uint8_t commue(uint8_t Dst_Addr)

{uint8_t RXdata;

  HAL_SPI_TransmitReceive(&hspi1,&Dst_Addr,&RXdata,1, 1000);

   return RXdata;

}

void Init_AD7705(void)

{

   for(int i=0;i<150;i++)commue(0xff);//持续DIN高电平写操作，恢复AD7705接口

    HAL_Delay(1);

    commue(0x20); /* 选择时钟寄存器*/

    HAL_Delay(1);

    commue(0x0c); /* 配置时钟寄存器*/

    HAL_Delay(1);

    commue(0x10); /*选择设置寄存器*/

    HAL_Delay(1);

    commue(0x44);/*配置设置寄存器 */

}

uint16_t GetData7705_CH1(void)

{

    uint16_t DataL = 0,DataH = 0;

    HAL_Delay(1);

    commue(0x38);   //选中CH1数据寄存器读

   while(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1)==GPIO_PIN_SET){;}

    ////待数据准备好AdDrdy=0

    delay_us(20);

    DataH=commue(0xff);

    DataL=commue(0xff);

    delay_us(100);

    DataH = DataH << 8;

    return (DataH | DataL);

}

float ADC_7705(void)

{

        Init_AD7705();

        float RCH1_16bit=GetData7705_CH1();

        return (RCH1_16bit*5049.0/65535); //算出通道1电压

}