Mikroelektronika MIKROE-742 데이터 시트

194

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

function CANSPIRead(var id: longint; var rd_data: array[8] of
byte; data_len: byte; 

var CAN_RX_MSG_FLAGS: byte): byte;

- 

0

if nothing is received 

- 

0xFF

if one of the Receive Buffers is full (message received) 

If at least one full Receive Buffer is found, it will be processed in the following way: 

- Message ID is retrieved and stored to location provided by the id parameter 
- Message data is retrieved and stored to a buffer provided by the 

rd_data

parameter 

- Message length is retrieved and stored to location provided by the 

data_len

parameter 

- Message flags are retrieved and stored to location provided by the    

CAN_RX_MSG_FLAGS

parameter 

Parameters:

- 

id

: message identifier storage address 

- 

rd_data

: data buffer (an array of bytes up to 8 bytes in length) 

- 

data_len

: data length storage address. 

- 

CAN_RX_MSG_FLAGS

: message flags storage address 

The CANSPI module must be in a mode in which receiving is possible. See
CANSPISetOperationMode.

The CANSPI routines are supported only by MCUs with the SPI module.

MCU has to be properly connected to mikroElektronika's CANSPI Extra Board
or similar hardware. See connection example at the bottom of this page.

// check the CANSPI module for received messages. If any was

received do something. 
var msg_rcvd, rx_flags, data_len: byte;

rd_data: 

array[8] of byte;

msg_id: longint;

...

CANSPISetOperationMode(CANSPI_MODE_NORMAL,0xFF);

// set NORMAL mode (CANSPI module must be in mode in which
receive is possible)

...

rx_flags := 0;
// clear message flags
if (msg_rcvd = CANSPIRead(msg_id, rd_data, data_len, rx_flags) 
begin