////////////////////////////////////////////////////////////
// Write command to the MCP2515
////////////////////////////////////////////////////////////
void can_write_cmd(char cmd){
spi_init_buffer();
spi_load_byte(cmd);
spi_exchange();
spi_wait_for_completion();
}
////////////////////////////////////////////////////////////
// Write byte <data> to register with address <reg>
////////////////////////////////////////////////////////////
void can_write_reg(char address, char data){
spi_init_buffer();
spi_load_byte(c2515Write);
spi_load_byte(address);
spi_load_byte(data);
spi_exchange();
spi_wait_for_completion();
}
////////////////////////////////////////////////////////////
// Software reset in case the reset pin is not available
////////////////////////////////////////////////////////////
void can_reset(){
// Reset the SPI buffer
spi_init_buffer();
// Load and TX command
spi_load_byte(c2515Reset);
spi_exchange();
spi_wait_for_completion();
return;
}
////////////////////////////////////////////////////////////
// Write <data> in <address> using <mask>
////////////////////////////////////////////////////////////
void can_write_bits(char address, char data, char mask){
spi_init_buffer();
spi_load_byte(c2515BitMod);
spi_load_byte(address);
spi_load_byte(mask);
spi_load_byte(data);
spi_exchange();
spi_wait_for_completion();
}
////////////////////////////////////////////////////////////
// Wait for the completion of the SPI exchange
// Skipped when running in debug mode.
////////////////////////////////////////////////////////////
void spi_wait_for_completion(){
#ifdef DBG_COMPILE
#warning "Debug build, spi_wait_for_completion will return immediately"
return;
#endif
while (spi_counter){
};
spi_init_buffer();
}
void can_read_status(){
// Reset the SPI buffer
spi_init_buffer();
// Load and TX command
spi_load_byte(c2515Status);
spi_load_byte(0x00);
spi_exchange();
spi_wait_for_completion();
serial_printf("Status = ");
serial_print_hex(spi_get_byte(1));
return;
}
////////////////////////////////////////////////////////////
// Read the contents of the register at <address>
////////////////////////////////////////////////////////////
char can_read_reg(char address){
spi_init_buffer();
// Read command
spi_load_byte(c2515Read);
// Register address
spi_load_byte(address);
// Expect one byte answer
spi_load_zeros(0x01);
// Start the transfer
spi_exchange();
spi_wait_for_completion();
return spi_get_byte(2);
}
////////////////////////////////////////////////////////////
// Read several bytes from the other device into the
// data buffer. Used when you're talking through a
// one-wire SPI interface (e.g. for nRF2401).
// ! The data output pin should be disabled when this
// ! routine is called.
////////////////////////////////////////////////////////////
void spi_read(char nr_of_bytes){
// Buffer init
spi_init_buffer();
// Set the number of bytes we want to read
spi_load_zeros(nr_of_bytes);
// Disable the output pin
//spi_do_tris = 1;
// Do the exchange
spi_exchange();
// Wait for completion
spi_wait_for_completion();
// Enable the output pin again
//spi_do_tris = 0;
return;
}
