VRMAX radio+ panel release

I am glad to announce the release of the VRMAX radio panel. Initially I thought it will be a separate device, but after actually building it and making some changes in the process, I decided that nothing prevents it from being a mod to the AB412 collective head. If you have one already, you just need to reprint and replace the bottom part of the housing, and tie and solder the radio panel combined i2c cable to that of the 412 head.

I have made a few changes since when the video from the previous post was filmed:

  • panel mode switch now respects the stack selector switch position; this means we now have 6 more button sets for 4 radio panel knobs to map to some useful functions.
  • I noticed that OBS and HDG knobs were way too slow to be operated comfortably, so a new continuous turn mode was added: it will be making a lot of short button presses on each knob step, resulting in OBS knob continuous rotation (up to around 30 degrees). Pressing the button of the knob switches between 1-press-per-step and continuous modes, a button press in the latter stops rotation. This works for OBS and DIR GYRO knobs.
  • After some thinking, I changed the behavior of radio panel knob pushbuttons: they are now mapped to 3 different joy button sets depending on the stack selector switch position. This allows us to use 2 top buttons for ACT / STBY buttons of the selected radio ( 1 for COM, 1 for NAV), and 2 other buttons – for audio panel mute / unmute buttons (for currently selected COM and NAV)! This is useful, when you have tuned some AWOS frequency in advance on your second radio, and want to mute it until you’ll be close to the airport, or when you want to make sure you’re tuned to the correct VOR and check that you’re actually receiving the signal from it.

To test the new panel, you can use this web based tool: https://html5gamepad.com/. It displays all of its 154 buttons properly 😀

Here’s how the head looks when installed onto the single collective:

You can find the assembling manual here. I will be making a tutorial and a flight video shortly.

Stay tuned!

11 Replies to “VRMAX radio+ panel release”

  1. Hi,

    I’m currently assembling the VRMAX panel, I’m wondering about step 11 where we connect the ‘green’ cable from step 8. Wire #3, which is connected to one side of the encoder press button is said to connect back to arduino GND, but the other side of the encoder press button is already at GND, so I’m not sure what we’re achieving?


  2. Hi Alexy,

    I’ve come across one more issue, that I *think* is software, but I don’t know where to look.

    On the radio panel, the RADIO_MODE_SWITCH_LOWER_POSITION_JOY_BUTTON is showing up in joy.cpl as button 10 which matches the a_configuration file default.
    My issue is that the middle xpdr setting XPDR_MODE_C_JOY_BUTTON is also coming through as button 10 where it should be button 9. The other two positions on this switch come through correctly as 7&8 . Testing with a multimeter, I’m confident the wiring is ok.

    Any suggestions on where to look?


    1. Ok, I got around the issue by adding a -1 in m_vrmax_panel:
      simchair_aux1.setButton(XPDR_MODE_C_JOY_BUTTON -1 , 1);

      Not being a programmer, I’m not sure that’s the right thing to do, but at least XPDR_MODE_C_JOY_BUTTON now matches the config file as button 9 in joy.cpl.

      1. Hi Jeremy! I am not sure what’s happening, but I found out 2 things:
        1) My XPDR_MODE_C_JOY_BUTTON shows correctly as button 9
        2) For some reason, if I uncomment #define RADIO_PANEL_SETUP, it stops compiling.
        This is really strange as I remember it working! Does it work for you? What version of the software do you use?

        I guess I broke it with my latest commit. Will fix it as soon as I have a bit of free time =)

        Thanks for noticing it! The device is very new and barely tested yet.

  3. I also got the compile error. I had to change an ‘else if’ to ‘if’ just after the #endif line.

    Again, I’m not sure of the flow on effects of that. I know enough Arduino to be dangerous, that’s about all…

    Thanks for your work on this, it’s awesome.

    1. When I did it, for some reason joysticks stopped showing in joy.cpl 😀 Have you seen this behavior too? Are you using the very latest IDE version? I think we’re close to limits of the board, but maybe there’s something else.

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