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attila

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Posts posted by attila

    I think it's broken

    in Test and Measurement

    Posted

    Hi @Camarillo

    I meant measuring the VOFF_SC2 relative to the device GND with external DMM.
    Having the scope channel 2 range 500mV/div or lower, changing the offset between -2.5V and 2.5V should change the VOFF_SC2 between ~1V and ~3V
    Above 500mV/div for offset between -25V and +25V change VOFF between ~1V and ~3V.

    I think it's broken

    in Test and Measurement

    Posted

    Hi @Camarillo

    Probably some high voltage transient input or accidentally having the probe at 1x with high voltage damaged the ADG612.

    Before replacing the ADG612 you could verify the VREF_SC2 and VOFF_SC2 voltages.
    https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual#scope_reference_and_offset
    - the VREF should be about 2V
    - the VOFF with:
       0V offset about 2V
       +2.5V offset with 500mV/div range about 3V, like the screenshot below
       --2.5V offset with 500mV/div range about 1V

    image.png.a00584b5160cef32772b63eb85250b7c.pngimage.thumb.png.c933264f586dbf022bc47d05ea4ad2ee.png

    image.png.3de50a2b06179d2025c158b39c774c97.png

    Some further troubleshooting posts:

     

    Waveforms with accelerometer

    in Test and Measurement

    Posted

    Hi @sib

    Here you have script for ACL2. 

    // Pmod ACL2 - ADXL362

Select.Active.value = 0;
Clock.Polarity.value = 0;
Clock.Phase.value = 0;
if(Clock.Frequency.value > 1e6) Clock.Frequency.value = 1e6;

Start();
Write(8, 0x0B, 0x00);  // Read Register, Device ID
var rgID = Read(8, 4);
Stop();
if(rgID[0] != 0xAD || rgID[1] != 0x1D || rgID[2] != 0xF2){
    return "Device ID mismatch "+rgID;
}

Start();
Write(8, 0x0A, 0x2D, 0x02);     // Power Control Register, Measurement Mode
Stop();


Start();
Write(8, 0x0B, 0x0E);     // Read Register, Data
var rg = Read(8, 8);
Stop();

// convert data bits to signed value relative to gravitational constant
// MSbit sign, LSBit 0.001g for default 2g mode
var gx = (0.001* ((rg[1]<<28) | (rg[0]<<20)) /1048576).toFixed(3);
var gy = (0.001* ((rg[3]<<28) | (rg[2]<<20)) /1048576).toFixed(3);
var gz = (0.001* ((rg[5]<<28) | (rg[4]<<20)) /1048576).toFixed(3);
var tp = (0.065* ((rg[7]<<28) | (rg[6]<<20)) /1048576).toFixed(2);

return "X: "+gx+"g  Y: "+gy+"g  Z: "+gz+"g  Temp: "+tp+"*C";

     

    The measurements seem to be less accurate, see the ADXL362 datasheet regarding specs and calibration...

    image.thumb.png.782a770db4be1551dbad5c0e7c027556.png

    Analog Discovery 2 losing connection.

    in Test and Measurement

    Posted

    Hi @dave slagle

    The USB connector in the AD2 is strong and reliable. I'm using some since many years and never had any problem with it. Except some cables are not making good contact with one device or the other kind of devices.
    On your device some USB cable or try to reversely plug could have damaged the socket.

    I don't think the two year old device is in warranty... You should try to replace the USB connector.

    Waveforms with accelerometer

    in Test and Measurement

    Posted

    Hi @sib

    Thank you for the photo and screenshot. The wiring looks good.
    At the moment I can't find ACL2, only ~20 other PMods, but the last time I've checked it was working.

    You have selected the example for ACL with ADXL345. This has different command set than the ACL2 with ADXL362 IC. Probably you wanted to say ACL2 and not ACL5.

    Under the Custom tab select the ACL3/2 with ADXL362 and Run. These is a typo mistake, it should be ACL2 instead ACL3.
    In case you use the Logic Analyzer, the Protocol tool won't be able to read data, so the uncheck this option otherwise you will get "Device ID mismatch".

    image.png.3f4152b1d7ed5a0d7d6236bb4bf43c72.png

     

    You can also use the Master tab

    image.png.91aef23292f2d7acaf3533495f9737e5.png

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