CAN Driver API Reference. More...

Functions list
void	can_configure_default (can_config_t *config)
	Configure CAN Driver configuration structure. More...

void	can_filter_configure_default (can_filter_config_t *filter_config)
	Configure CAN Driver filter configuration structure. More...

err_t	can_open (can_t obj, can_config_t config)
	Open the CAN driver object. More...

err_t	can_init (can_t *obj)
	Initialize CAN module. More...

err_t	can_set_filter (can_t obj, can_filter_config_t filter_config)
	Initialize CAN module filter. More...

err_t	can_set_frequency (can_t *obj, uint32_t frequency)
	Set CAN module frequency. More...

err_t	can_get_frequency (can_t *obj)
	Get CAN module frequency. More...

err_t	can_set_mode (can_t *obj, can_mode_t mode)
	Set CAN module mode. More...

err_t	can_get_mode (can_t *obj)
	Get CAN module mode. More...

err_t	can_transmit (can_t obj, can_transmit_message_struct transmit_message)
	Transmit data to the first free TX mailbox. More...

void	can_transmission_stop (can_t *obj)
	Stop transmit operation. More...

err_t	can_receive (can_t obj, can_receive_message_struct receive_message)
	Get data from the RX FIFO. More...

err_t	can_close (can_t *obj)
	Close CAN driver object. More...

Detailed Description

The CAN driver provides standard CAN functionality.

Function Documentation

◆ can_configure_default()

void can_configure_default ( can_config_t * config )

Configures can_config_t structure to default initialization values. Take into consideration that this is just structure variable initial values setting. Values need to be redefined by user.

Parameters

[in,out] config configure CAN driver configuration structure. See can_config_t structure definition for detailed explanation.

Default values:

Function	Default value
Tx pin	0xFFFFFFFF (invalid pin)
Rx pin	0xFFFFFFFF (invalid pin)
Mode	CAN_MODE_NORMAL
Frequency	500000

Returns: Nothing.

Example

// CAN driver configuration structure.
static can_config_t can_cfg;
 
// Fill structure with default values.
can_configure_default( &can_cfg );

◆ can_filter_configure_default()

void can_filter_configure_default ( can_filter_config_t * filter_config )

Configures can_filter_config_t structure to default initialization values. Take into consideration that this is just structure variable initial values setting. Values need to be redefined by user.

Parameters

[in,out] filter_config configure CAN driver filter configuration structure. See can_filter_config_t structure definition for detailed explanation.

Default values:

Function	Default value
ID high	0x0000
ID low	0x0000
ID mask high	0x0000
ID mask low	0x0000
Filter mode	CAN_FILTER_MODE_IDMASK
Filter scale	CAN_FILTER_SCALE_16BIT
Filter enable	CAN_FILTER_DISABLE
Filter FIFO	CAN_FILTER_FIFO0
Filter bank	0

Returns: Nothing.

Example

// CAN driver configuration structure.
static can_filter_config_t can_filter_cfg;
 
// Fill structure with default values.
can_filter_configure_default( &can_filter_cfg );

◆ can_open()

err_t can_open	(	can_t *	obj,
		can_config_t *	config
	)

Opens the CAN driver object on selected pins. Allocates memory and pins for specified object.

Parameters

[in,out]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	config	CAN driver configuration settings. See can_config_t structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that config structure has been adequately populated beforehand. See can_configure_default definition for detailed explanation.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
// CAN driver configuration structure.
static can_config_t can_cfg;
 
// Specify desired TX pin.
can_cfg.tx_pin = CAN_TX;
 
// Specify desired RX pin.
can_cfg.rx_pin = CAN_RX;
 
// Allocate resources for CAN module.
if ( can_open( &can, &can_cfg ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_init()

err_t can_init ( can_t * obj )

Sets CAN module parameters.

Parameters

[in] obj CAN driver object. See can_t structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Before calling this function, the user is expected to call can_open function.

Postcondition: This function initializes CAN module and sets adequate parameters.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// Call the function.
if ( can_init( &can ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_set_filter()

err_t can_set_filter	(	can_t *	obj,
		can_filter_config_t *	filter_config
	)

Sets CAN module filter parameters.

Parameters

[in]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	filter_config	CAN filter config structure. See can_filter_config_t structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that can_filter_config_t structure has been adequately filled out.

Postcondition: This function initializes CAN filter and sets adequate parameters.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// CAN driver filter config structure.
static can_filter_config_t can_filter_cfg;
 
// Configure CAN filter.
if ( can_set_filter( &can, &can_filter_cfg ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_set_frequency()

err_t can_set_frequency	(	can_t *	obj,
		uint32_t	frequency
	)

Sets CAN module frequency to frequency value if possible. Frequency must be set to exact amount as requested, otherwise error is returned.

Parameters

[in]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	frequency	Specified CAN transmission rate.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that adequate memory has been allocated beforehand. See can_open definition for detailed explanation.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// Set transmission rate.
if ( can_set_frequency( &can, 500000 ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_get_frequency()

err_t can_get_frequency ( can_t * obj )

Gets the currently configured CAN frequency.

Parameters

[in] obj CAN driver object. See can_t structure definition for detailed explanation.

Returns: The function can return the CAN_ERROR value defined by can_err_t, which is size dependant on the architecture, or the actual frequency.

Precondition: Make sure that adequate memory has been allocated beforehand. See can_open definition for detailed explanation.

Example

// CAN driver context structure.
static can_t can;
 
// Get transmission rate.
int32_t frequency = can_get_frequency( &can );

◆ can_set_mode()

err_t can_set_mode	(	can_t *	obj,
		can_mode_t	mode
	)

Sets CAN module mode to mode if possible.

Parameters

[in]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	mode	Specified CAN mode. See can_mode_t definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that adequate memory has been allocated beforehand. See can_open definition for detailed explanation.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// Set mode.
if ( can_set_mode( &can, CAN_MODE_NORMAL ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_get_mode()

err_t can_get_mode ( can_t * obj )

Gets the currently configured CAN mode.

Parameters

[in] obj CAN driver object. See can_t structure definition for detailed explanation.

Returns: The function can return the CAN_ERROR value defined by can_err_t, which is size dependant on the architecture, or the actual mode.

Precondition: Make sure that adequate memory has been allocated beforehand. See can_open definition for detailed explanation.

Example

// CAN driver context structure.
static can_t can;
 
// Get mode.
can_mode_t mode = can_get_mode( &can );

◆ can_transmit()

err_t can_transmit	(	can_t *	obj,
		can_transmit_message_struct *	transmit_message
	)

Function sets parameters from the transmit message structure in the appropriate registers and then sends out the data.

Parameters

[in]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	transmit_message	Structure containing necessary information about the message being transmitted. See #can_message_struct structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that adequate memory has been allocated beforehand, and the module has been initialized to adequate CAN frequency. See can_open definition and can_set_frequency for detailed explanation.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// CAN transmit structure.
can_transmit_message_struct *tx_message;
 
// Set the ID type.
tx_message.tx_id_type = CAN_FRAME_FORMAT_STANDARD_11BITS;
 
// Set a unique standard ID.
tx_message.tx_std_id = 0x321;
 
// Set the length of the message in bytes.
tx_message.tx_data_len = 3;
 
// Set the data.
tx_message.tx_data[0] = 0xAA;
tx_message.tx_data[1] = 0xBB;
tx_message.tx_data[2] = 0xCC;
 
if ( can_transmit( &can, &tx_message ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_transmission_stop()

void can_transmission_stop ( can_t * obj )

Function accesses hardware transmit registers, finds the transmit mailbox that has message transmission request in progress and stops data transmission.

Parameters

[in] obj CAN driver object.

Returns: void None.

Precondition: Make sure that there is transmission in progress. See can_transmit definition for detailed explanation.

Example

// CAN HAL context structure.
static hal_can_t hal_can;
 
// Stop transmission.
hal_can_transmission_stop( &hal_can );

◆ can_receive()

err_t can_receive	(	can_t *	obj,
		can_receive_message_struct *	receive_message
	)

Function stores previously transmitted data into the rx_data in receive_message structure.

Parameters

[in]	obj	CAN driver object. See can_t structure definition for detailed explanation.
[in]	receive_message	Structure designed to store received information and data retrieved from the CAN registers. See #can_message_struct structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Precondition: Make sure that adequate memory has been allocated beforehand, and the module has been initialized to adequate CAN frequency. See can_open definition and can_set_frequency for detailed explanation.

Note: It is recommended to check return value for error.

Example

// CAN driver context structure.
static can_t can;
 
// CAN receive structure.
can_receive_message_struct *rx_message;
 
if ( can_receive( &can, &rx_message ) == CAN_ERROR )
{
 // Error handling strategy.
}

◆ can_close()

err_t can_close ( can_t * obj )

De-allocates hardware resources for specific driver object and de-initializes the module on a hardware level, resets pin AF to default values, clears all buffers used by object and disables module clock for lower power consumption.

Parameters

[in,out] obj CAN driver object. See can_t structure definition for detailed explanation.

Returns: The function can return one of the values defined by can_err_t, which is size dependant on the architecture.

Example

// CAN driver context structure.
static can_t can;
 
// Close the CAN module object handler.
if ( CAN_SUCCESS == can_close( &can ) ) {
 // No error
} else {
 // Handle the error.
}

Functions list

Detailed Description

Function Documentation

◆ can_configure_default()

◆ can_filter_configure_default()

◆ can_open()

◆ can_init()

◆ can_set_filter()

◆ can_set_frequency()

◆ can_get_frequency()

◆ can_set_mode()

◆ can_get_mode()

◆ can_transmit()

◆ can_transmission_stop()

◆ can_receive()

◆ can_close()