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RTOS/AFE5816: How to let the AFE work without the use of TSW1400? Could it be done by writing SPI to AFE? How could the SPI be written into the AFE?

Part Number: AFE5816

Tool/software: TI-RTOS

To someone who may concern,

Hi, I am a PhD candidate in Nanyang Technological University, Singapore. Now we are trying to construct a portable medical system concluding sensors, AFE, wireless module and FPGA, applying to ultrasound healthcare. We use AFE5816 as the analog front end, however, we don't want to use the TSW1400 because it needs to connect to computer and use the GUI. which is not suitable for portable devices. We try to let the AFE5816 work without TSW1400 by applying the SPI signals(SCLK, SEN,SDATA) to the AFE5816 through Arduino. We have removed the R22 near U9 at the bottom of the board as the manual indicates, however, the SPI still could not be written into the AFE5816. Could I ask how to write SPI to AFE5816 or do you have any other suggestions to let the AFE5816 work without the use of TSW1400? Thank you very much!

Best regards,

Fang Zhongyuan, Phd Candidate, NTU, Singapore

  • Hi Fang,

    Can you provide an oscilloscope capture of the SPI lines from the Arduino?

    Sincerely,
    Olu
  • In reply to Olu Sodipe:

    OK. It's the 3.3v peak value, 10K Hz, square wave signal for the SCLK, and the corresponding SEN according to the AFE5816 manual indicates and SDATA to write the register address, which is 00000001 and corresponding register value, which is 0000000000010100. According to the oscilloscope capture, the SPI signal generated by Arduino is right in voltage value and waveform. However, the generated SPI seems cannot be written into the AFE5816. I want to know if the AFE5816 can work without the use of TSW1400. If it can, how to make it work, except setting SDATA, SCLK, SEN, what other ports need to be set? I notice there exists a DIG_SPI port on AFE5816, but the manual doesn't smention how to set its waveform, maybe it need to be set? Thank you very much.
  • In reply to ZhongYuan Fang:

    Hi Fang,

    The SPI_DIG pin is not needed for SPI communication with the AFE5816. Did you connect the GND pins together?
    You can also try bringing up the AFE5816 using the TSW1400 first then disconnecting R22 while the board is still configured.
    After this, you can try simple register writes like changing ADC patterns from ramp to analog signal, etc.

    It would also really help if you could post oscilloscope captures of your SPI write signals.

    Sincerely,
    Olu
  • In reply to Olu Sodipe:

    Hi, Dear Mr. Sodipe,

    Thank you very much for your kind response. Could I have your e-mail address so that I can send you the oscilloscope captures of the SPI signals we generated? Thank you very much.

    Best regards,

    Fang Zhongyuan, Phd Student, NTU, Singapore
  • In reply to Olu Sodipe:

    Could you please tell me how to "bring up the AFE5816 using the TSW1400 first then disconnecting R22 while the board is still configured"? Do you mean remove the R22 while the AFE5816 and TSW1400 are connected to PC through USB while both power is on ? We removed the R22 of the AFE5816 under the circumstance the power of AFE5816 is off.
  • In reply to ZhongYuan Fang:

    Hi Fang,

    You can solder two wires to R22's pads and have a grabber-to-grabber cable connecting both wires together. Once the AFE5816EVM is configured via the HMC-DAQ and is able to complete data captures, you can then disconnect the grabber-to-grabber and use the Arduino for SPI communications instead.

    Sincerely,

    Olu

  • In reply to Olu Sodipe:

    Hi Fang,

    How did it go when you used the GUI to initialize the AFE5816EVM as I recommended?
    If you are still having trouble, before you write to a given register, write 0x0000 to register 0x00 in order to make sure that the device is in write mode first.
    Another thing to check is the SPI clock phase and polarity for your Arduino.

    Once you have the AFE5816EVM initialized using the GUI, you can try changing pattern modes via SPI using register 0x02.
    Then we can go to the next step of initializing the AFE5816 without the GUI.

    Sincerely,
    Olu
  • In reply to Olu Sodipe:

    Hello,

    I am contacting from Chonbuk National University, Korea. We have been developing and implementing a new ultrasound prototype system based on AFE5816EVM and FPGA. I am trying to implement 4 AFE5816EVMs and Xilinx Kintex-7 EVM. But there is no more information about AFE5816EVM such as board real dimensions, so I have a problem to draw a new PCB which is connect between 4 AFE5816EVM and Kintex-7 EVM. Is there any information about dimension of AFE5816EVM? Please share to me.
    Thank you