WPILibC++ 2023.4.3-108-ge5452e3
frc::CAN Class Reference

High level class for interfacing with CAN devices conforming to the standard CAN spec. More...

#include <frc/CAN.h>

Public Member Functions

 CAN (int deviceId)
 Create a new CAN communication interface with the specific device ID. More...
 
 CAN (int deviceId, int deviceManufacturer, int deviceType)
 Create a new CAN communication interface with a specific device ID, manufacturer and device type. More...
 
 ~CAN ()
 Closes the CAN communication. More...
 
 CAN (CAN &&)=default
 
CANoperator= (CAN &&)=default
 
void WritePacket (const uint8_t *data, int length, int apiId)
 Write a packet to the CAN device with a specific ID. More...
 
void WritePacketRepeating (const uint8_t *data, int length, int apiId, int repeatMs)
 Write a repeating packet to the CAN device with a specific ID. More...
 
void WriteRTRFrame (int length, int apiId)
 Write an RTR frame to the CAN device with a specific ID. More...
 
int WritePacketNoError (const uint8_t *data, int length, int apiId)
 Write a packet to the CAN device with a specific ID. More...
 
int WritePacketRepeatingNoError (const uint8_t *data, int length, int apiId, int repeatMs)
 Write a repeating packet to the CAN device with a specific ID. More...
 
int WriteRTRFrameNoError (int length, int apiId)
 Write an RTR frame to the CAN device with a specific ID. More...
 
void StopPacketRepeating (int apiId)
 Stop a repeating packet with a specific ID. More...
 
bool ReadPacketNew (int apiId, CANData *data)
 Read a new CAN packet. More...
 
bool ReadPacketLatest (int apiId, CANData *data)
 Read a CAN packet. More...
 
bool ReadPacketTimeout (int apiId, int timeoutMs, CANData *data)
 Read a CAN packet. More...
 

Static Public Member Functions

static uint64_t GetTimestampBaseTime ()
 Reads the current value of the millisecond-resolution timer that CANData timestamps are based on. More...
 

Static Public Attributes

static constexpr HAL_CANManufacturer kTeamManufacturer = HAL_CAN_Man_kTeamUse
 
static constexpr HAL_CANDeviceType kTeamDeviceType
 

Detailed Description

High level class for interfacing with CAN devices conforming to the standard CAN spec.

No packets that can be sent gets blocked by the RoboRIO, so all methods work identically in all robot modes.

All methods are thread save, however the buffer objects passed in by the user need to not be modified for the duration of their calls.

Constructor & Destructor Documentation

◆ CAN() [1/3]

frc::CAN::CAN ( int  deviceId)
explicit

Create a new CAN communication interface with the specific device ID.

This uses the team manufacturer and device types. The device ID is 6 bits (0-63)

Parameters
deviceIdThe device id

◆ CAN() [2/3]

frc::CAN::CAN ( int  deviceId,
int  deviceManufacturer,
int  deviceType 
)

Create a new CAN communication interface with a specific device ID, manufacturer and device type.

The device ID is 6 bits, the manufacturer is 8 bits, and the device type is 5 bits.

Parameters
deviceIdThe device ID
deviceManufacturerThe device manufacturer
deviceTypeThe device type

◆ ~CAN()

frc::CAN::~CAN ( )

Closes the CAN communication.

◆ CAN() [3/3]

frc::CAN::CAN ( CAN &&  )
default

Member Function Documentation

◆ GetTimestampBaseTime()

static uint64_t frc::CAN::GetTimestampBaseTime ( )
static

Reads the current value of the millisecond-resolution timer that CANData timestamps are based on.

Returns
Current value of timer used as a base time for CANData timestamps in milliseconds

◆ operator=()

CAN & frc::CAN::operator= ( CAN &&  )
default

◆ ReadPacketLatest()

bool frc::CAN::ReadPacketLatest ( int  apiId,
CANData data 
)

Read a CAN packet.

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

Parameters
apiIdThe API ID to read.
dataStorage for the received data.
Returns
True if the data is valid, otherwise false.

◆ ReadPacketNew()

bool frc::CAN::ReadPacketNew ( int  apiId,
CANData data 
)

Read a new CAN packet.

This will only return properly once per packet received. Multiple calls without receiving another packet will return false.

Parameters
apiIdThe API ID to read.
dataStorage for the received data.
Returns
True if the data is valid, otherwise false.

◆ ReadPacketTimeout()

bool frc::CAN::ReadPacketTimeout ( int  apiId,
int  timeoutMs,
CANData data 
)

Read a CAN packet.

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

Parameters
apiIdThe API ID to read.
timeoutMsThe timeout time for the packet
dataStorage for the received data.
Returns
True if the data is valid, otherwise false.

◆ StopPacketRepeating()

void frc::CAN::StopPacketRepeating ( int  apiId)

Stop a repeating packet with a specific ID.

This ID is 10 bits.

Parameters
apiIdThe API ID to stop repeating

◆ WritePacket()

void frc::CAN::WritePacket ( const uint8_t *  data,
int  length,
int  apiId 
)

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

This ID is 10 bits.

Parameters
dataThe data to write (8 bytes max)
lengthThe data length to write
apiIdThe API ID to write.

◆ WritePacketNoError()

int frc::CAN::WritePacketNoError ( const uint8_t *  data,
int  length,
int  apiId 
)

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

This ID is 10 bits.

Parameters
dataThe data to write (8 bytes max)
lengthThe data length to write
apiIdThe API ID to write.

◆ WritePacketRepeating()

void frc::CAN::WritePacketRepeating ( const uint8_t *  data,
int  length,
int  apiId,
int  repeatMs 
)

Write 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
dataThe data to write (8 bytes max)
lengthThe data length to write
apiIdThe API ID to write.
repeatMsThe period to repeat the packet at.

◆ WritePacketRepeatingNoError()

int frc::CAN::WritePacketRepeatingNoError ( const uint8_t *  data,
int  length,
int  apiId,
int  repeatMs 
)

Write 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
dataThe data to write (8 bytes max)
lengthThe data length to write
apiIdThe API ID to write.
repeatMsThe period to repeat the packet at.

◆ WriteRTRFrame()

void frc::CAN::WriteRTRFrame ( int  length,
int  apiId 
)

Write an RTR frame to the CAN device with a specific ID.

This ID is 10 bits. The length by spec must match what is returned by the responding device

Parameters
lengthThe length to request (0 to 8)
apiIdThe API ID to write.

◆ WriteRTRFrameNoError()

int frc::CAN::WriteRTRFrameNoError ( int  length,
int  apiId 
)

Write an RTR frame to the CAN device with a specific ID.

This ID is 10 bits. The length by spec must match what is returned by the responding device

Parameters
lengthThe length to request (0 to 8)
apiIdThe API ID to write.

Member Data Documentation

◆ kTeamDeviceType

constexpr HAL_CANDeviceType frc::CAN::kTeamDeviceType
staticconstexpr
Initial value:
=
@ HAL_CAN_Dev_kMiscellaneous
Definition: CANAPITypes.h:34

◆ kTeamManufacturer

constexpr HAL_CANManufacturer frc::CAN::kTeamManufacturer = HAL_CAN_Man_kTeamUse
staticconstexpr

The documentation for this class was generated from the following file: