High-level driver for DC motors. More...

Detailed Description

High-level driver for DC motors.

This API aims to handle DC motor analogic driver. Driver boards using serial communication protocols (I2C, UART, etc...) are not in the scope of this driver. Mainly designed for H-bridge, it could also drive some brushless drivers.

Some H-bridge driver circuits handle several motors. Maximum motor number by H-bridge is set to 2 with CONFIG_MOTOR_DRIVER_MAX macro. This macro can be overridden to support H-bridge drivers with more outputs. However, CONFIG_MOTOR_DRIVER_MAX should not exceed PWM channels number.

motor_driver_t structure represents an H-bridge. As several H-bridge can share a same PWM device, motor_driver_t can represent a group of H-bridge.

Most of H-bridge boards uses the following I/Os for each motor :

Enable/disable GPIO
One or two direction GPIOs
A PWM signal

*
* Each motor direction is controlled (assuming it is enabled) according to
* the following truth table :
*  __________________________
* | DIR0 | DIR1 |  BEHAVIOR  |
* |--------------------------|
* |  0   |  0   | BRAKE LOW  |
* |  0   |  1   |     CW     |
* |  1   |  0   |     CCW    |
* |  1   |  1   | BRAKE HIGH |
* |______|______|____________|
*
* In case of single GPIO for direction, only DIR0 is used without brake
* capability :
*  ___________________
* | DIR0 |  BEHAVIOR  |
* |-------------------|
* |   0  |     CW     |
* |   1  |     CCW    |
* |______|____________|
*
* Some boards add a brake pin with single direction GPIO :
*  ________________________
* | DIR | BRAKE | BEHAVIOR |
* |------------------------|
* |  0  |   0   |    CW    |
* |  0  |   1   |   BRAKE  |
* |  1  |   0   |    CCW   |
* |  1  |   1   |   BRAKE  |
* |_____|_______|__________|
*
*

From this truth tables we can extract two direction states :

CW (ClockWise)
CCW (Counter ClockWise) and a brake capability

BRAKE LOW is functionally the same than BRAKE HIGH but some H-bridge only brake on BRAKE HIGH due to hardware. In case of single direction GPIO, there is no BRAKE, PWM duty cycle is set to 0.

Modules
	Motor_Driver driver compile configuration

Files
file	motor_driver.h
	High-level driver for DC motors.

Data Structures
struct	motor_t
	Describe DC motor with PWM channel and GPIOs. More...

struct	motor_driver_config_t
	Describe DC motor driver with PWM device and motors array. More...

Macros
#define	MOTOR_DRIVER_DEV(x) (x)
	Macro to return motor driver id.

Typedefs
typedef unsigned int	motor_driver_t
	Default motor driver type definition.

typedef void(*	motor_driver_cb_t) (const motor_driver_t motor_driver, uint8_t motor_id, int32_t pwm_duty_cycle)
	Motor callback. More...

Enumerations
enum	motor_driver_mode_t { MOTOR_DRIVER_2_DIRS = 0, MOTOR_DRIVER_1_DIR = 1, MOTOR_DRIVER_1_DIR_BRAKE = 2 }
	Describe DC motor driver modes. More...

enum	motor_driver_mode_brake_t { MOTOR_BRAKE_LOW = 0, MOTOR_BRAKE_HIGH = 1 }
	Describe DC motor driver brake modes. More...

enum	motor_direction_t { MOTOR_CW = 0, MOTOR_CCW = 1 }
	Describe DC motor direction states. More...

Functions
int	motor_driver_init (const motor_driver_t motor_driver)
	Initialize DC motor driver board. More...

int	motor_set (const motor_driver_t motor_driver, uint8_t motor_id, int32_t pwm_duty_cycle)
	Set motor speed and direction. More...

int	motor_brake (const motor_driver_t motor_driver, uint8_t motor_id)
	Brake the motor of a given motor driver. More...

void	motor_enable (const motor_driver_t motor_driver, uint8_t motor_id)
	Enable a motor of a given motor driver. More...

void	motor_disable (const motor_driver_t motor_driver, uint8_t motor_id)
	Disable a motor of a given motor driver. More...

Typedef Documentation

◆ motor_driver_cb_t

typedef void(* motor_driver_cb_t) (const motor_driver_t motor_driver, uint8_t motor_id, int32_t pwm_duty_cycle)

Motor callback.

It is called at end of motor_set()

Definition at line 161 of file motor_driver.h.

Enumeration Type Documentation

◆ motor_direction_t

enum motor_direction_t

Describe DC motor direction states.

Enumerator
MOTOR_CW	clockwise
MOTOR_CCW	counter clockwise

Definition at line 135 of file motor_driver.h.

◆ motor_driver_mode_brake_t

enum motor_driver_mode_brake_t

Describe DC motor driver brake modes.

Enumerator
MOTOR_BRAKE_LOW	Low stage brake.
MOTOR_BRAKE_HIGH	High stage brake.

Definition at line 127 of file motor_driver.h.

◆ motor_driver_mode_t

enum motor_driver_mode_t

Describe DC motor driver modes.

Enumerator
MOTOR_DRIVER_2_DIRS	2 GPIOS for direction, \ handling BRAKE
MOTOR_DRIVER_1_DIR	Single GPIO for direction, \ no BRAKE.
MOTOR_DRIVER_1_DIR_BRAKE	Single GPIO for direction, \ Single GPIO for BRAKE.

Definition at line 115 of file motor_driver.h.

Function Documentation

◆ motor_brake()

int motor_brake	(	const motor_driver_t	motor_driver,
		uint8_t	motor_id
	)

Brake the motor of a given motor driver.

Parameters

[in]	motor_driver	motor driver to which motor is attached
[in]	motor_id	motor ID on driver

Returns: 0 on success; -1 on error with errno set

◆ motor_disable()

void motor_disable	(	const motor_driver_t	motor_driver,
		uint8_t	motor_id
	)

Disable a motor of a given motor driver.

Parameters

[in]	motor_driver	motor driver to which motor is attached
[in]	motor_id	motor ID on driver

Returns

◆ motor_driver_init()

int motor_driver_init ( const motor_driver_t motor_driver )

Initialize DC motor driver board.

Parameters

[out] motor_driver motor driver to initialize

Returns: 0 on success; -1 on error with errno set

◆ motor_enable()

void motor_enable	(	const motor_driver_t	motor_driver,
		uint8_t	motor_id
	)

Enable a motor of a given motor driver.

Parameters

[in]	motor_driver	motor driver to which motor is attached
[in]	motor_id	motor ID on driver

Returns

◆ motor_set()

int motor_set	(	const motor_driver_t	motor_driver,
		uint8_t	motor_id,
		int32_t	pwm_duty_cycle
	)

Set motor speed and direction.

Parameters

[in]	motor_driver	motor driver to which motor is attached
[in]	motor_id	motor ID on driver
[in]	pwm_duty_cycle	Signed PWM duty_cycle to set motor speed and direction

Returns: 0 on success; -1 on error with errno set

Detailed Description

Modules

Files

Data Structures

Macros

Typedefs

Enumerations

Functions

Typedef Documentation

◆ motor_driver_cb_t

Enumeration Type Documentation

◆ motor_direction_t

◆ motor_driver_mode_brake_t

◆ motor_driver_mode_t

Function Documentation

◆ motor_brake()

◆ motor_disable()

◆ motor_driver_init()

◆ motor_enable()

◆ motor_set()