power supply.

float limit_voltage = {-1}

What voltage the motor should be limited to. Less than 0 means no limit. Will be clamped to power supply voltage.

uint64_t dead_zone_ns{100}

Dead zone in nanoseconds. Will be applied to both sides of the waveform.

espp::Logger::Verbosity log_level = {espp::Logger::Verbosity::WARN}

Verbosity for the bldc driver.