AT24C02接收到的数据总是255-HerryZ的回答

AT24C02接收到的数据总是255

2019-07-20 13:27发布

原子大神求救啊。我在EEPROM中地址为0的地方写进数字16，可是读出来却是255.这说明EEPROM在传数据的时候根本没有拉低电平，这是怎么回事啊？下面附有我的程序#include "IIC.h"//*******************************IIC总线*********************************//
#include "systick.h"
void IIC_init()
{
      GPIO_InitTypeDef GPIO_InitStructure;
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
      GPIO_InitStructure.GPIO_Pin = IIC_SCL|IIC_SDA;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
      GPIO_Init(GPIOB,&GPIO_InitStructure);

      IIC_SCL_H;
      IIC_SDA_H;
}

void IIC_SDA_OUT()
{
      GPIO_InitTypeDef GPIO_InitStructure;
      GPIO_InitStructure.GPIO_Pin = IIC_SDA;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
      GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void IIC_SDA_IN()
{
      GPIO_InitTypeDef GPIO_InitStructure;
      GPIO_InitStructure.GPIO_Pin = IIC_SDA;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
      GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void IIC_Start()
{
      IIC_SDA_OUT();
      IIC_SDA_H;
      IIC_SCL_H;
      delay_us(5);
      IIC_SDA_L;
      delay_us(6);
      IIC_SCL_L;
}

void IIC_Stop()
{
      IIC_SDA_OUT();
      IIC_SCL_L;
      IIC_SDA_L;
      IIC_SCL_H;
      delay_us(6);
      IIC_SDA_H;
      delay_us(6);

}

void IIC_Ack()                //主机应答
{
      IIC_SCL_L;
      IIC_SDA_OUT();
      IIC_SDA_L;
      delay_us(2);
      IIC_SCL_H;
      delay_us(5);
      IIC_SCL_L;

}

void IIC_NAck()                //主机非应答
{
      IIC_SCL_L;
      IIC_SDA_OUT();
      IIC_SDA_H;
      delay_us(2);
      IIC_SCL_H;
      delay_us(5);
      IIC_SCL_L;
}

u8 IIC_Wait_Ack()                //主机等待从机应答       失败：1 成功：0
{
      u8 temptime=0;
      IIC_SDA_IN();
      IIC_SDA_H;
      delay_us(1);
      IIC_SCL_H;
      delay_us(1);

      while(GPIO_ReadInputDataBit(GPIO_IIC, IIC_SDA))
      {
            temptime++;
            if(temptime>250)
            {
                     IIC_Stop();
                     return 1;
            }
      }
      IIC_SCL_L;
      return 0;
}

void IIC_Send_Byte(u8 txd)
{
      u8 i=0;
      IIC_SDA_OUT();
      IIC_SCL_L;
      for(i=0;i<8;i++)
      {
            if(txd&0X80>0)
                     IIC_SDA_H;
            else
                     IIC_SDA_L;
            txd<<=1;
            IIC_SCL_H;
            delay_us(2);
            IIC_SCL_L;
            delay_us(2);

      }
}

u8 IIC_Read_Byte(u8 Ack)
{
      u8 i=0;
      u8 receive=0;
      IIC_SDA_IN();
      for(i=0;i<8;i++)
      {
               IIC_SCL_L;
            delay_us(2);
               IIC_SCL_H;
            receive<<=1;
            if(GPIO_ReadInputDataBit(GPIO_IIC, IIC_SDA))
                     receive++;
            delay_us(1);
      }

      if(Ack==0)
            IIC_NAck();
      else
            IIC_Ack();
      return receive;
}
//******************************AT24C02写入读出**********************//
#include "AT24Cxx.h"

u8 AT24Cxx_ReadOneByte(u16 addr)
{
      u8 temp=0;
      IIC_Start();
      if(EE_TYPE>AT24C16)
      {
            IIC_Send_Byte(0xA0);
            IIC_Wait_Ack();
            IIC_Send_Byte(addr>>8);

      }
      else
      {
            IIC_Send_Byte(0xA0+((addr/256)<<1));

      }
      IIC_Wait_Ack();
      IIC_Send_Byte(addr%256);
      IIC_Wait_Ack();

      IIC_Start();
      IIC_Send_Byte(0xA1);
      IIC_Wait_Ack();
      temp=IIC_Read_Byte(0);
      IIC_NAck();
      IIC_Stop();

      return temp;

}

u8 AT24Cxx_ReadTwoByte(u16 addr)
{
      u16 temp=0;
      IIC_Start();
      if(EE_TYPE>AT24C16)
      {
            IIC_Send_Byte(0xA0);
            IIC_Wait_Ack();
            IIC_Send_Byte(addr>>8);

      }
      else
      {
            IIC_Send_Byte(0xA0+((addr/256)<<1));

      }
      IIC_Wait_Ack();
      IIC_Send_Byte(addr%256);
      IIC_Wait_Ack();

      IIC_Start();
      IIC_Send_Byte(0xA1);
      IIC_Wait_Ack();
      temp=IIC_Read_Byte(1);
      temp<<=8;
      temp|=IIC_Read_Byte(0);
      IIC_Stop();
      return temp;
}

void AT24Cxx_WriteOneByte(u16 addr,u8 dt)
{
      IIC_Start();
      if(EE_TYPE>AT24C16)
      {
            IIC_Send_Byte(0xA0);
            IIC_Wait_Ack();
            IIC_Send_Byte(addr>>8);

      }
      else
      {
            IIC_Send_Byte(0xA0+((addr/256)<<1));

      }
      IIC_Wait_Ack();
      IIC_Send_Byte(addr%256);
      IIC_Wait_Ack();
      IIC_Send_Byte(dt);
      IIC_Wait_Ack();
      IIC_Stop();
      delay_ms(10);
}

void AT24Cxx_WriteTwoByte(u16 addr,u16 dt)
{
      IIC_Start();
      if(EE_TYPE>AT24C16)
      {
            IIC_Send_Byte(0xA0);
            IIC_Wait_Ack();
            IIC_Send_Byte(addr>>8);

      }
      else
      {
            IIC_Send_Byte(0xA0+((addr/256)<<1));

      }
      IIC_Wait_Ack();
      IIC_Send_Byte(addr%256);
      IIC_Wait_Ack();
      IIC_Send_Byte(dt>>8);
      IIC_Wait_Ack();
      IIC_Send_Byte(dt&0x0ff);
      IIC_Wait_Ack();
      IIC_Stop();
      delay_ms(10);
}

//****************************printf****************************//
#include "printf.h"
int fputc(int ch,FILE *p)
      {
      USART_SendData(USART1,(u8)ch);
      while(USART_GetFlagStatus(USART1, USART_FLAG_TXE)==RESET);
      return ch;
      }

void printf_init()
      {       GPIO_InitTypeDef GPIO_InitStructure;
               USART_InitTypeDef USART_InitStructure;
            NVIC_InitTypeDef NVIC_InitStructure;

            SystemInit();
            RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
            RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
            RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);

            GPIO_InitStructure.GPIO_Pin=GPIO_Pin_9;                                     //tx
            GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
            GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP ;
            GPIO_Init(GPIOA,&GPIO_InitStructure);

            GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10;                               //rx
            GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING  ;
            GPIO_Init(GPIOA,&GPIO_InitStructure);

            USART_InitStructure.USART_BaudRate = 9600;
            USART_InitStructure.USART_WordLength = USART_WordLength_8b;
            USART_InitStructure.USART_StopBits = USART_StopBits_1;
            USART_InitStructure.USART_Parity = USART_Parity_No;
            USART_InitStructure.USART_HardwareFlowControl =USART_HardwareFlowControl_None ;
            USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
            USART_Init(USART1, &USART_InitStructure);

            USART_Cmd(USART1, ENABLE);
            USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
            USART_ClearFlag(USART1,USART_FLAG_TC);

            NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
            NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
            NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =0;
            NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;
            NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
            NVIC_Init(&NVIC_InitStructure)       ;
}

//******************************main**************************//
#include "systick.h"
#include "public.h"
#include "printf.h"
#include "AT24Cxx.h"

int main()
{
      u8 wdate=16;
      u8 value=0;
      printf_init();
      IIC_init();
      delay_ms(1);

      AT24Cxx_WriteOneByte(0,wdate);
      printf("写入的是:%d ",wdate);
      value=AT24Cxx_ReadOneByte(0);
      printf("读出的是:%d ",value);
      while(1);
}

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8条回答

HerryZ

2019-07-21 09:58

4楼说的对，检查程序问题。我曾经也遇到过。你直接复制原子哥的程序试试

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