159 lines
3.1 KiB
C
159 lines
3.1 KiB
C
/*
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* iic.c
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*
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* Created on: Oct 24, 2021
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* Author: wuwenfeng
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*/
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#include "iic.h"
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#include "gpio.h"
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#define iic_sda(x) HAL_GPIO_WritePin(iic_sda_GPIO_Port, iic_sda_Pin, x)
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#define iic_scl(x) HAL_GPIO_WritePin(iic_scl_GPIO_Port, iic_scl_Pin, x)
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#define read_iic_sda HAL_GPIO_ReadPin(iic_sda_GPIO_Port, iic_sda_Pin)
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#define IIC_SDA_SET iic_sda(1)
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#define IIC_SCL_SET iic_scl(1)
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#define IIC_SDA_CLR iic_sda(0)
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#define IIC_SCL_CLR iic_scl(0)
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#define SDA_OUT() change_io_function(iic_sda_GPIO_Port, iic_sda_Pin,0)
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#define SDA_IN() change_io_function(iic_sda_GPIO_Port, iic_sda_Pin,1)
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#define READ_SDA read_iic_sda
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//产生IIC起始信号
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void IIC_Start(void)
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{
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SDA_OUT(); //sda线输出
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IIC_SDA_SET;
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IIC_SCL_SET;
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IIC_SDA_CLR;//START:when CLK is high,DATA change form high to low
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IIC_SCL_CLR;//钳住I2C总线，准备发送或接收数据
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}
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//产生IIC停止信号
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void IIC_Stop(void)
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{
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SDA_OUT();//sda线输出
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IIC_SCL_CLR;
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IIC_SDA_CLR;//STOP:when CLK is high DATA change form low to high
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IIC_SCL_SET;
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IIC_SDA_SET;//发送I2C总线结束信号
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}
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//等待应答信号到来
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//返回值：1，接收应答失败
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// 0，接收应答成功
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uint8_t IIC_Wait_Ack(void)
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{
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uint8_t ucErrTime=0;
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SDA_IN(); //SDA设置为输入
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IIC_SDA_SET;
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IIC_SCL_SET;
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while(READ_SDA)
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{
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ucErrTime++;
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if(ucErrTime>250)
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{
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IIC_Stop();
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return 1;
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}
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}
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IIC_SCL_CLR;//时钟输出0
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return 0;
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}
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//产生ACK应答
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void IIC_Ack(void)
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{
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IIC_SCL_CLR;
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SDA_OUT();
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IIC_SDA_CLR;
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IIC_SCL_SET;
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IIC_SCL_CLR;
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}
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//不产生ACK应答
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void IIC_NAck(void)
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{
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IIC_SCL_CLR;
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SDA_OUT();
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IIC_SDA_SET;
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IIC_SCL_SET;
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IIC_SCL_CLR;
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}
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//IIC发送一个字节
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//返回从机有无应答
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//1，有应答
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//0，无应答
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void IIC_Send_Byte(uint8_t txd)
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{
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uint8_t t;
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SDA_OUT();
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IIC_SCL_CLR;//拉低时钟开始数据传输
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for(t=0;t<8;t++)
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{
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//IIC_SDA=(txd&0x80)>>7;
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if((txd&0x80)>>7)
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IIC_SDA_SET;
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else
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IIC_SDA_CLR;
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txd<<=1;
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IIC_SCL_SET;
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IIC_SCL_CLR;
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}
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}
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//读1个字节，ack=1时，发送ACK，ack=0，发送nACK
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uint8_t IIC_Read_Byte(unsigned char ack)
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{
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unsigned char i,receive=0;
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SDA_IN();//SDA设置为输入
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for(i=0;i<8;i++ )
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{
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IIC_SCL_CLR;
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IIC_SCL_SET;
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receive<<=1;
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if(READ_SDA)receive++;
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}
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if (!ack)
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IIC_NAck();//发送nACK
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else
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IIC_Ack(); //发送ACK
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return receive;
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}
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void IIC_SAND_DATE(unsigned char DEVICE_ADD,unsigned char IN_DEVICE_ADD,char *DATAS,uint16_t LONG)
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{
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IIC_Start();
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IIC_Send_Byte(DEVICE_ADD);
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if(IIC_Wait_Ack()){return;}
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IIC_Send_Byte(IN_DEVICE_ADD);
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if(IIC_Wait_Ack()){return;}
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for(int a=0;a<LONG;a++)
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{
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IIC_Send_Byte(*DATAS);
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DATAS++;
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}
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if(IIC_Wait_Ack()){return;}
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IIC_Stop();
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}
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void IIC_READ_DATE(unsigned char DEVICE_ADD,unsigned char IN_DEVICE_ADD,char *DATAS,uint16_t LONG)
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{
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IIC_Start();
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IIC_Send_Byte(DEVICE_ADD);
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if(IIC_Wait_Ack()){return;}
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IIC_Send_Byte(IN_DEVICE_ADD);
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if(IIC_Wait_Ack()){return;}
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IIC_Start();
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IIC_Send_Byte(DEVICE_ADD+1);
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if(IIC_Wait_Ack()){return;}
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for(int a=0;a<LONG;a++)
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{
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*DATAS=IIC_Read_Byte(0);
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DATAS++;
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}
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if(IIC_Wait_Ack()){return;}
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IIC_Stop();
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}
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