can_library.c File Reference

#include "can_library.h"
#include <util/atomic.h>

Functions
uint8_t	can_getRxBufferLength ()
	Returns the number of messages in the buffer. More...
int	canbuf_add (canMessage **m)
int	canbuf_remove (canMessage *m)
int8_t	can_hasFreeTxBuffer ()
	Check if there are ant free transmitting MOBs. More...
void	can_enableTransciever ()
void	can_disableTransciever ()
uint8_t	can_init ()
	Initialize the bus and activate hardware. More...
void	can_close ()
	Disable driver & hardware. More...
uint8_t	can_sendMessage (canMessage *m)
	Sends a can message. More...
int8_t	can_getMessage (canMessage *m)
	Gets a can message from the reception buffer. More...
	SIGNAL (CAN_TOVF_vect)
	SIGNAL (CAN_INT_vect)

Variables
volatile unsigned char	msg_received = 0
volatile uint32_t	cantimecounter = 0
#define	RING_SIZE   32
volatile uint8_t	ring_head
volatile uint8_t	ring_tail
volatile canMessage	ring_data [RING_SIZE]

Detailed Description

CAN library for AtMega64C1. (license: GPLv2 or LGPLv2.1)

Version

0.1

Author

Tuomas Huuki tuoma.nosp@m.s.hu.nosp@m.uki@p.nosp@m.roxi.nosp@m.mia.f.nosp@m.i

Copyright

2014 Tuomas Huuki / proximia.fi

See also

http://proximia.fi

Function Documentation

can_close()

void can_close

(

)

Disable driver & hardware.

Disabled the driver and the transciever if the option has been configured.

can_getMessage()

int8_t can_getMessage

(

canMessage *

m

)

Gets a can message from the reception buffer.

Parameters

m	Pointer to message.

Return values

-1	No message in buffer.
n	Number of messages in buffer.

Retrieves a message from the internal circular buffer and returns the amount of messages left in the buffer OR CAN_BUFFEREMPTY if the buffer is empty. You may use either:

if(can_getMessage(&m) != CAN_BUFFEREMPTY){
   // Process one message.
}

or

while(can_getMessage(&m) != CAN_BUFFEREMPTY){
  // Process until buffer empty.
}

depending on your implementation, buffer length and bus speed.

can_getRxBufferLength()

uint8_t can_getRxBufferLength

(

)

Returns the number of messages in the buffer.

Returns

n Number of messages in buffer.

can_hasFreeTxBuffer()

int8_t can_hasFreeTxBuffer

(

)

Check if there are ant free transmitting MOBs.

Return values

-1	No buffers
n	free buffer.

can_init()

uint8_t can_init

(

)

Initialize the bus and activate hardware.

Return values

0	Init/autobaud failure.
1	Init/autobaud success.

Initializes the driver, speed and also activates the transciever if the option has been configured.

#define CAN_BAUDRATE    250 // Use 0 for autobaud.

can_sendMessage()

uint8_t can_sendMessage

(

canMessage *

m

)

Sends a can message.

Parameters

m	Pointer to a canMessage object that has been configured.

Return values

0	Message NOT sent.
1	Message sent.

Sends a canmessage with the configured id and data. Usage example:

canMessage m;
m.mesid = MTYPESDOSLAVE | nodeid;
m.data[1] = BL_VERSION_MAJOR;
m.data[2] = BL_VERSION_MINOR;
m.data[3] = BL_VERSION_BUILD;
m.data[4] = boot_signature_byte_get(0x00);
m.data[5] = boot_signature_byte_get(0x02);
m.data[6] = boot_signature_byte_get(0x04);
m.data[7] = NODETYPEDEF;
m.length = 8;
// Blocking (use return value for information and resend on next loop for non blocking operation).
while(!can_sendMessage(&m));