====== CAN-Functions ======

====The can_t Structure====

CAN communication between the used CAN boards is (on the programming
level) accessed through the use of a structure named can_t which is defined in
"can.h". The structure can_t consists of variables that can be written to prepare a
message for sending or read to process a received message. Here is an overview
of the variables of this structure:

<code c>
Structure  can_t:

	uint32_t        id: //  message  ID

	struct flags
	int rtr: //  remote-transmit-request-frame
	int extended: //  extended  ID  ?

	uint8_t length: //  number  of  data  bytes
	uint8_t data[8]: //  message  data
</code>

====Functions for CAN Communication====

The header file "can.h" declares various functions necessary for CAN communi-
cation. The CAN library is open source. The following functions are sufficient
for basic communication:

**Initialization of the CAN interface, setting of the baud rate:**
<code c>
extern    bool can_init(can_bitrate_t  bitrate);

//  Check  if  a  CAN  message  has  been  received  (function  returns  TRUE  or  FALSE):

extern    bool can_check_message(void);

//  Retrieving  a  message  out  of  the  receive  buffers  of  the  CAN  controller:

extern    uint8_t      can_get_message(can_t  *msg);

//  Sending  a  message  over  the  CAN  Bus:

extern    uint8_t      can_send_message(const  can_t  *msg);
</code>