User manual

474
mikoC PRO for dsPIC
MikroElektronika
Software I²C Library
The mikroC PRO for dsPIC30/33 and PIC24 provides routines for implementing Software I²C communication. These
routines are hardware independent and can be used with any MCU. The Software I²C library enables you to use MCU
as Master in I²C communication. Multi-master mode is not supported.
Important :
- This library implements time-based activities, so interrupts need to be disabled when using Software I²C.
- All I²C Library functions are blocking-call functions (they are waiting for I²C clock line to become logical one).
- The pins used for the Software I²C communication should be connected to the pull-up resistors. Turning off the LEDs
connected to these pins may also be required.
- Every Software I²C library routine has its own counterpart in Hardware I²C library, except I2C_Repeated_Start.
Soft_I2C_Start is used instead of I2C_Repeated_Start.
- Working clock frequency of the Software I²C is 20kHz.
The following variable must be
dened in all projects using RS-485
Library:
Description : Example :
extern sbit Soft_I2C_Scl;
Soft I²C Clock line.
sbit Soft_I2C_Scl at RB11_bit;
extern sbit Soft_I2C_Sda;
Soft I²C Data line.
sbit Soft_I2C_Sda at RB12_bit;
extern sbit Soft_I2C_Scl_
Direction;
Direction of the Soft I²C Clock
pin.
sbit Soft_I2C_Scl_Direction at
TRISB11_bit;
extern sbit Soft_I2C_Sda_
Direction;
Direction of the Soft I²C Data
pin.
sbit Soft_I2C_Sda_Direction at
TRISB12_bit;
External dependencies of Software I²C Library
Library Routines
- Soft_I2C_Init
- Soft_I2C_Start
- Soft_I2C_Read
- Soft_I2C_Write
- Soft_I2C_Stop
- Soft_I2C_Break