Andras

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  1. Like
    Andras got a reaction from Chuankun in Analog Discovery 2 stopped working with Raspberry Pi 4   
    Hi @Chuankun,
    I had a similar problem. I have just bought and updated a Raspberry Pi 4 B and installed Adept Runtime 2.21.2, Adept Utilities 2.4.1 and Waveforms 3.14.3 without any issues.
    When I run Waveforms from the applications menu its Device Manager doesn't see my AD2, despite it's connected to one of the USB 3.0 ports.
    I tried both lsusb and sudo lsusb, and there was a difference, the latter showed more devices, so I also tried to run Waveforms from the command line sudo /usr/bin/waveforms, and it started to work!
    (I probably made a mistake when I installed the Digilent packages as root, and not as the user pi.)
  2. Like
    Andras reacted to modmix in Suggestion for improving the impedance analyzer   
    Good news: Impedance Analyzer v1.4.0.0 Available for Download
        "Impedance Analyzer for Analog Discovery 1 & 2 (this time tested with AD2)"
    Works with AD1.
    My AD2 is still on its trip ,-)
    Pls report your results.
    Ulli
  3. Like
    Andras reacted to fonak in Suggestion for improving the impedance analyzer   
    Hi Ferda
    I am currently at the stage of designing an external adapter PCB similar to this presented video (I read the whole post about it on eevblog). This adapter should at least solve some of the problems you're talking about (eg stronger output based on LT1210 or BUF634).

    PS. Do you have a link to the program that the author of the attached video use?
  4. Like
    Andras reacted to Ferda in Suggestion for improving the impedance analyzer   
    Hi All,
    I am a material science chemist and using impedance method to characterise the dielectric properties of some novel materials by paralel plate capasitor method. As you can imagine there are a few brands who produce decent instruments for these kind of measurements. But, with the developing technology it is possible to observe similar readings with AD-IA combination compared to old 100K$ instruments. I am also an electronic hobbiest and bought an AD2 just for testing the idea and compared the result with an instrument. On that time the IA board was not available but, the readings was very similar to a commercial instrument. Anyway, now with the IA option it is more easy to make measurements. But, the biggest problem with the current setup non-autoranging the resistor values. Sure, this can be overwhelmed by making some coding. However, the IA add-on board is very complex to modding, i.e. the realys have laching function which can not be released by applying reverse control logics. Furthermore, there are also several other lack of hardware functions, such as high output current, limited input impedance of the CH1/CH2 althoug the input opamps has very high imput impedance etc. Hence, I think in the first instance the IA board should have auto ranging function. This can be done by the DIGILENT engineers, which is out of my experience and I do not have time to understand communication protocol and commands for communication of AD2 with computer. The second development again can be done by digilent which can be a decent IA board (IA2). This second release should have higher WG current to measure lower impedances and high input impedance function to read high impedances (There is a video on You-Tube mentioning a basic board ).
    I think these add-ons can increase the importance of AD and Digilent which did a great job upto now.  Best wishes
  5. Like
    Andras reacted to attila in AD2 + DWF on Raspberry Pi using C# (.NET 5)   
    Szia @Andras
    Thank you for the dwf.cs observation. 
    See the following post:
     
  6. Like
    Andras reacted to attila in AD2 + DWF on Raspberry Pi using C# (.NET 5)   
    Szia @Andras
    The WF (application and runtime) is available for Linux ARM32 (armhf) and ARM64 (arm64):
    https://reference.digilentinc.com/reference/software/waveforms/waveforms-3/start
    For Linux you could try changing in the dwf.cs wrapper the DllImport("dwf.dll" to DllImport("libdwf.so" or DllImport("dwf.so" or DllImport("dwf"
    ... Sorry but I'm not familiar with .Net on Linux
  7. Like
    Andras reacted to Andrei Errapart in WaveForms SDK with C#   
    I am really sorry to interrupt you.
     
    In the process of cleaning up old hard drives I found my take on the C# interface to WaveForms SDK (from year 2014) and put it up on GitHub, https://github.com/Andrei-Errapart/WaveFormsSDK
    The difference is that I have taken the trouble to turn errors into exceptions, which some might dislike. Other than that it is also one-to-one mapping to the SDK.
    The license is MIT, which is quite permissive - many companies use libraries licensed under MIT.
  8. Like
    Andras got a reaction from attila in Analog Discovery 2 stopped working with Raspberry Pi 4   
    Hi @Chuankun,
    I had a similar problem. I have just bought and updated a Raspberry Pi 4 B and installed Adept Runtime 2.21.2, Adept Utilities 2.4.1 and Waveforms 3.14.3 without any issues.
    When I run Waveforms from the applications menu its Device Manager doesn't see my AD2, despite it's connected to one of the USB 3.0 ports.
    I tried both lsusb and sudo lsusb, and there was a difference, the latter showed more devices, so I also tried to run Waveforms from the command line sudo /usr/bin/waveforms, and it started to work!
    (I probably made a mistake when I installed the Digilent packages as root, and not as the user pi.)
  9. Like
    Andras reacted to 7M4MON in Analog Discovery 2 as Software Defined Radio?   
    How to install (I'm using Ubuntsu and GRC 3.7.11 with WX GUI.)
    at "gr-AD2_AnalogXx_Xxxxxx" directory
    $ mkdir build ↵
    $ cd build ↵
    $ cmake ../ ↵
    $ make ↵
    $ sudo make install ↵
    wxgui_.... blocks are not mine, installed with GRC 3.7.11.
    Before using my blocks, you should be install Waveforms and dwf (from pip)
  10. Like
    Andras reacted to fusionimage in Analog Discovery 2 as Software Defined Radio?   
    @Andrasyes, it works for me, but i just tested it for a second and didn't have any time yet for further testing. 
    did you compile install it with the following code?
    git clone https://github.com/7m4mon/gr-ad2
    cd gr-ad2
    mkdir build
    cd build
    cmake ..
    make
    sudo make install
    sudo ldconfig
  11. Like
    Andras reacted to 7M4MON in Analog Discovery 2 as Software Defined Radio?   
    I made the blocks for AD2 AnalogIn and AnalogOut.
    https://github.com/7m4mon/gr-ad2
    Please fork it!



  12. Like
    Andras reacted to attila in Network Analyzer versus Impedance Analyzer   
    Hi @Andras
    A. Comparing two different tools might not be the best option, it could give different results.
    B. At the moment the Impedance Analyzer interface takes control over the Supplies and DIO lines to control the IA Adapter.
    On the Adapter the negative supply and some DIO lines are unused.
    In the next software version I will add option to be able to control these.
    Having these you could use a small signal relay with ~5V control, similar to the ones on IA adapter but non-latching, to switch between the measured and control DUTs.
    https://reference.digilentinc.com/_media/reference/instrumentation/analog_discovery_impedance_analyzer_sch.pdf

    Edit:
    You could use the current software for plan B.
    First, in the Impedance interface using the Adapter option select the needed resistor value, then select "W1-C1-DUT...". This will release the Supplies and DIO lines to be used from other interfaces, and the latching relays on the Adapter will remain unchanged. Then you can use the Static IO or Negative supply for other purposes, to control the external relay...

  13. Like
    Andras reacted to attila in Network Analyzer versus Impedance Analyzer   
    Szia @Andras
    The WaveForms Sound Card option is solution for free... in case the audio IO limitations are suitable for the requirements.
    Here some IA measurements are compared between AD2 and Sound Card:
     
  14. Like
    Andras reacted to attila in Feature request: Importing frequency-domain data from .csv   
    Szia @Andras
    The wide/narrow trace toolbar can be toggled with this button and Import is added for the analyzers.
    https://forum.digilentinc.com/topic/8908-waveforms-beta-download/

     
  15. Like
    Andras reacted to attila in Network Analyzer versus Impedance Analyzer   
    Szia @Andras
    For this you don't necessarily need a script.
    In the interface you can set constant frequency (Start = Stop), specify a long Settle time and press Single.
    Like the following will run for 50 minutes, 100 samples at about 2/min rate, 30s + a few milliseconds due software processing.

  16. Like
    Andras got a reaction from Cleber Borges in Network Analyzer versus Impedance Analyzer   
    Before I continued my tests with beer, I wanted to make sure of two things:
    a, the amount of the sample fluid does not influence the impedance values
    b, the measurement itself does not change the sample fluid so that its impedance is changed at every measurement
    For case A, I made 3 references with 1 cup, 2 cups and 3 cups of tap water.  I used the same source and the same container for all the measurements.

     
    Then I made 3 other measurements of the same 3 cups of water.

     
    At this point I can conclude that the measurements are fairly harmless, there is only a small amount of change on the dataset after each consecutive measurement. I could probably use lower voltages, which could theoretically reduce the impact further.
    The amount of the test fluid does change the dataset somewhat, so I will keep that in mind when I go ahead with my further tests and I will try to keep the volume of the fluid fixed.
    As we could see from my previous post, the temperature is very important, so that's another parameter I will try to manage and keep constant between the tests.
  17. Like
    Andras got a reaction from Cleber Borges in Network Analyzer versus Impedance Analyzer   
    Hey guys,
    I've made some experiments that could be interesting for your as well. I put tap water into my ceramic container, I heated it to different temperatures and measured the impedance every 5 degrees.
    You can see the values between 60 ° Celsius (140 ° Fahrenheit) and 5 ° Celsius (41 ° Fahrenheit). Red is 60 Celsius, blue is 5 Celsius and there are 10 steps between them.

  18. Like
    Andras got a reaction from attila in Network Analyzer versus Impedance Analyzer   
    Hey guys,
    I've made some experiments that could be interesting for your as well. I put tap water into my ceramic container, I heated it to different temperatures and measured the impedance every 5 degrees.
    You can see the values between 60 ° Celsius (140 ° Fahrenheit) and 5 ° Celsius (41 ° Fahrenheit). Red is 60 Celsius, blue is 5 Celsius and there are 10 steps between them.

  19. Like
    Andras got a reaction from attila in Network Analyzer versus Impedance Analyzer   
    I did a quick experiment with different liquids. All of them are in a small ceramic container.
    The blues (Ref1, Ref2 and Ref5) are tap water.
    The red (Ref3) is salted water.
    The green (Ref4) is carbon-filtered tap water.

    I just put both the + and - wires of the Impedance Analyzer into the container and I made sure they are not directly connected.
    Here are the results:

    Cool stuff!
  20. Like
    Andras reacted to Cleber Borges in Network Analyzer versus Impedance Analyzer   
    hello @Andras ...
    My IA board (impedance analyzer) arrived a few days ago, but I did not even test it ... But now I have the AI board in my hands. Thanks for your attention.
    The IA board does not allow a reference electrode (RE) such as figure-item B. Such a scheme would be to not pass current between the working electrode (WE)  and a reference electrode (RE). It would be to measure more accurately and discount several other effects in a more automated way. This scheme is not necessarily mandatory.

    You can use the scheme of just two electrodes as you mention.
    I am a chemist and I do not have much knowledge of the electrical / electronic part. I imagine that your measurements reflect well the salinity of the water tested.
     
    Actually, I think this device - AD2 - could provide a lot of chemical information of Impedance measurement, but I just started reading about it.
    It's great to know that more people are interested in AD2 and EIS ... so we can build a source of information.
    Regards,
    Cleber
     
  21. Like
    Andras reacted to cephy in scripting waveforms network analyzer function   
    I want to automate the network analyzer function in waveforms using script.  I want to run the network analyzer every 5 minutes for 10 times (with the same settings) on the same RLC circuit and save the results (frequency, gain and phase) to a file.  Is there a way to write a script to automate this? 
    thanks
    rob
  22. Like
    Andras reacted to Grimmers in Analog Discovery 2 vs Raspberry Pi 3   
    Szia and Attila
    I got a Raspberry Pi 4 last week on release day (got the 2GB version as they sold out of 4GB in half a day) .  Just got it plugged into the Analog Discovery and it works!
    Not really tried it for long but it seems to work reliably, but only well on USB3.
    On USB3 port, first time it wasn't recognised, but tried again after swapping devices around a then it was detected.  Maybe it clashed with my wireless mouse dongle   When I tried USB2 port, it connected immediately but I found that every few minutes (max 5-10mins) it would throw a device error window and I would have to clear and reconnect.  Maybe RPi foundation kept the FTDI chipset for USB2 and used a new one for USB3 (Pi datasheet only says there is one chipset and it's not FTDI).    I will try and soak test tomorrow, but looking good on USB3.   So far it has been running 23mins with no apparent glitches, and Chromium tabs open.  Waveforms taking 13-20% of CPU in task manager.
     
  23. Like
    Andras reacted to Cleber Borges in Frequency Limitation on Impedance tool   
    Hello @attila
    Good Morning
    Thanks for your response and patience :-)
    I am a Professor of Chemistry  (University Researcher in Brazil) and I am interested in the area of:
    EIS - Electrochemical Impedance Spectroscopy  ( below SITE reference in [1] ).
    In an EIS study, the frequency region of 100kHz to 1uHz is very common.
    It is the current practice of this area.
    The amplitude of the signal is a few millivolts. Usually it's 10mV.
    So my interest in low frequencies and low amplitudes
    In WaveForms Help - AD2 (item 5: AWG) says:
    The resolution is ~0.7 mV for amplitudes above 1 V, and ~0.18 mV for amplitudes of 1 V and lower.
    Does the AD2 and sound card achieve a higher resolution than this?
    Because I see that the low frequency is not limiting but the signal resolution at 10mV seems to me to be near the limit.
    I am a layman in the subject and I am still starting in EIS
    but I think that the hardware and the software could also be very useful in this field :-) !!!
    Thanks again for your dedication!
    Cleber Borges
    [1] - https://en.wikipedia.org/wiki/Dielectric_spectroscopy
  24. Like
    Andras reacted to attila in Logic Analyzer: debugging I2C on Raspberry Pi   
    For the Protocol / SPI-I2C /Spy mode you should specify the approximate (or highest) protocol frequency which will be used to filter transient glitches, like ringing on clock signal transition.
    The Errors you get indicate the signals are not correctly captured.
    - make sure to have proper grounding between the devices/circuits
    - use twisted wires (signal/ground) to reduce EMI
    - use logic analyzer and/or scope to verify the captured data / voltage levels at higher sample rate at least 10x the protocol frequency
    Like here in the Logic Analyzer you can see a case when the samples are noisy:
     
  25. Like
    Andras reacted to attila in Save continous data to file in WaveForms   
    Szia @Andras
    At the moment you have WAV RIFF WAVE export under Scope/View/Logging/Script/Example.