CAN API Functions

Functions
HAL_CANHandle	HAL_InitializeCAN (HAL_CANManufacturer manufacturer, int32_t deviceId, HAL_CANDeviceType deviceType, int32_t *status)
	Initializes a CAN device. More...
void	HAL_CleanCAN (HAL_CANHandle handle)
	Frees a CAN device. More...
void	HAL_WriteCANPacket (HAL_CANHandle handle, const uint8_t *data, int32_t length, int32_t apiId, int32_t *status)
	Writes a packet to the CAN device with a specific ID. More...
void	HAL_WriteCANPacketRepeating (HAL_CANHandle handle, const uint8_t *data, int32_t length, int32_t apiId, int32_t repeatMs, int32_t *status)
	Writes a repeating packet to the CAN device with a specific ID. More...
void	HAL_WriteCANRTRFrame (HAL_CANHandle handle, int32_t length, int32_t apiId, int32_t *status)
	Writes an RTR frame of the specified length to the CAN device with the specific ID. More...
void	HAL_StopCANPacketRepeating (HAL_CANHandle handle, int32_t apiId, int32_t *status)
	Stops a repeating packet with a specific ID. More...
void	HAL_ReadCANPacketNew (HAL_CANHandle handle, int32_t apiId, uint8_t *data, int32_t *length, uint64_t *receivedTimestamp, int32_t *status)
	Reads a new CAN packet. More...
void	HAL_ReadCANPacketLatest (HAL_CANHandle handle, int32_t apiId, uint8_t *data, int32_t *length, uint64_t *receivedTimestamp, int32_t *status)
	Reads a CAN packet. More...
void	HAL_ReadCANPacketTimeout (HAL_CANHandle handle, int32_t apiId, uint8_t *data, int32_t *length, uint64_t *receivedTimestamp, int32_t timeoutMs, int32_t *status)
	Reads a CAN packet. More...
	HAL_ENUM (HAL_CANDeviceType)
	The CAN device type. More...
	HAL_ENUM (HAL_CANManufacturer)
	The CAN manufacturer ID. More...

Detailed Description

Function Documentation

HAL_CleanCAN()

void HAL_CleanCAN

(

HAL_CANHandle

handle

)

Frees a CAN device.

Parameters

handle

the CAN handle

HAL_ENUM() [1/2]

HAL_ENUM

(

HAL_CANDeviceType

)

The CAN device type.

Teams should use HAL_CAN_Dev_kMiscellaneous

HAL_ENUM() [2/2]

HAL_ENUM

(

HAL_CANManufacturer

)

The CAN manufacturer ID.

Teams should use HAL_CAN_Man_kTeamUse.

HAL_InitializeCAN()

HAL_CANHandle HAL_InitializeCAN	(	HAL_CANManufacturer	manufacturer,
		int32_t	deviceId,
		HAL_CANDeviceType	deviceType,
		int32_t *	status
	)

Initializes a CAN device.

These follow the FIRST standard CAN layout. https://docs.wpilib.org/en/stable/docs/software/can-devices/can-addressing.html

Parameters

[in]	manufacturer	the can manufacturer
[in]	deviceId	the device ID (0-63)
[in]	deviceType	the device type
[out]	status	Error status variable. 0 on success.

Returns

the created CAN handle

HAL_ReadCANPacketLatest()

void HAL_ReadCANPacketLatest	(	HAL_CANHandle	handle,
		int32_t	apiId,
		uint8_t *	data,
		int32_t *	length,
		uint64_t *	receivedTimestamp,
		int32_t *	status
	)

Reads a CAN packet.

The will continuously return the last packet received, without accounting for packet age.

Parameters

[in]	handle	the CAN handle
[in]	apiId	the ID to read (0-1023)
[out]	data	the packet data (8 bytes)
[out]	length	the received length (0-8 bytes)
[out]	receivedTimestamp	the packet received timestamp (based off of CLOCK_MONOTONIC)
[out]	status	Error status variable. 0 on success.

HAL_ReadCANPacketNew()

void HAL_ReadCANPacketNew	(	HAL_CANHandle	handle,
		int32_t	apiId,
		uint8_t *	data,
		int32_t *	length,
		uint64_t *	receivedTimestamp,
		int32_t *	status
	)

Reads a new CAN packet.

This will only return properly once per packet received. Multiple calls without receiving another packet will return an error code.

Parameters

[in]	handle	the CAN handle
[in]	apiId	the ID to read (0-1023)
[out]	data	the packet data (8 bytes)
[out]	length	the received length (0-8 bytes)
[out]	receivedTimestamp	the packet received timestamp (based off of CLOCK_MONOTONIC)
[out]	status	Error status variable. 0 on success.

HAL_ReadCANPacketTimeout()

void HAL_ReadCANPacketTimeout	(	HAL_CANHandle	handle,
		int32_t	apiId,
		uint8_t *	data,
		int32_t *	length,
		uint64_t *	receivedTimestamp,
		int32_t	timeoutMs,
		int32_t *	status
	)

Reads a CAN packet.

The will return the last packet received until the packet is older then the requested timeout. Then it will return an error code.

Parameters

[in]	handle	the CAN handle
[in]	apiId	the ID to read (0-1023)
[out]	data	the packet data (8 bytes)
[out]	length	the received length (0-8 bytes)
[out]	receivedTimestamp	the packet received timestamp (based off of CLOCK_MONOTONIC)
[out]	timeoutMs	the timeout time for the packet
[out]	status	Error status variable. 0 on success.

HAL_StopCANPacketRepeating()

void HAL_StopCANPacketRepeating	(	HAL_CANHandle	handle,
		int32_t	apiId,
		int32_t *	status
	)

Stops a repeating packet with a specific ID.

This ID is 10 bits.

Parameters

[in]	handle	the CAN handle
[in]	apiId	the ID to stop repeating (0-1023)
[out]	status	Error status variable. 0 on success.

HAL_WriteCANPacket()

void HAL_WriteCANPacket	(	HAL_CANHandle	handle,
		const uint8_t *	data,
		int32_t	length,
		int32_t	apiId,
		int32_t *	status
	)

Writes a packet to the CAN device with a specific ID.

This ID is 10 bits.

Parameters

[in]	handle	the CAN handle
[in]	data	the data to write (0-8 bytes)
[in]	length	the length of data (0-8)
[in]	apiId	the ID to write (0-1023 bits)
[out]	status	Error status variable. 0 on success.

HAL_WriteCANPacketRepeating()

void HAL_WriteCANPacketRepeating	(	HAL_CANHandle	handle,
		const uint8_t *	data,
		int32_t	length,
		int32_t	apiId,
		int32_t	repeatMs,
		int32_t *	status
	)

Writes a repeating packet to the CAN device with a specific ID.

This ID is 10 bits.

The RoboRIO will automatically repeat the packet at the specified interval

Parameters

[in]	handle	the CAN handle
[in]	data	the data to write (0-8 bytes)
[in]	length	the length of data (0-8)
[in]	apiId	the ID to write (0-1023)
[in]	repeatMs	the period to repeat in ms
[out]	status	Error status variable. 0 on success.

HAL_WriteCANRTRFrame()

void HAL_WriteCANRTRFrame	(	HAL_CANHandle	handle,
		int32_t	length,
		int32_t	apiId,
		int32_t *	status
	)

Writes an RTR frame of the specified length to the CAN device with the specific ID.

By spec, the length must be equal to the length sent by the other device, otherwise behavior is unspecified.

Parameters

[in]	handle	the CAN handle
[in]	length	the length of data to request (0-8)
[in]	apiId	the ID to write (0-1023)
[out]	status	Error status variable. 0 on success.