• AD7790读取数据问题

    AD7790采用默认设置,未修改,直接读取数据代码如下:

    WORD readAd7790_S()
    {
          BYTE temp;
          WORD result;
          temp=0x80;

         while(temp&0x80==0x80)
         {
              delay_ms(10);
              temp=SendandRecvSPI_8(WRITECOM_CMD);//写通讯寄存器 WRITECOM_CMD=0x00
              temp=SendandRecvSPI_8(READSTATUS_CMD);/…

  • AD7790数据读取异常

    AD7790上电默认连续转换模式,初始化配置为100Hz速率,利用SPI_RDY作为STM32的外部中断,读取ADC转换结果,相关代码如下:

    // ADC初始化,配置100Hz更新速率

    void AD_Init()
    {

    SPI1_Init();

    SPI_CS1=0;
    SPI1_ReadWriteByte(0x20); 
    SPI1_ReadWriteByte(0x01);

    }

    // ADC 数据读取

    u16 ad_read()
    {

    u16 RXbuf;
    //SPI_CS1=0;
    EE_CS = 1;
    SPI1_ReadWriteByte…

  • AD7790数据读取异常

    AD7790上电默认连续转换模式,初始化配置为100Hz速率,利用SPI_RDY作为STM32的外部中断,读取ADC转换结果,相关代码如下:

    // ADC初始化,配置100Hz更新速率

    void AD_Init()
    {

    SPI1_Init();

    SPI_CS1=0;
    SPI1_ReadWriteByte(0x20); 
    SPI1_ReadWriteByte(0x01);

    }

    // ADC 数据读取

    u16 ad_read()
    {

    u16 RXbuf;
    //SPI_CS1=0;
    EE_CS = 1;

  • AD7790数据转换时间的问题

    AD7790数据手册15页中单次转换模式中描述  ”AD7790上电,执行单次转换,然后返回关断模式。转换需要的时间长度为2*tADC。”这里更新速率采用16.6Hz,正常工作模式不分频单次转换的时间是多少?  单次转换的电压是哪个时刻的电压,时启动时采集到的电压,还是转换过程中电压的均值,还是其他?  这部分不太了解  希望能帮忙讲清转换的时间与采集电压信号位置的问题。   另外连续模式、连续读取模式  转换时间与电压信号采集位置是否与单次模式相同? 若不相同请说明一下,谢谢。

  • RE: CN0396_example project

    Hi Dusans,

    The only current demo example of the CN0396 is using the ADICUP360, with the Alphasense sensor provided.

    For Raspberry Pi, Analog Devices has its own Linux distribution (called Kuiper Linux) we provide that include lots of Linux device drivers…

  • RE: Common mode vlotage of AD7792 AIN input

    Another issue is:

    This is the requirment of AD7790 Analog Inputs.

    AD7790 also have in-AMP, but looks this chip have no requirment for Common-mode voltage

    Could you introduce more details about the reason.

    You introduction will let me understand this…

  • CMRR and PSRR parameter interpretation

    Our application is sensitive to offset voltage to keep leakage current
    measurement dynamics as high as possible. AD7788 specifies typ.<3uV offset
    but not input voltage, at which is measured. Could you specify it? If input
    offset is say…

  • AD7790_SPI尖峰

    Hollysys有一个关于AD7790的问题(ADR361用作基准电压源),这家公司是中国的一家大DCS客户。他们使用数据手册第15页所述的连续转换模式。他们发现,当SCLK引脚上有干扰时(例如用手触摸),AD7790就会进入一种Dout/Ready引脚始终处于高电平状态的模式。我不知道AD7790为什么会进入这种模式。如果一个周期中发生错误,下一个周期将正常,RDY将再次处于低电平,因为它是处于连续转换模式。客户没有MCU的仿真条件,难以回读AD7790的寄存器位。

    您有什么主意吗?感谢您的一贯帮助…

  • RE: CN-0357 Design Details

    Hi Willm_van. Sorry for the late reply! Here are a couple of my notes on this circuit:

    1. U2-A is used in a potentiostat configuration. Electrochemical gas sensors usually have a bias requirement wherin the voltage difference between RE and WE must a certain…
  • RE: AD7779 pH, EC and temperature

    We have a two EC designs that use discrete ADC's and might be able to get you jump started on your work. CN0357 uses the AD7790 and the CN0396 uses the AD7798.  Both designs have hardware and software available that you can use to quickly prototype…