STM32--模拟I2C

1、STM32-模拟 I2C_2402-SDA_H,SDA_L标签：cdelayconstantsvariablesapplicationfile2011-01-02 10:10 5564 人阅读 评论(0)收藏 举报HE分类：STM32 (9)已I2C的引脚配置：/* Configure I2C1 pins: SCL and SDA */GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 |GPIO_Pin_7;/? QUS1:STM32 内部结构GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_InitSt

2、ructure.GPIO_Mode = GPIO_Mode_Out_OD; /? QUS2:种模 式的区别GPIO_Init(GPIOB, &GPIO_InitStructure);/* File Name : i2c_fram.h* Author: MCD Application Team* Version: V2.0.1* Date: 06/13/2008* Description : Header for i2c_ee.c module*/*/* Define to prevent recursive inclusion*/#ifndef _I2C_FRAM_H#define _I2C_

3、FRAM_H/* Includes*/#include stm32f10x_lib.h/* Exported types*/* Exported constants*/* Exported macro*/* Exported functions*/ /*主函数的调用格式，重点。1主机存放数据的地址，2.2402写入地址，3.写入个如：#define pr(u8*)0x2000f32c)(pr,0,1) */bool I2C_FRAM_BufferWrite(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite);bool I2C_FRAM_BufferR

4、ead(u8* pBuffer, u16 ReadAddr, u16 NumByteToRead);* endif /* _I2C_FRAM_H */* File Name : i2c_fram.c* Author: Appcat* Version: V0.0.1* Date: 07/11/2009* Description : This file provides a set of functions needed to manage the*communication between I2C peripheral and I2C FM24CL16FRAM.*/*/* Includes*/#

5、include i2c_fram.h/* Private typedef*/* Private define*/#define I2C_Speed100000#define I2C1_SLAVE_ADDRESS7 0xA0#define I2C_PageSize256 /一页的大小，此处设置一个芯片为一页#define SCL_H GPIOB-BSRR = GPIO_Pin_6 /STM32 的两个很 specil 的 寄存器，可很方便的实现 GPIO的置1/置0的动作。#define SCL_L GPIOB-BRR = GPIO_Pin_6 / QUS3:进一步了解这两个寄存器，区别于ODR

6、/IDR，初始化#define SDA_H#define SDA_L#define SCL_read#define SDA_readGPIOB-BSRR = GPIO_Pin_7GPIOB-BRR = GPIO_Pin_7GPIOB-IDR & GPIO_Pin_6GPIOB-IDR & GPIO_Pin_7/* Private macro*/* Private variables*/ vu8 FRAM_ADDRESS;*/* Private function prototypesvoid I2C_delay(void)u8 i=150; /这里可以优化速度，经测试最低到5还能写入whilei

7、-；bool I2C_Start(void) / QUS4:STM32 中的 bool 类型是不是和 51 中的 sbit 是一个类 型SDA_H;SCL_H;I2C_delay();if(!SDA_read)return FALSE; /SDA线为低电平则总线忙，退出SDA_L;I2C_delay();if(SDA_read) return FALSE; /SDA线为高电平则总线出错，退出SDA_L;I2C_delay();return TRUE;void I2C_Stop(void)SCL_L;I2C_delay();SDA_L;I2C_delay();SCL_H;I2C_delay();

8、SDA_H;I2C_delay();void I2C_Ack(void)SCL_L;I2C_delay();SDA_L;I2C_delay();SCL_H;I2C_delay();SCL_L;I2C_delay();void I2C_NoAck(void)SCL_L;I2C_delay();SDA_H;I2C_delay();SCL_H;I2C_delay();SCL_L;I2C_delay();bool I2C_WaitAck(void)返回为：=1 有 ACK,=0 无 ACKSCL_L;I2C_delay();SDA_H;I2C_delay();SCL_H;I2C_delay();if(

9、SDA_read)SCL_L;return FALSE;SCL_L;return TRUE;void I2C_SendByte(u8 SendByte)/数据从高位到低位 /u8 i=8;while(i-)SCL_L;I2C_delay();if(SendByte&0x80)SDA_H;elseSDA_L;SendByte=1;I2C_delay();SCL_H;I2C_delay();SCL_L;u8 I2C_ReceiveByte(void)/数据从高位到低位 /u8 i=8;u8 ReceiveByte=0;SDA_H;while(i-)ReceiveByte=1;SCL_L;I2C_d

10、elay();SCL_H;I2C_delay();if(SDA_read)ReceiveByte|=0x01;SCL_L;return ReceiveByte;bool I2C_FRAM_BufferWrite(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite)u8 Addr = 0, count = 0;Addr = WriteAddr / I2C_PageSize; /I2C_PageSize 可在宏定义中更改页面大小。 count = WriteAddr % I2C_PageSize;/ 用除余将其分页，理解 。Addr = Addr 1;Ad

11、dr = Addr & 0x0F;FRAM_ADDRESS = I2C1_SLAVE_ADDRESS7 | Addr;if (!I2C_Start() return FALSE;I2C_SendByte(FRAM_ADDRESS);/ 设置器件地址+段地址/1.第一次发送字节，被认为是器件地址(A0A1A2),以及段地址(页/片地址)if (!I2C_WaitAck() I2C_Stop();return FALSE;I2C_SendByte(count); /设置段内地址 /2第二次发送字节，被认为是被选中 的片的内部地址I2C_WaitAck();while(NumByteToWrite-

12、) I2C_SendByte(* pBuffer); /3第三次发送就可以是写入/读取的内容的。I2C_WaitAck();pBuffer+;I2C_Stop();注意：因为这里要等待 EEPROM写完，可以采用查询或延时方式(10ms) /Systick_Delay_1ms(10);return TRUE;/读出1串数据bool I2C_FRAM_BufferRead(u8* pBuffer, u16 WriteAddr, u16 NumByteToRead) u8 Addr = 0, count = 0;Addr = WriteAddr / I2C_PageSize;count = WriteAddr % I2C_PageSize;Addr = Addr 1;Addr = Addr & 0x0F;FRAM_ADDRESS = I2C1_SLAVE_ADDRESS7 | Addr;if (!I2C_Start() return FALSE;I2C_SendByte(FRAM_ADDRESS);/ 设置器件地址 + 段地址if (!I2C_WaitAck()I2C_Stop();return FALSE;I2C_SendByte(count);/设置低起始地址I2C_WaitAck();I2