The central control unit of the RealSimControl system is a single "master" controller board Mega2560 (Arduino2560) with RSC firmware uploaded to it once (until next firmware update).
All pins that are available in the CONFIGURATOR can be assigned for inputs/outputs or extensions
These signal lines are reserved for outputs only - LCD, 7-segment displays and LED drivers, see more in the related sections:
Note: These 8 pins are configured as outputs, so you may think about common precautions not allowing outputs overload when you mistakenly short the pin to the GND. You can add serial safety resistors (30 - 100 ohm to each signal line) for current limiting, but in RealSimControl firmware these outputs are always in "low level" and for only a very short period of program time they can be in a high level state, so it's unlikely you will overload the address line.
NOTE: The +5V output pin can be used as a source for all multiplexers connected to RealSimControl bus and also it can be used to power some low-current output devices. See more detail about system powering here.
You can create a flexible modular system and have full set of input controls for any complex cockpit and easily expand it by adding more extension modules at any time.
The RSC firmware is a heavily optimized program code, written from scratch (without using third-party Arduino libraries) to handle a large number of inputs, synchronize data control for a large number of different input/output devices, exchange data between plugin and “slave” boards.
RSC interface doesn't allow to use the controller board as a "usual" Arduino and users can not add any custom code, as there is no Arduino sketch, and the plugin uploads firmware directly to the board. At this moment the Atmega2560 is used as a convenient and easily available controller platform for RSC firmware.
The system is designed to work with Roman's SimVimX plugin. The latest stable RSC firmware is usually included in the plugin, and it's' usually updated very rare (once in a few months or year), even if the SimVimX plugin or database is frequently updated. The RSC Firmware is loaded only once, directly from the SimVimX plugin menu, as described below or in the SimVimX page.
But sometimes I can provide the latest beta Firmware version on the Boosty blog or Patreon as additional file that regular subscribers can download and place it to the SimVimX plugin folder after that it will be uploaded automatically. Without this file the in-built firmware will be used.
The RSC firmware needs to be uploaded to the master board from the plugin menu by the user just once at first time to the "fresh" Mega2560 board (If you have NO previously uploaded firmware).
If you need to upload the Ethernet firmware version set the "Ethernet" checkbox before pressing "Upload".
On successful connection you will see the messages "Master Board: Connected (USB/LAN)" and "Configured: 1 Input, 1 Output"
This means your board is working correctly, and you can start wiring all input controls and output devices to the controller and use the Configuration tool to assign all of them, but before you can run a simple test to make sure:
Reload Config button reloads all SimVimX configuration, it should be used when you have saved a new or edited data configuration file.
The plugin checks the currently used firmware version on connection, and if it needs updating (the new stable firmwre is included to the plugin or plugin finds a beta RSC file in the plugin folder), the program uploads the new firmware to the board and then establishes connection. There's nothing more for you to do for the serial USB version.
You can use any ofthe Mega 2560 based controller boards available on the market. In the photo you can see three mini controller boards that are tested with RealSimControl/SimVimCockpit, the firmware was uploaded to every of these boards from SimVimX plugin menu without any problems.
There are some other atmega2560 controller boards on the market like "Crumbuino-Mega", various "core" modules. You can find them yourself using such keywords as "2560 core", "atmega2560 mini", etc.