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soft_i2c.c
191 lines (161 loc) · 2.61 KB
/
soft_i2c.c
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#include <xc.h>
#include <stdio.h>
#include <stdlib.h>
#include "soft_i2c.h"
#define _XTAL_FREQ 64000000
/**
* Set SDA
*/
void I2C_SDA_SET() {
LATC4 = 1;
}
/**
* Clear SDA
*/
void I2C_SDA_CLEAR() {
LATC4 = 0;
}
/**
* Set SDA IN
*/
void I2C_SDA_IN_SET() {
TRISC4 = 1;
}
/**
* Set SDA OUT
*/
void I2C_SDA_OUT_SET() {
TRISC4 = 0;
}
/**
* Set SCL
*/
void I2C_SCL_SET() {
LATC3 = 1;
}
/**
* Cleat SCL
*/
void I2C_SCL_CLEAR() {
LATC3 = 0;
}
/**
* Set SCL OUT
*/
void I2C_SCL_OUT_SET() {
TRISC3 = 0;
}
/**
* Reat SDA value
* @return SDA value
*/
char I2C_SDA_READ() {
return PORTCbits.RC4;
}
/**
* Soft I2C library initialization
*/
void I2C_Init() {
I2C_SDA_OUT_SET();
I2C_SCL_OUT_SET();
I2C_SCL_SET();
I2C_SDA_SET();
__delay_ms(10);
}
/**
* I2C start condition
*/
void I2C_Start() {
I2C_SDA_OUT_SET();
//I2C_SCL_OUT_SET();
I2C_SDA_SET();
I2C_SCL_SET();
__delay_us(20);
I2C_SDA_CLEAR();
__delay_us(20);
I2C_SCL_CLEAR();
__delay_us(20);
}
/**
* I2C stop condition
*/
void I2C_Stop() {
I2C_SDA_OUT_SET();
//I2C_SCL_OUT_SET();
I2C_SCL_SET();
__delay_us(20);
I2C_SDA_SET();
__delay_us(20);
}
/**
* I2C write given byte
* @param byt
*/
void I2C_Write_Byte(char byt) {
char i;
I2C_SDA_OUT_SET();
//I2C_SCL_OUT_SET();
for (i = 0; i < 8; i++) {
if (byt & 0x80) {
I2C_SDA_SET();
__delay_us(20);
} else {
I2C_SDA_CLEAR();
__delay_us(20);
}
I2C_SCL_SET();
__delay_us(20);
I2C_SCL_CLEAR();
__delay_us(20);
byt <<= 1;
}
I2C_SDA_IN_SET();
I2C_SCL_SET();
__delay_us(20);
I2C_SCL_CLEAR();
__delay_us(20);
I2C_SDA_OUT_SET();
//I2C_SCL_OUT_SET();
}
/**
* I2C read byte
* @param ack
* @return
*/
char I2C_Read_Byte(char ack) {
char i;
char val = 0;
I2C_SDA_IN_SET();
//I2C_SCL_OUT_SET();
for (i = 0; i < 8; i++) {
if (i != 0) {
val <<= 1;
}
I2C_SCL_SET();
__delay_us(20);
if (I2C_SDA_READ() != 0) {
val |= 0x01;
} else {
val &= 0xFE;
}
__delay_us(10);
I2C_SCL_CLEAR();
__delay_us(20);
}
I2C_SDA_OUT_SET();
//I2C_SCL_OUT_SET();
if (ack) {
I2C_SDA_CLEAR();
I2C_SCL_SET();
__delay_us(20);
I2C_SCL_CLEAR();
__delay_us(20);
} else {
I2C_SDA_SET();
I2C_SCL_SET();
__delay_us(20);
I2C_SCL_CLEAR();
__delay_us(20);
}
return val;
}