IIC初始化代码
时间: 2023-07-02 19:15:10 浏览: 55
以下是基于STM32的IIC初始化代码示例:
```c
#include "stm32f10x.h"
#define I2C_SCL_PIN GPIO_Pin_6
#define I2C_SDA_PIN GPIO_Pin_7
#define I2C_PORT GPIOB
void I2C_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = I2C_SCL_PIN | I2C_SDA_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(I2C_PORT, &GPIO_InitStructure);
}
void I2C_Init(void)
{
I2C_InitTypeDef I2C_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = 0x00;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 100000;
I2C_Cmd(I2C1, ENABLE);
I2C_Init(I2C1, &I2C_InitStructure);
}
void I2C_Start(void)
{
GPIO_SetBits(I2C_PORT, I2C_SCL_PIN | I2C_SDA_PIN);
GPIO_ResetBits(I2C_PORT, I2C_SDA_PIN);
GPIO_ResetBits(I2C_PORT, I2C_SCL_PIN);
}
void I2C_Stop(void)
{
GPIO_ResetBits(I2C_PORT, I2C_SCL_PIN);
GPIO_ResetBits(I2C_PORT, I2C_SDA_PIN);
GPIO_SetBits(I2C_PORT, I2C_SCL_PIN | I2C_SDA_PIN);
}
void I2C_SendByte(uint8_t byte)
{
uint8_t i;
for(i = 0; i < 8; i++)
{
if(byte & 0x80)
{
GPIO_SetBits(I2C_PORT, I2C_SDA_PIN);
}
else
{
GPIO_ResetBits(I2C_PORT, I2C_SDA_PIN);
}
GPIO_SetBits(I2C_PORT, I2C_SCL_PIN);
GPIO_ResetBits(I2C_PORT, I2C_SCL_PIN);
byte <<= 1;
}
}
uint8_t I2C_ReceiveByte(void)
{
uint8_t i, byte = 0;
GPIO_SetBits(I2C_PORT, I2C_SDA_PIN);
for(i = 0; i < 8; i++)
{
byte <<= 1;
GPIO_SetBits(I2C_PORT, I2C_SCL_PIN);
if(GPIO_ReadInputDataBit(I2C_PORT, I2C_SDA_PIN))
{
byte |= 0x01;
}
GPIO_ResetBits(I2C_PORT, I2C_SCL_PIN);
}
return byte;
}
void I2C_WriteByte(uint8_t address, uint8_t reg, uint8_t value)
{
I2C_Start();
I2C_SendByte(address << 1);
I2C_SendByte(reg);
I2C_SendByte(value);
I2C_Stop();
}
uint8_t I2C_ReadByte(uint8_t address, uint8_t reg)
{
uint8_t value;
I2C_Start();
I2C_SendByte(address << 1);
I2C_SendByte(reg);
I2C_Start();
I2C_SendByte((address << 1) | 0x01);
value = I2C_ReceiveByte();
I2C_Stop();
return value;
}
void I2C_ReadBuffer(uint8_t address, uint8_t reg, uint8_t *buffer, uint8_t length)
{
uint8_t i;
I2C_Start();
I2C_SendByte(address << 1);
I2C_SendByte(reg);
I2C_Start();
I2C_SendByte((address << 1) | 0x01);
for(i = 0; i < length; i++)
{
if(i == length - 1)
{
buffer[i] = I2C_ReceiveByte();
}
else
{
buffer[i] = I2C_ReceiveByte() | 0x80;
}
}
I2C_Stop();
}
```
在以上代码中,我们首先调用了`I2C_GPIO_Config()`函数对IIC通信所需的GPIO引脚进行配置,然后调用`I2C_Init()`函数对IIC总线进行初始化。
在进行IIC通信时,我们可以调用`I2C_Start()`和`I2C_Stop()`函数分别发送START和STOP信号,使用`I2C_SendByte()`函数发送一个字节的数据,使用`I2C_ReceiveByte()`函数接收一个字节的数据,并使用`I2C_ReadByte()`和`I2C_ReadBuffer()`函数读取多个字节的数据。