No1sonuk

Did you know this was a thing? I'm also going to look into creating a 2-seat version of the switch function.

Are you using blocking diodes in the matrix?

It's possible that's a legal liability thing.

The old version still works (I use it), but there won't be new modules added. DCS UFC X is a newer pay per module version.

Start a separate thread in this forum and we'll see what we can do.

What's your hardware setup?

It could be electrical noise. Try this: The resistors shown dotted aren't necessary - DCS-BIOS turns on those in the Arduino.

One problem you'll have is that the full rotation of the A-10 HSI is 0-65535, but the common data magnetic is 0-359. It looks like the code you have is designed to work with 0-65535 input. Try changing the value shown below. If that fails, try writing a stepper routine that takes a position number, and send it from a normal DCS-BIOS code block.

Build a stand...

As mentioned in Discord, which switches are they? It sounds like you were drawing too much current and were lucky not to blow the Arduino's regulator or I/O pins. The "bad burning smell" is the stage just before the smoke escapes!

OK. That should compile. What error message is it giving? However, I'm not sure that code will do what you want. There's nothing stopping the MASTER_CAUTION_RESET_SW toggling every loop while the button is down.

How are you trying to do it? The format is: sendDcsBiosMessage("MESSAGE", argument);

DCS-BIOS will natively work only with the ports ON the processor. If you want to use more through multiplexers and expanders, you have to write all the code to handle that yourself, then use the sendDcsBiosMessage function in DCS-BIOS to send the switch signals to DCS. You MIGHT be able to do it with a Nano using a matrix, but you're pushing it for that many inputs, AND remember that you CANNOT use pins D0 and D1 AT ALL with an Arduino running DCS-BIOS because they are used for the USB comms. MAX7219 LED drivers are a popular choice. 64 LEDs from one device. They can make eight 7-segment (plus decimal point) numerical displays or an 8x8 matrix, and a few can be "daisy-chained" to save IO pins. There's also the addressable LEDs - commonly called "Neopixels" after Adafruit's implementation of them.

It might be the routing of the wires as much as the length if it's noise.

Sounds like electrical noise on the wires. Is the wire run to the Arduino long? Try twisting all 3 wires together. Another thing to try is a 100nF (or similar) capacitor between each Arduino input and GND.