User manual

mikroC PRO for dsPIC
MikroElektronika
297
CANSPIRead
Prototype
unsigned short CANSPIRead(long *id, unsigned short *data, unsigned short
*datalen, unsigned short *CANSPI_RX_MSG_FLAGS);
Description 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 data parameter
- Message length is retrieved and stored to location provided by the dataLen parameter
- Message ags are retrieved and stored to location provided by the CANSPI_RX_MSG_FLAGS
parameter
Parameters - id: message identier address
- data: an array of bytes up to 8 bytes in length
- dataLen: data length address
- CANSPI_RX_MSG_FLAGS: message ags address. For message receive ags format refer to
CANSPI_RX_MSG_FLAGS constants. See CANSPI_RX_MSG_FLAGS constants.
Returns - 0 if nothing is received
- 0xFFFF if one of the Receive Buffers is full (message received)
Requires 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.
Example
// check the CANSPI module for received messages. If any was received do
something.
unsigned short msg_rcvd, rx_ags, data_len;
char data[8];
unsigned long msg_id;
...
CANSPISetOperationMode(_CANSPI_MODE_NORMAL,0xFF); // set
NORMAL mode (CANSPI module must be in mode in which receive is possible)
...
rx_ags = 0; // clear message
ags
if (msg_rcvd = CANSPIRead(msg_id, data, data_len, rx_ags)) {
...
}
Notes None.