#ifndef __IIC_H__
#define __IIC_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#define SET_SDA_OUT do{GPIOF->MODER &= (~(0x3 << 30)); \
GPIOF->MODER |= (0x1 << 30);}while(0)
#define SET_SDA_IN do{GPIOF->MODER &= (~(0x3 << 30));}while(0)
#define I2C_SCL_H do{GPIOF->BSRR |= (0x1 << 14);}while(0)
#define I2C_SCL_L do{GPIOF->BRR |= (0x1 << 14);}while(0)
#define I2C_SDA_H do{GPIOF->BSRR |= (0x1 << 15);}while(0)
#define I2C_SDA_L do{GPIOF->BRR |= (0x1 << 15);}while(0)
#define I2C_SDA_READ (GPIOF->IDR & (0x1 << 15))
void delay_us(void);
void i2c_init(void);
void i2c_start(void);
void i2c_stop(void);
void i2c_write_byte(unsigned char dat);
unsigned char i2c_read_byte(unsigned char ack);
unsigned char i2c_wait_ack(void);
void i2c_ack(void);
void i2c_nack(void);
#endif
#include "iic.h"
extern void printf(const char* fmt, ...);
void delay_us(void)
{
unsigned int i = 2000;
while(i--);
}
void i2c_init(void)
{
RCC->MP_AHB4ENSETR |= (0x1 << 5);
GPIOF->MODER &= (~(0xF << 28));
GPIOF->MODER |= (0x5 << 28);
GPIOF->OTYPER &= (~(0x3 << 14));
GPIOF->OSPEEDR |= (0xF << 28);
GPIOF->PUPDR &= (~(0xF << 28));
I2C_SCL_H;
I2C_SDA_H;
}
void i2c_start(void)
{
SET_SDA_OUT;
I2C_SCL_H;
delay_us();
I2C_SDA_H;
delay_us();
I2C_SDA_L;
I2C_SCL_L;
}
void i2c_stop(void)
{
SET_SDA_OUT;
I2C_SCL_L;
delay_us();
I2C_SDA_L;
delay_us();
I2C_SCL_H;
delay_us();
I2C_SDA_H;
delay_us();
}
void i2c_write_byte(unsigned char dat)
{
unsigned int i;
SET_SDA_OUT;
for(i=0;i<8;i++)
{
I2C_SCL_L;
delay_us();
if(dat & 0x80)
I2C_SDA_H;
else
I2C_SDA_L;
delay_us();
I2C_SCL_H;
delay_us();
delay_us();
dat <<= 1;
}
}
unsigned char i2c_read_byte(unsigned char ack)
{
unsigned int i;
unsigned char dat = 0;
SET_SDA_IN;
for(i=0;i<8;i++)
{
I2C_SCL_L;
delay_us();
delay_us();
I2C_SCL_H;
delay_us();
dat <<= 1;
if(I2C_SDA_READ)
dat |= 1;
else
dat |= 0;
delay_us();
}
if(!ack)
i2c_ack();
else
i2c_nack();
return dat;
}
unsigned char i2c_wait_ack(void)
{
I2C_SCL_L;
delay_us();
I2C_SDA_H;
delay_us();
SET_SDA_IN;
delay_us();
I2C_SCL_H;
delay_us();
if(I2C_SDA_READ)
return 1;
I2C_SCL_L;
return 0;
}
void i2c_ack(void)
{
SET_SDA_OUT;
I2C_SCL_L;
delay_us();
I2C_SDA_L;
delay_us();
I2C_SCL_H;
delay_us();
delay_us();
I2C_SCL_L;
}
void i2c_nack(void)
{
SET_SDA_OUT;
I2C_SCL_L;
delay_us();
I2C_SDA_H;
delay_us();
I2C_SCL_H;
delay_us();
delay_us();
I2C_SCL_L;
}
#ifndef __SI7006_H__
#define __SI7006_H__
#include "iic.h"
#define SI7006_SLAVE 0x40
void si7006_init(void);
unsigned short si7006_read_hum_data(unsigned char slave_addr, unsigned char reg_addr);
short si7006_read_temp_data(unsigned char slave_addr, unsigned char reg_addr);
#endif
#include "iic.h"
#include "si7006.h"
extern void delay_ms(unsigned int ms);
void si7006_init(void)
{
i2c_init();
i2c_start();
i2c_write_byte(SI7006_SLAVE << 1 | 0);
i2c_wait_ack();
i2c_write_byte(0xE6);
i2c_wait_ack();
i2c_write_byte(0x3A);
i2c_wait_ack();
i2c_stop();
}
unsigned short si7006_read_hum_data(unsigned char slave_addr, unsigned char reg_addr)
{
unsigned short dat;
unsigned char dat_h;
unsigned char dat_l;
i2c_start();
i2c_write_byte(slave_addr << 1 | 0);
i2c_wait_ack();
i2c_write_byte(reg_addr);
i2c_wait_ack();
i2c_start();
i2c_write_byte(slave_addr << 1 | 1);
i2c_wait_ack();
delay_ms(10);
dat_h = i2c_read_byte(0);
dat_l = i2c_read_byte(1);
i2c_stop();
dat = dat_h;
dat <<= 8;
dat |= dat_l;
return dat;
}
short si7006_read_temp_data(unsigned char slave_addr,
unsigned char reg_addr)
{
short dat;
unsigned char dat_h;
unsigned char dat_l;
i2c_start();
i2c_write_byte(slave_addr << 1 | 0);
i2c_wait_ack();
i2c_write_byte(reg_addr);
i2c_wait_ack();
i2c_start();
i2c_write_byte(slave_addr << 1 | 1);
i2c_wait_ack();
delay_ms(10);
dat_h = i2c_read_byte(0);
dat_l = i2c_read_byte(1);
i2c_stop();
dat = dat_h;
dat <<= 8;
dat |= dat_l;
return dat;
}
#include "iic.h"
#include "si7006.h"
extern void printf(const char *fmt, ...);
void delay_ms(int ms)
{
int i,j;
for(i = 0; i < ms;i++)
for (j = 0; j < 1800; j++);
}
int main()
{
short temp;
unsigned short hum;
si7006_init();
while(1)
{
hum = si7006_read_hum_data(SI7006_SLAVE,0xE5);
temp = si7006_read_temp_data(SI7006_SLAVE,0xE0);
printf("hum = %d\n",125*hum/65536 - 1);
printf("temp = %d\n",176*temp/65536 - 47);
}
return 0;
}