[应用相关] STM32外设驱动篇——AT24C02（I2C接口）

#include "stm32f10x.h"

#include "stm32f10x_i2c.h"

#include <stdio.h>



void I2C2_Init(I2C_InitTypeDef* I2C_InitStruct)

{

        GPIO_InitTypeDef GPIO_InitStruct; 



        RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);        

        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);         

        

        /* 配置IO管脚 */

        GPIO_InitStruct.GPIO_Pin =  GPIO_Pin_10 | GPIO_Pin_11;            

        GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;            

        GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_OD;

        GPIO_Init(GPIOB, &GPIO_InitStruct); 

   

           I2C_Init(I2C2, I2C_InitStruct);

        I2C_Cmd(I2C2, ENABLE);

        

        // 配置NVIC

/*        NVIC_InitStructure.NVIC_IRQChannel = I2C2_EV_IRQn   ;                                //I2C事件中断

        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;        //抢占优先级1 

        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;                        //子优先级2 

        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                                        //使能中断通道

        NVIC_Init(&NVIC_InitStructure);                                                            //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器 */



        //I2C_ITConfig(I2C2, I2C_IT_EVT, ENABLE); //打开事件中断

}



/* i2c 写一个字节*/

/* Byte Write */

void I2C2_WriteByte(uint8_t DeviceAddress, uint8_t MemoryAddress, uint8_t Data)

{

        while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));           //等待I2C空闲 



        //start

        I2C_GenerateSTART(I2C2, ENABLE);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT) != SUCCESS ); 

        

        //device address

        I2C_Send7bitAddress(I2C2, DeviceAddress, I2C_Direction_Transmitter); //写模式

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) != SUCCESS );         

        //printf("address over\r\n") ; 



        //memory address

        I2C_SendData(I2C2, MemoryAddress);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED) != SUCCESS ); 

                        

        //data

           I2C_SendData(I2C2, Data);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED) != SUCCESS );         



        //stop

        I2C_GenerateSTOP(I2C2, ENABLE); 

}



/* i2c 读一个字节*/

/* Random Read */

uint8_t I2C2_ReadByte(uint8_t DeviceAddress, uint8_t MemoryAddress)

{

        uint8_t        Data;

        

        while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));           //等待I2C空闲  

        //start

        I2C_GenerateSTART(I2C2, ENABLE);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT) != SUCCESS ); //ev5 



        //device address

        I2C_Send7bitAddress(I2C2, DeviceAddress, I2C_Direction_Transmitter);  //写模式

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) != SUCCESS );         //ev6 

         

        //memory address

        I2C_SendData(I2C2,  MemoryAddress);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED) != SUCCESS ) ; 

                                                                                                                                                  

        //start

        I2C_GenerateSTART(I2C2, ENABLE);

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT) != SUCCESS ) ;         



        //device address

        I2C_Send7bitAddress(I2C2, DeviceAddress, I2C_Direction_Receiver); //读模式

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED) != SUCCESS ) ;

        

        /* 按照manual的图273，先读取数据，关闭ACK应答，最后发出STOP*/           

        while( I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED) != SUCCESS );         /* 等待读取事件，再读取数据 */

           Data = I2C_ReceiveData(I2C2); 

        I2C_AcknowledgeConfig(I2C2, DISABLE); //关闭应答和停止条件产生  

        printf("received\r\n");

        I2C_GenerateSTOP(I2C2, ENABLE); 

        

        I2C_AcknowledgeConfig(I2C2, ENABLE); 



        return Data;

}

#include "stm32f10x.h"

#include "stm32f10x_i2c.h"

#include "i2c.h"

#include "delay.h"

#include <stdio.h>



/* 从AT24CXX的指定地址开始读出一个字节 */

uint8_t AT24CXX_ReadByte(uint8_t ReadAddr)

{

        return I2C2_ReadByte(0xA0, ReadAddr);

}  



/* 向AT24CXX的指定地址开始写入一个字节 */

void AT24CXX_WriteByte(uint8_t WriteAddr, uint8_t Data)

{

        I2C2_WriteByte(0xA0, WriteAddr, Data);

}



void AT24CXX_test(void)

{

        uint8_t i;

           I2C_InitTypeDef I2C_InitStructure; 



        I2C_InitStructure.I2C_ClockSpeed         =  200000;           //200kHZ

           I2C_InitStructure.I2C_Mode                         =  I2C_Mode_I2C;

           I2C_InitStructure.I2C_DutyCycle         =  I2C_DutyCycle_2;        //根据datasheet，Tlow/Thigh = 2

           I2C_InitStructure.I2C_OwnAddress1         =  0xA0;                 

           I2C_InitStructure.I2C_Ack                          =  I2C_Ack_Enable;

           I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

        

        I2C2_Init(&I2C_InitStructure);



        for(i = 0; i < 10; i++){        

                AT24CXX_WriteByte(i, 100 + i);

                /* NOTE: 根据datasheet，两次字节写之间必须延迟5ms，也就是stop和start之间的间隔时间*/

                delay_ms(6);  

        }

        printf("Write completed \r\n");



        for(i = 0; i < 10; i++){        

                printf("%d ", AT24CXX_ReadByte(i));

            delay_ms(6);

        }

        printf("\r\n");

}