why can't make recording output after increasing frame rate

Discussion in 'Presence Sensor' started by Yang Han, May 30, 2018.

  1. Yang Han

    Yang Han New Member

    Hi!
    I'm tring to increase higer frame rate to 500 samples/s. I have tried the xep_fps_test.py and it works well. But when I make the same configures as in the xep_fps_test.py and try to make recording, no recording file show up after the fps is set above 40. My matlab for recording is attached, could you please help me find where is the problem? The current fps is set to 40 and it will fail to provide recording file when fps is set above 40.
     

    Attached Files:

  2. Charlie Shao

    Charlie Shao Moderator Staff Member

    HI Yang,

    Sorry, I did not have time to check your Matlab script, but I did a quick test with the following python script. It proves that Module Connector Recorder can work well with your setting on high FPS:
    It uses the same configuration as yours:
    xep.x4driver_set_dac_min(900)
    xep.x4driver_set_dac_max(1150)
    xep.x4driver_set_iterations(4)
    xep.x4driver_set_pulses_per_step(10)
    xep.x4driver_set_downconversion(int(baseband))

    I choose FPS = 1400, which make X4 duty cycle 94.01547325%.
    Run command "python XEP_plot_record_playback.py -d com13 -b -r" with your own serial port name, it can successfully record the data.
     

    Attached Files:

  3. Yang Han

    Yang Han New Member

    I’ll have a try, thanks a lot!
     
  4. Yang Han

    Yang Han New Member

    Hi Charlie:

    I tried the XEP_x4_configuration again in matlab with recording type set to be float data type instead of Ap or Iq and it works now. I'm writing this just to make sure my understanding is right:recording through XEP can only provide baseband generic float data, and the IQ baseband data can be obtained via iqVec=data(1:length/2)+1i*data(length/2+1:end), is this right?

    Another question is that when doing recording though XEP, the light of X4M300 keeps to be blue, but when doing recording through other scripts, the light will flash with yellow and green, so I wonder whether the sensor is working when the light keeps to be blue.
     
  5. Charlie Shao

    Charlie Shao Moderator Staff Member

    Hi Yang,
    X4M300 can operate at two level: X4Driver level and Application level.
    The FPS is fixed to 17 at Application level. You are able to change FPS at X4Driver level, but it only supports float data output. Here the float data is raw baseband IQ data. Using baseband IQ data, you can easily calculate AP data, please refer to XeThru File Formats section 2.1. X4M300 has presence profile running on Application level, its LED is set to FULL mode by default. According to X4M300 datasheet section 4.2.3, when X4M300 run at X4Driver, no profile running, it will repeat: Blue (0.2 sec) -> Off (4.7 sec), so there is no problem with the blue led.

    XeThru MCP Document: https://www.xethru.com/community/resources/xethru-module-communication-protocol.130/
    XeThru File Formats Document: https://www.xethru.com/community/resources/xethru-file-formats.55/
    X4M300 datasheet: https://www.xethru.com/community/resources/x4m300-presence-sensor-datasheet.83/
     
  6. Yang Han

    Yang Han New Member

    Thank you very much for your help, Charlie! I’m clear about it now.