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);//持續DIN高電平寫操作，恢復AD7705接口
    HAL_Delay(1);
    commue(0x20); /* 選擇時鐘寄存器*/
    HAL_Delay(1);
    commue(0x0c); /* 配置時鐘寄存器*/
    HAL_Delay(1);
    commue(0x10); /*選擇設置寄存器*/
    HAL_Delay(1);
    commue(0x44);/*配置設置寄存器 */
}

uint16_t GetData7705_CH1(void)
{
    uint16_t DataL = 0,DataH = 0;
    HAL_Delay(1);
    commue(0x38);   //選中CH1數據寄存器讀 
   while(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1)==GPIO_PIN_SET){;}
    ////待數據準備好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電壓
}