Mode Control Panel

MCP is almost finished now. The only few things not installed yet are smoked display filters, MA covers and A/P disengage switch. Later I will also replace knobs – current are 3D-printed with my old Solidoodle in poor resolution. And screws will be painted offcourse.



Front panel was ordered from Simworld. It happened before I bough own CNC machine. Probably, panel quality is the best available on the market, but not perfect at all. Paint quality is poor (it can be clearly seen when backlight is on), engraving is displaced relatively to holes. 7-segment display screens are of different thikness and translucency!

On the other hand metal back panel is awesome.


MCP is being driven by Arduino. I’m currently working on custom firmware and routing software. The idea is to build universal hardware/software interface to use cheap Arduino board (Mega2560 for as low as $10 on eBay).

There are 3 PCB’s connected to arduino:

1. 7-segment driver board based on MAX7219 drivers

2. OUTPUT board using 74HC595 shift registers and ULN2803 transistor arrays. All lights on MCP are powered by 12V. OUTPUT board also has PWM input, that allows to control lights intensity (not backlight). Output board also contains transistor-diode 28V circuit for A/T disarm solenoid.

3. INPUT board using MCP23S17 IO expanders. That’s perfect solution with price just above 1 Euro. It supports up to 16 input (or outputs) with pullup’s so it’s not required to add any resistors outside and simplifies overall circuit. INPUT board also contains ATTINY2313 with custom firmware alowing to operate 6 rotary encoders. Encoder type (incremental or gray-codeed) can be definded in router software.

A/T disarm is original (and in new condition!) switch I found on eBay for US$100.



Korrys are of very simple construction: pushbutton with lights is mounted on PCB. Faceplate is attached to 3D-printed button case. It’s divided inside allowing separate backlight for title and status indication.


With PROSIM:737 it works almost perfect. The only problem I found is small delay between any input and getting result on display or light indication. It seems, that delay is result of communication between MCP and main PROSIM modules.

It can also be connected to iFly and NGX, but FSUIPC support is not fully implemented yet in routing software.

A/T disarm video:

Brightness control using 2 PWM outputs and native dimming support in MAX7219 and routed to analog input on different Arduino by software.

5 thoughts on “Mode Control Panel”

    1. Thank you! I’ve almost finished now beta which can be shared without shame )) Hope to finish till end of march.

  1. Hi!

    Great job with the MCP. I am building one myself. Can i ask what type of Rotary encoder you use and where to order them?

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