AD74412RBCPZ unable to communicate with arduino(SPI)

I have being trying to communicate with AD74412 with SPI using arduino and STM32h723 development board no matter how hard I tried I am unable to receive any data from that AD74412 IC.

Datasheet says first we have to clear Alert status register bits and i did and in order to read something i have to use Readback select register and I am doing everything according to the datasheet I am not receiving any data at the output. And this sensor i cannot simply send dummy clocks and get the data it requires me to write the address of the register which i want to read inn Readselect register.

Is there something else I am missing here the PC based software seems to work fine but when i use arduino noting happens.

Kindly help me I am working some important project and also if there any library files available please so share me. I will be off loaded.

  • 0
    •  Analog Employees 
    on Jun 24, 2021 7:58 AM

    Hi Ankit,

    Can you please check if the Reset pin is pulled high in your setup? The GUI takes care of this as there is no pullup on the evaluation board. 

    Thanks,

    Bríde

  • you are right the reset was one of the issue after doing everything i found reset is not pulled high after  fixing that problem by pulling it up with 3K resistor I tries running the same program again but still it didn't work. and the Alert_pin is always low. and before fixing the reset issue it was always high. That makes things too hard i have no idea what's going i expect the alert pin to get low only when I make a CRC error. or some error while sending data but instead its always low.

  • The GUI takes care of this as there is no pullup on the evaluation board. 

    yesterday only I noticed this, I think this counts as a bug in AD's product simply there could have added a pull up instead of making the user to figure this out.

  • +1
    •  Analog Employees 
    on Jun 24, 2021 10:15 AM in reply to Ankit-anklabs

    Hi Ankit, 

    This is as expected. The Alert pin will assert low on power up as the part comes out of the Power on Reset cycle. 

    If you were able to read the Alert status register, you would see the "Reset Occurred" bit asserted. 

    Let's first confirm that the device is powered up fully. Can you confirm the following voltages (which can be measured using the test points on the board)

    1.  AVDD, AVSS, 
    2.  DVCC & IOVDD, 
    3.  REFIN
    4.  ALDO5V, DLDO1V8, ALDO1V8

    Can you also send a scope-shot of your SPI sequence? 

    I suggest a read from the ALERT_STATUS register:

    1. 1st frame: write 0x2E (address of ALERT_STATUS register) to READ_SELECT register (0x41)
    2. 2nd frame: a NOP command (0x0 data to 0x0 register) can be applied. the ALERT_STATUS data should be available on the SDO pin. 

    It would be good to confirm the SPI signals on the AD74413R board if possible. R13 - R16 are all on the SPI lines. 

    Thanks,

    Bríde

  • Thanks I will do as you say well i already did but this time I will make LDAC pin pull down and make sure ALERT and ADC_RDY pin are pulled up I am doing everything right but I am missing things somewhere.

    I will check all test points and is it normal to have -1.7 volt at charge pump pin the datasheet says trip level at -1.65 volt.

    ok I am going to test the board.....