First panel using LED multiplexing

Now that I’m able to read values from P3D and send them to my Arduino Uno board, I want to prototype a simpit panel: the main annunciator panel. It consists of 20 LED notifications, organized in a matrix of 5 columns and 4 rows. The module needs to support:

  • lighting up individual LEDs
  • lighting up all LEDS at the same time (without frying my Arduino board 😳 )

King Air 350i main annunicator panel contents

I will follow this tutorial to get it working: (although I’m in the impression that there are some parts missing in this tutorial). Addional source:×8-LED-dot-matrix-with-MAX7219-module/

Note: I will not pay any attention to the looks of the module at this time. Since I have jack sh*t experience with all these things, I just want to verify if the concept could work:

  • Reading from P3D specific values into a Java program
  • Applying the business logic in that application to decide if based on the values read an annunciator should light up
  • Sending the output to the Arduino Uno board
  • Interpreting the output on the Arduino Uno board
  • Enable the related LED

Things to think about:

  • All multiplexing matrices have equal rows and columns (to maximize the number of LEDs per pin used on the Arduino board, e.g. 8×8 LEDs). But my matrix will have 4×5 LEDs. This will consume more pins that required, unless I make it a 5×5 matrix and assign the remaining 5 LEDS to another (annunciator) panel (see next point).
  • There are two annunciator panels; will I use one Arduino to control both or will I use separate Arduino boards.
    • One board
        • Pro’s
          • Saves one USB port on my computer
          • Java program has to communicate with one less Arduino board
          • Lower cost (an Arduino board cost about €25)
        • Con’s
          • wiring per board will be a lot more complex
          • Draws more current (maybe too much)
  • How many LEDs should be used per annunciator to ensure the notification remains visible in daylight conditions?
  • Can I use different color LEDs in one circuit (these have all a different voltage/current requirements)?


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