STM32 模拟I2C （STM32F051） -
[导读]
/** ****************************************************************************** * @file i2c simu.c * @brief simulation function * @CPU STM32F051 * @compiler Keil uVision V4.74 *
/**
本文引用地址: http://www.21ic.com/app/mcu/201806/764745.htm
******************************************************************************
* @file i2c simu.c
* @brief simulation function
* @CPU STM32F051
* @compiler Keil uVision V4.74
* @author MetalSeed
* @copyright WSHHB
* @version V1.0.0
* @date 18-Sept-2014
* @modifydate20-Sept-2014
******************************************************************************
* @attention
*/
#include "boardAPI.h"
#include "i2cSimu.h"
#include "delay.h"
#include "uart.h"
GPIO_InitTypeDef GPIO_InitStructure;
/**
* @brief IIC Init
* @param A:
* @retval None
*/
void IIC_Init(void)
{
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOF, ENABLE );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT ; //í?íìê?3?
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOF, &GPIO_InitStructure);
GPIO_SetBits(GPIOF,GPIO_Pin_6|GPIO_Pin_7); //PB10,PB11 ê?3???
}
/**
* @brief Set SDA Pin as Output Mode
* @retval None
*/
void SDA_OUT()
{
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOF, &GPIO_InitStructure);
}
/**
* @brief Set SDA Pin as Input Mode
* @retval None
*/
void SDA_IN()
{
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;// !!!
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOF, &GPIO_InitStructure);
}
/**
* @brief read input voltage from SDA pin
* @retval None
*/
BYTE SDA_READ()
{
return GPIO_ReadInputDataBit(GPIOF, GPIO_Pin_7);
}
/**
* @brief output high form SDA pin
* @retval None
*/
void IIC_SDA_1()
{
GPIO_SetBits(GPIOF, GPIO_Pin_7);
}
/**
* @brief output low form SDA pin
* @retval None
*/
void IIC_SDA_0()
{
GPIO_ResetBits(GPIOF, GPIO_Pin_7);
}
/**
* @brief output high form SCL pin
* @retval None
*/
void IIC_SCL_1()
{
GPIO_SetBits(GPIOF, GPIO_Pin_6);
}
/**
* @brief output LOW form SCL pin
* @retval None
*/
void IIC_SCL_0()
{
GPIO_ResetBits(GPIOF, GPIO_Pin_6);
}
/**
* @brief Simulate IIC conmunication :Create Start signal
* @retval None
*/
void IIC_Start(void)
{
SDA_OUT(); //sda output
IIC_SDA_1();
IIC_SCL_1();
delayus(4);
IIC_SDA_0(); //START:when CLK is high,DATA change form high to low
delayus(4);
IIC_SCL_0(); //hold scl line, prepare to transmit data
}
/**
* @brief Simulate IIC conmunication : Create Stop signal
* @retval None
*/
void IIC_Stop(void)
{
SDA_OUT(); //sda output mode
IIC_SCL_0();
IIC_SDA_0(); //STOP:when CLK is high DATA change form low to high
delayus(4);
IIC_SCL_1();
IIC_SDA_1(); //indicate transmit over
delayus(4);
}
/**
* @brief Simulate IIC conmunication : wait for target device's ACK
* @retval ACK (0) : receive success
* @retval NACK(1) : receive unsuccess
*/
BYTE IIC_Wait_Ack(void)
{
BYTE ucErrTime = 0;
SDA_IN(); //set as input mode
IIC_SDA_1();
delayus(1);
IIC_SCL_1();
delayus(1);
while(SDA_READ())
{
ucErrTime++;
if(ucErrTime > 250)
{
IIC_Stop();
return 1;
}
}
IIC_SCL_0(); //release scl line
return 0;
}
/**
* @brief Simulate IIC conmunication : make an ACK
* @retval None
*/
void IIC_Ack(void)
{
IIC_SCL_0();
SDA_OUT();
IIC_SDA_0();
delayus(2);
IIC_SCL_1();
delayus(2);
IIC_SCL_0();
}
/**
* @brief Simulate IIC conmunication : don't make an ACK
* @retval None
*/
void IIC_NAck(void)
{
IIC_SCL_0();
SDA_OUT();
IIC_SDA_1();
delayus(2);
IIC_SCL_1();
delayus(2);
IIC_SCL_0();
}
/**
* @brief Simulate IIC conmunication : Transmit one byte Data
* @param txd: data to be transmit
* @retval None
*/
void IIC_Send_Byte(BYTE txd)
{
BYTE i;
SDA_OUT();
IIC_SCL_0();//push down scl to start transmit data
for(i = 0; i < 8; ++i)
{
if(txd & 0x80)
{
IIC_SDA_1();
}
else
{
IIC_SDA_0();
}
txd <<= 1;
delayus(2);
IIC_SCL_1();
delayus(2);
IIC_SCL_0();
delayus(2);
}
}
//?á1??×??ú￡?ack=1ê±￡?·￠?íACK￡?ack=0￡?·￠?ínACK
/**
* @brief Simulate IIC conmunication : Receive one byte Data
* @param ack: Whether transmit ACK
* @retval the data have been receive
*/
BYTE IIC_Read_Byte(unsigned char ack)
{
unsigned char i, res = 0;
SDA_IN(); //SDA input mode
for(i = 0; i < 8; ++i )
{
IIC_SCL_0();
delayus(2);
IIC_SCL_1();
res <<= 1;
if(SDA_READ())
{
res++;
}
delayus(1);
}
if (!ack)
{
IIC_NAck();//make NACK
}
else
{
IIC_Ack(); //make ACK
}
return res;
}
/*JUST SOME TEST FUNTION DEMO*/
BYTE ReadData()
{
BYTE temp=0;
IIC_Start();
IIC_Send_Byte(0x80);
IIC_W
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