MCP2515 Class Reference

A singleton class which implements the communication between the AVR and the MCP2515. More...

#include <mcp2515.h>

Inheritance diagram for MCP2515:

Public Member Functions
	MCP2515 (const MCP2515 &)=delete
void	SendMessage (CanMessage &message)
void	SetLoopback ()
void	SetNormal ()
void	Initialize (SPI::SPI *spi, uint16_t identifier)
Public Member Functions inherited from CAN
void	SetUpperLevel (void(*handler)(CanMessage &data))

Static Public Member Functions
static MCP2515 &	GetInstance ()

Private Member Functions
void	RequestToSend ()
void	WriteToRegister (uint8_t register_address, uint8_t byte)
void	ReadFromRegister (uint8_t register_address, uint8_t &byte)
void	Reset ()
void	BitModify (uint8_t register_address, uint8_t mask, uint8_t data)
void	ReadStatus (uint8_t &byte)
void	LoadTxFrame (CanMessage &message)
void	RxStatus (uint8_t &byte)
void	ReadRxFrame (CanMessage &message)
	MCP2515 ()

Private Attributes
SPI::SPI *	spi_driver
volatile bool	clear_to_send = true

Friends
void	MCP2515_INT ()

Additional Inherited Members
Protected Attributes inherited from CAN
void(*	upper_level )(CanMessage &data)

Detailed Description

A singleton class which implements the communication between the AVR and the MCP2515.

Throughout the documentation of this class, we will refer to the datasheet of the chip. This can be found at Microchips site

The SPI driver you are using must have meet the following criteria Size of output buffer > 14 bytes Size of input buffer > 11 bytes

Please note: This implementation only uses one recieve and transmit buffer. TX0 and RX0

Constructor & Destructor Documentation

MCP2515() [1/2]

MCP2515::MCP2515 ( )

inlineprivate

Initializer not used due to singleton

MCP2515() [2/2]

MCP2515::MCP2515 ( const MCP2515 &  )

delete

Because of singleton - makes sure its not copied etc.

Member Function Documentation

BitModify()

void MCP2515::BitModify ( uint8_t  register_address, uint8_t  mask, uint8_t  data  )

private

Modifies the given MCP2515 register with a bitmask. Please see MCP2515 datasheet page 66

Parameters

register_address	The address to the MCP2515 register
mask	Defines which bits to be modified
data	The byte to be written

GetInstance()

static MCP2515& MCP2515::GetInstance ( )

inlinestatic

A Singleton implementation of this class

Initialize()

void MCP2515::Initialize	(	SPI::SPI *	spi,
		uint16_t	identifier
	)

Initializes the MCP2515 driver.

Parameters

spi	The singleton instance of the SPI driver
identifier	The CAN identifier for this node

LoadTxFrame()

void MCP2515::LoadTxFrame ( CanMessage &  message )

private

Loads the transmit frame, i.e. sends the CAN data to the MCP2515

Parameters

message

The CAN_MESSAGE to be loaded into the TX frame

ReadFromRegister()

void MCP2515::ReadFromRegister ( uint8_t  register_address, uint8_t &  byte  )

private

Reads from the given MCP2515 register

Parameters

register_address	The address to the MCP2515 register
byte	The byte to be written into

ReadRxFrame()

void MCP2515::ReadRxFrame ( CanMessage &  message )

private

Reads the RxFrame, i.e. retrieves the recieved data

Parameters

message

The message to be written into

ReadStatus()

void MCP2515::ReadStatus ( uint8_t &  byte )

private

Gets the status byte from the MCP2515. Please see MCP2515 datasheet page 65, READ STATUS instruction

Parameters

byte	The byte to be written into

RequestToSend()

void MCP2515::RequestToSend ( )

private

Sends a RTS (Request to Send) signal to the MCP2515.

Reset()

void MCP2515::Reset ( )

private

Sends a reset command to the MCP2515 thorugh the SPI interace (hardware reset not connected). Will put the MCP2515 in config mode.

RxStatus()

void MCP2515::RxStatus ( uint8_t &  byte )

private

Gets the RxStatus byte from the MCP2515. Please see MCP2515 datasheet page 66, RX STATUS instruction

Parameters

byte	The byte to be written into

SendMessage()

void MCP2515::SendMessage ( CanMessage &  message )

virtual

Sends a CAN message

Parameters

message

The CAN message to be sent

Implements CAN.

SetLoopback()

void MCP2515::SetLoopback

(

)

Initiates the loopback mode of the MCP2515. Please consult the MCP2515 datasheet

SetNormal()

void MCP2515::SetNormal

(

)

Initiates the normal mode of the MCP2515. Please consult the MCP2515 datasheet

WriteToRegister()

void MCP2515::WriteToRegister ( uint8_t  register_address, uint8_t  byte  )

private

Writes to the given MCP2515 register

Parameters

register_address	The address to the MCP2515 register
byte	The byte to be written to the given register

Friends And Related Function Documentation

MCP2515_INT

void MCP2515_INT ( )

friend

The MCP2515 interrupt handler

Member Data Documentation

clear_to_send

volatile bool MCP2515::clear_to_send = true

private

Flag indicating if we can load the TX frame.

spi_driver

SPI::SPI* MCP2515::spi_driver

private

The SPI Driver the MCP2515 uses.

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

• lib/mcp2515/mcp2515.h
• lib/mcp2515/mcp2515.cpp