User manual

290
mikoC PRO for dsPIC
MikroElektronika
CANSPI Library
The SPI module is available with a number of the dsPIC30/33 and PIC24 MCUs. The mikroC PRO for dsPIC30/33
and PIC24 provides a library (driver) for working with mikroElektronika's CANSPI Add-on boards (with MCP2515 or
MCP2510) via SPI interface.
In the mikroC PRO for dsPIC30/33 and PIC24, each routine of the CAN library has its own CANSPI counterpart with
identical syntax. For more information on Controller Area Network, consult the CAN Library. Note that an effective
communication speed depends on SPI and certainly is slower than "real" CAN.
Important :
- Consult the CAN standard about CAN bus termination resistance.
- An effective CANSPI communication speed depends on SPI and certainly is slower than “real” CAN.
- The library uses the SPI module for communication. User must initialize appropriate SPI module before using
the CANSPI Library.
- For MCUs with multiple SPI modules it is possible to initialize both of them and then switch by using the
SPI_Set_Active routine.
- Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before
utilizing this library.
Library Dependency Tree
External dependencies of CANSPI Library
The following variables must
be dened in all projects using
CANSPI Library:
Description : Example :
extern sfr sbit CanSpi_CS;
Chip Select line.
sbit CanSpi_CS at
RF0_bit;
extern sfr sbit
CanSpi_Rst;
Reset line.
sbit CanSpi_Rst at
RF1_bit;
extern sfr sbit
CanSpi_CS_Direction;
Direction of the Chip Select pin.
sbit
CanSpi_CS_Direction
at TRISF0_bit;
extern sfr sbit
CanSpi_Rst_Direction;
Direction of the Reset pin.
sbit
CanSpi_Rst_Direction
at TRISF1_bit;