STM32F103固件库编程（6）—I2C
(一)I2C时序表
（二） STM32的I2C特性及架构
（三）寄存器映射
（四）代码（CV工程师）
#include "stm32f10x.h"
#include "bsp_usart.h"
#include "bsp_i2c.h"
uint8_t readData[10]={0};
uint8_t writeData[8]={4,5,6,7,8,9,10,11};
int main(void)
{
uint8_t i=0;
USART_Config();
printf("IIC\n");
I2C_EE_Config();
EEPROM_Byte_Write(11,55);
EEPROM_WaitForWriteEnd();
EEPROM_Byte_Write(12,52);
EEPROM_WaitForWriteEnd();
EEPROM_Page_Write(16,writeData,8);
EEPROM_WaitForWriteEnd();
EEPROM_Read(16,readData,8);
for(i=0;i<8;i++)
{
printf("%d ",readData[i]);
}
printf("111111111111111111");
while(1)
{
}
}
#ifndef __BSP_I2C_H
#define __BSP_I2C_H
#include "stm32f10x.h"
#define EEPROM_ADDR 0xA0
#define STM32_I2C_OWN_ADDR 0x5f
#define EEPROM_I2C I2C1
#define EEPROM_I2C_CLK RCC_APB1Periph_I2C1
#define EEPROM_I2C_APBxClkCmd RCC_APB1PeriphClockCmd
#define EEPROM_I2_BAUDRATE 400000
#define EEPROM_I2C_SCL_GPIO_CLK (RCC_APB2Periph_GPIOB)
#define EEPROM_I2C_SDA_GPIO_CLK (RCC_APB2Periph_GPIOB)
#define EEPROM_I2C_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
#define EEPROM_I2C_SCL_GPIO_PORT GPIOB
#define EEPROM_I2C_SCL_GPIO_PIN GPIO_Pin_6
#define EEPROM_I2C_SDA_GPIO_PORT GPIOB
#define EEPROM_I2C_SDA_GPIO_PIN GPIO_Pin_7
void I2C_EE_Config(void);
void EEPROM_Byte_Write(uint8_t addr,uint8_t data);
void EEPROM_Read(uint8_t addr,uint8_t *data,uint8_t numByteToRead);
void EEPROM_Page_Write(uint8_t addr,uint8_t *data,uint8_t numByteToWrite);
void EEPROM_WaitForWriteEnd(void);
#endif /* __BSP_I2C_H */
#include "bsp_i2c.h"
/**
* @brief IIC EEPROM 配置,工作参数配置
* @param 无
* @retval 无
*/
void I2C_EE_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
// 打开IIC GPIO的时钟
EEPROM_I2C_GPIO_APBxClkCmd(EEPROM_I2C_SCL_GPIO_CLK|EEPROM_I2C_SDA_GPIO_CLK, ENABLE);
// 打开IIC 外设的时钟
EEPROM_I2C_APBxClkCmd(EEPROM_I2C_CLK, ENABLE);
// 将IIC SCL的GPIO配置为推挽复用模式
GPIO_InitStructure.GPIO_Pin = EEPROM_I2C_SCL_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(EEPROM_I2C_SCL_GPIO_PORT, &GPIO_InitStructure);
// 将IIC SDA的GPIO配置为浮空输入模式
GPIO_InitStructure.GPIO_Pin = EEPROM_I2C_SDA_GPIO_PIN;
GPIO_Init(EEPROM_I2C_SDA_GPIO_PORT, &GPIO_InitStructure);
// 配置IIC的工作参数
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable ;//使能应答
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit ;//使用7位地址模式
I2C_InitStructure.I2C_ClockSpeed = EEPROM_I2_BAUDRATE; //配置SCL时钟频率
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2 ;
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C ;
I2C_InitStructure.I2C_OwnAddress1 = STM32_I2C_OWN_ADDR; //这是STM32 IIC自身设备地址，只要是总线上唯一即可
I2C_Init(EEPROM_I2C,&I2C_InitStructure);
// 使能串口
I2C_Cmd (EEPROM_I2C, ENABLE);
}
//向EEPROM写入一个字节
void EEPROM_Byte_Write(uint8_t addr,uint8_t data)
{
//产生起始信号
I2C_GenerateSTART(EEPROM_I2C,ENABLE);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_MODE_SELECT) == ERROR);
//EV5事件被检测到，发送设备地址
I2C_Send7bitAddress(EEPROM_I2C,EEPROM_ADDR,I2C_Direction_Transmitter);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ) == ERROR);
//EV6事件被检测到，发送要操作的存储单元地址
I2C_SendData (EEPROM_I2C,addr);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_TRANSMITTING ) == ERROR);
//EV8事件被检测到，发送要存储的数据
I2C_SendData (EEPROM_I2C,data);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_TRANSMITTED ) == ERROR);
//数据传输完成
I2C_GenerateSTOP(EEPROM_I2C,ENABLE);
}
//向EEPROM写入多个字节（页写入），每次写入不能超过8个字节
void EEPROM_Page_Write(uint8_t addr,uint8_t *data,uint8_t numByteToWrite)
{
//产生起始信号
I2C_GenerateSTART(EEPROM_I2C,ENABLE);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_MODE_SELECT) == ERROR);
//EV5事件被检测到，发送设备地址
I2C_Send7bitAddress(EEPROM_I2C,EEPROM_ADDR,I2C_Direction_Transmitter);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ) == ERROR);
//EV6事件被检测到，发送要操作的存储单元地址
I2C_SendData (EEPROM_I2C,addr);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_TRANSMITTING ) == ERROR);
while(numByteToWrite)
{
//EV8事件被检测到，发送要存储的数据
I2C_SendData (EEPROM_I2C,*data);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_TRANSMITTED ) == ERROR);
data++;
numByteToWrite--;
}
//数据传输完成
I2C_GenerateSTOP(EEPROM_I2C,ENABLE);
}
//从EEPROM读取数据
void EEPROM_Read(uint8_t addr,uint8_t *data,uint8_t numByteToRead)
{
//产生起始信号
I2C_GenerateSTART(EEPROM_I2C,ENABLE);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_MODE_SELECT) == ERROR);
//EV5事件被检测到，发送设备地址
I2C_Send7bitAddress(EEPROM_I2C,EEPROM_ADDR,I2C_Direction_Transmitter);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ) == ERROR);
//EV6事件被检测到，发送要操作的存储单元地址
I2C_SendData (EEPROM_I2C,addr);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_TRANSMITTING ) == ERROR);
//第二次起始信号
//产生起始信号
I2C_GenerateSTART(EEPROM_I2C,ENABLE);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_MODE_SELECT) == ERROR);
//EV5事件被检测到，发送设备地址
I2C_Send7bitAddress(EEPROM_I2C,EEPROM_ADDR,I2C_Direction_Receiver);
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED ) == ERROR);
while(numByteToRead)
{
if(numByteToRead == 1)
{
//如果为最后一个字节
I2C_AcknowledgeConfig (EEPROM_I2C,DISABLE);
}
//EV7事件被检测到
while(I2C_CheckEvent(EEPROM_I2C,I2C_EVENT_MASTER_BYTE_RECEIVED ) == ERROR);
//EV7事件被检测到，即数据寄存器有新的有效数据
*data = I2C_ReceiveData(EEPROM_I2C);
data++;
numByteToRead--;
}
//数据传输完成
I2C_GenerateSTOP(EEPROM_I2C,ENABLE);
//重新配置ACK使能，以便下次通讯
I2C_AcknowledgeConfig (EEPROM_I2C,ENABLE);
}
//等待EEPROM内部时序完成
void EEPROM_WaitForWriteEnd(void)
{
do
{
//产生起始信号
I2C_GenerateSTART(EEPROM_I2C,ENABLE);
while(I2C_GetFlagStatus (EEPROM_I2C,I2C_FLAG_SB) == RESET);
//EV5事件被检测到，发送设备地址
I2C_Send7bitAddress(EEPROM_I2C,EEPROM_ADDR,I2C_Direction_Transmitter);
}
while(I2C_GetFlagStatus (EEPROM_I2C,I2C_FLAG_ADDR) == RESET );
//EEPROM内部时序完成传输完成
I2C_GenerateSTOP(EEPROM_I2C,ENABLE);
}
（五）问题
1.高阻态咋回事
2.CCR寄存器——时钟频率的计算
