Transport layer over CAN bus

Classes
struct	CanFrame
Defines
#define	MAX_DROPPING_SOURCE   20
Typedefs
typedef int(*	AsebaCanIntVoidFP )()
typedef void(*	AsebaCanSendFrameFP )(const CanFrame *frame)
typedef void(*	AsebaCanVoidVoidFP )()
Functions
void	AsebaCanFlushQueue (void)
void	AsebaCanFrameReceived (const CanFrame *frame)
void	AsebaCanFrameSent ()
uint16	AsebaCanGetMinMultipleOfHeight (uint16 v)
void	AsebaCanInit (uint16 id, AsebaCanSendFrameFP sendFrameFP, AsebaCanIntVoidFP isFrameRoomFP, AsebaCanVoidVoidFP receivedPacketDroppedFP, AsebaCanVoidVoidFP sentPacketDroppedFP, CanFrame *sendQueue, size_t sendQueueSize, CanFrame *recvQueue, size_t recvQueueSize)
uint16	AsebaCanRecv (uint8 *data, size_t size, uint16 *source)
uint16	AsebaCanRecvBufferEmpty (void)
void	AsebaCanRecvFreeQueue (void)
static void	AsebaCanRecvQueueFreeFrames (uint16 id)
static void	AsebaCanRecvQueueGarbageCollect ()
static uint16	AsebaCanRecvQueueGetMaxUsedFrames ()
static uint16	AsebaCanRecvQueueGetMinFreeFrames ()
uint16	AsebaCanSend (const uint8 *data, size_t size)
static uint16	AsebaCanSendQueueGetFreeFrames ()
static uint16	AsebaCanSendQueueGetUsedFrames ()
static void	AsebaCanSendQueueInsert (uint16 canid, const uint8 *data, size_t size)
static void	AsebaCanSendQueueToPhysicalLayer ()
uint16	AsebaCanSendSpecificSource (const uint8 *data, size_t size, uint16 source)
void	AsebaIdle (void)
uint16	AsebaShouldDropPacket (uint16 source, const uint8 *data)
Variables
static uint16	dropping [MAX_DROPPING_SOURCE]

---

Detailed Description

This layer is able to transmit messages of arbitrary length (up to the available amount of memory) over a serie of 8 bytes CAN frames. If the message is under 8 bytes, the layer uses a single frame.

The layer does not uses acknowledgment, instead it trusts the CAN checksum mechanism to ensure that other nodes on the CAN bus received the data correctly.

---

Define Documentation

#define MAX_DROPPING_SOURCE   20

Definition at line 327 of file can-net.c.

---

Typedef Documentation

typedef int(* AsebaCanIntVoidFP)()

Pointer to a void function returning int

Definition at line 63 of file can-net.h.

typedef void(* AsebaCanSendFrameFP)(const CanFrame *frame)

Pointer to a function that sends a CAN frame (max 8 bytes)

Definition at line 66 of file can-net.h.

typedef void(* AsebaCanVoidVoidFP)()

Pointer to a void function

Definition at line 60 of file can-net.h.

---

Function Documentation

void AsebaCanFlushQueue

(

void

)

Wait until the send queue is empty

void AsebaCanFrameReceived

(

const CanFrame *

frame

)

Data layer should call this function when a new CAN frame (max 8 bytes) is available

void AsebaCanFrameSent

(

)

Data layer should call this function when the CAN frame (max 8 bytes) was sent successfully

uint16 AsebaCanGetMinMultipleOfHeight

(

uint16

v

)

Returned the minimum number of multiple of height to fit v

Definition at line 49 of file can-net.c.

void AsebaCanInit	(	uint16	id,
		AsebaCanSendFrameFP	sendFrameFP,
		AsebaCanIntVoidFP	isFrameRoomFP,
		AsebaCanVoidVoidFP	receivedPacketDroppedFP,
		AsebaCanVoidVoidFP	sentPacketDroppedFP,
		CanFrame *	sendQueue,
		size_t	sendQueueSize,
		CanFrame *	recvQueue,
		size_t	recvQueueSize
	)

Init the CAN connection.

Parameters:

	id	the identifier of this node on the aseba CAN network
	sendFrameFP	pointer to a function that sends CAN frames to the data layer
	isFrameRoomFP	pointer to a function that returns if the data layer is ready to send frames
	receivedPacketDroppedFP	pointer to a function that is called when a received packet has been dropped, for various reasons but mostly related to insufficient memory
	sentPacketDroppedFP	pointer to a function that is called when a sent packet has been dropped (AsebaCanSend() returned 0), for various reasons but mostly related to insufficient memory
	sendQueue	pointer to send queue data
	sendQueueSize	number of frame in sendQueue
	recvQueue	pointer to receive queue data
	recvQueueSize	number of frame in recvQueue

uint16 AsebaCanRecv	(	uint8 *	data,
		size_t	size,
		uint16 *	source
	)

Copy data from a received packet to the caller-provided buffer. Remove the packet from the reception queue afterwards.

Parameters:

	data	pointer where to copy the data
	size	makimum number of byte to copy. Actual number of byte might be smaller if packet was smaller. If packet was bigger, the rest of the data are dropped.
	source	the identifier of the source of the received packet

Returns:

the amount of data copied. 0 if no data were available.

uint16 AsebaCanRecvBufferEmpty

(

void

)

Return true if the recv buffer is empty, false otherwise

void AsebaCanRecvFreeQueue

(

void

)

Free everything in the Rx queue. Warning, this is a low-level function which should only be called if the underlaying CAN driver is disabled.

static void AsebaCanRecvQueueFreeFrames

(

uint16

id

)

[static]

Free frames associated with an id in the reception queue

Definition at line 151 of file can-net.c.

static void AsebaCanRecvQueueGarbageCollect

(

)

[static]

Readjust the fifo pointers

Definition at line 135 of file can-net.c.

static uint16 AsebaCanRecvQueueGetMaxUsedFrames

(

)

[static]

Returned the maximum number of used frames in the reception queue

Definition at line 117 of file can-net.c.

static uint16 AsebaCanRecvQueueGetMinFreeFrames

(

)

[static]

Returned the minimum number of free frames in the reception queue

Definition at line 129 of file can-net.c.

uint16 AsebaCanSend	(	const uint8 *	data,
		size_t	size
	)

Send data as an aseba packet.

Parameters:

	data	pointer to the data to send
	size	amount of data to send

Returns:

1 on success, 0 on failure

static uint16 AsebaCanSendQueueGetFreeFrames

(

)

[static]

Returned the number of free frames in the send queue

Definition at line 71 of file can-net.c.

static uint16 AsebaCanSendQueueGetUsedFrames

(

)

[static]

Returned the number of used frames in the send queue

Definition at line 58 of file can-net.c.

static void AsebaCanSendQueueInsert	(	uint16	canid,
		const uint8 *	data,
		size_t	size
	)			[static]

Insert a frame in the send queue, do not check for overwrite

Definition at line 77 of file can-net.c.

static void AsebaCanSendQueueToPhysicalLayer

(

)

[static]

Send frames in send queue to physical layer until it is full

Definition at line 92 of file can-net.c.

uint16 AsebaCanSendSpecificSource	(	const uint8 *	data,
		size_t	size,
		uint16	source
	)

Send data as an aseba packet.

Parameters:

	data	pointer to the data to send
	size	amount of data to send
	source	identifier to use as source

Returns:

1 on success, 0 on failure

void AsebaIdle

(

void

)

Busy wait until the can buffer has room. At worst, can be an empty function

Definition at line 167 of file main.c.

uint16 AsebaShouldDropPacket	(	uint16	source,
		const uint8 *	data
	)

Return true if VM will ignore the packet, false otherwise

Definition at line 172 of file main.c.

---

Variable Documentation

uint16 dropping[MAX_DROPPING_SOURCE] [static]

Definition at line 328 of file can-net.c.