Connecting to OpenBCI using Adafruit nRF52

AlzaroAlzaro United States
in Build-it-yourself
Hi there,
I am transferring from the Ganglion board to an Adafruit nRF52832 board.  I believe I have successfully changed over the Simblee commands in the firmware for the Ganglion to the equivalents for the nRF52. However, when I try connecting to the OpenBCI, Hub crashes with a fatal error saying it "Cannot read property 'once' of null."
Additionally, when I run the software from Processing, error 402 comes up indicating a failure to connect to the board.

OpenBCI_GUI::Control Panel: Playback history file not found or other error.
The file "SavedData/Settings/UserPlaybackHistory.json" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
Hub: processConnect: made it -- 36589 code: 402
Error in processConnect: RESP_ERROR_UNABLE_TO_CONNECT
error, disabling clientEvent() for 127.0.0.1
java.lang.NullPointerException
at OpenBCI_GUI$Hub.processConnect(OpenBCI_GUI.java:13364)
at OpenBCI_GUI$Hub.parseMessage(OpenBCI_GUI.java:13269)
at OpenBCI_GUI.clientEvent(OpenBCI_GUI.java:12941)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at processing.net.Client.run(Unknown Source)
at java.lang.Thread.run(Thread.java:748)
Client SocketException: Connection reset

I am using a SRC BLE dongle for my Windows 10 machine, and I understand the BLED112 may be better.  Would changing dongles help in this case?
Is there somewhere deeper in the code (perhaps in the GATT protocols) that can be accessed or changed.  Is it something that could be adjusted at the Firmware level instead?

Thank you for your help.

Comments

  • wjcroftwjcroft Mount Shasta, CA
    Alzaro, hi.

    The BLED112 dongle is the recommended dongle for Ganglion. Previously CSR (Cambridge Software Radio) based dongles were recommended, but these required sometimes problematic setup with the Zadig utility. I have not heard of 'SRC' dongle. BLED112 costs about $10 and you can find it at electronics distributors such as Mouser, Digikey, etc.

    William

  • AlzaroAlzaro United States
    Thank you William,
    I mean I was using a CSR dongle.  With that dongle, the Ganglion board I have will connect without issue, but the custom board I am using will not.
    I will try using a BLED112 type dongle.
    Are there other recommendations you have?

    Alzaro
  • wjcroftwjcroft Mount Shasta, CA
    Have you tried the dongle you have on other laptops / OSes? On Mac, most of the times those can run with the builtin Bluetooth hardware. 

    Not sure if the BLED112 will resolve your issue, but worth a try.

    From your traceback in the original post, it looks like the Hub might be getting some BLE message that it does not understand, resulting in the null pointer exception. Can you look at that section of code, or perhaps printout more debug info in that area to figure out what the nRF52 was sending that the Simblee was not? Have you checked online for summaries of differences?


    Can you turn off the Bluetooth 5.x features of the nRF and drop back to 4.x?

    Etc.

    William

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