System2 Panel Controller

The Panel Controller is a System2 board designed for mimic panels and control desks. It connects your physical push buttons and toggle switches to the rest of your layout, and drives LEDs to show the current state of points, signals, and track occupancy.

It provides:

• 16 input channels — for buttons, toggle switches, occupancy sensors, and points-position sensors.
• 16 output channels — for LEDs, with individual RGB colour control and background-lit or active-lit modes.
• Dual networking — a wired CAN bus connection and Wi-Fi, either or both at the same time.
• JMRI & MQTT integration — connect to computer-based layout control software without extra hardware.
• Over-the-air updates — the board updates itself from the internet, so it is always improving.

System2 is a modern, British-designed control platform for model railway layouts of every size. It was built from the ground up to be simple for newcomers, yet powerful enough for the largest exhibition layouts. System2 is the exclusive control system behind Pete Waterman's The Grand Challenge — holder of the Guinness World Record for the largest portable model railway at 694.9 metres of track.

Every System2 board carries its own built-in administration page, so there is no single computer or central controller that everything depends on. You configure each board from any web browser on a phone, tablet, or PC — no special software to install, no apps to download.

This guide covers Release 25 and later of the Panel Controller firmware. If your board is running an earlier version, you can update it over the internet in minutes (see Software Updates).

Before diving into the software, let’s get your Panel Controller physically connected. This section walks you through the board layout, what each connector and button does, and how to wire boards together on the CAN bus.

Board Layout

The annotated photograph below shows a Panel Controller with all its connectors and key features identified.

What You Need

• A 12 V regulated DC power supply (minimum 500 mA per board).
• Twisted-pair signal cable for the CAN bus — standard 26 AWG telephone or network cable works well.
• A small flat-blade or Phillips screwdriver for the screw terminals.
• A 2.4 GHz Wi-Fi network — the ESP32 radio does not support 5 GHz. Most home routers broadcast both bands; just make sure the 2.4 GHz band is enabled. The board also needs internet access if you want to use over-the-air software updates.
• A phone, tablet, or PC with Wi-Fi for configuration.

Wiring a Single Board

1. Connect your 12 V power supply to the 12V and GND positions on the green screw terminal. Observe polarity — the labels are printed on the board.
2. If this board will communicate over the CAN bus, connect a twisted-pair cable to the H and L terminals. Make sure CAN H goes to CAN H on every board, and CAN L goes to CAN L.
3. Plug in your pre-wired buttons (supplied with the starter kit), your own switches, or sensors as needed. You can mix any number of different types in any position.
4. Connect your LEDs to the OUTPUT pins. Set the NORM/LEDS/COMP jumper to match your LED wiring configuration (see Configuring Your Ports).
5. Power on. The PWR LED should light, and after a few seconds the board will either connect to your Wi-Fi network or start its own hotspot (see Getting Connected).

When your Panel Controller is brand new (or after a Wi-Fi reset), it does not yet know your Wi-Fi network name and password. It will create its own temporary hotspot so you can tell it which network to join. You only need to do this once — the board remembers your Wi-Fi details permanently, even after power cuts and software updates.

Even better, once one board knows your Wi-Fi credentials you can share them across the wired CAN network to every other System2 board with a single button press (see Sharing Wi-Fi Credentials). So in practice, you only ever type your Wi-Fi password once for your entire layout.

Once connected to Wi-Fi, open a web browser and navigate to your board. The main page gives you complete control of your Panel Controller. It is divided into clear sections, from top to bottom:

The port configuration table is the heart of the Panel Controller. Each of the 16 rows represents one physical input (button/switch) and one physical output (LED) on the board.

Input Ports (left side)

Input Types

Output Ports (right side)

Shortcuts & Time-savers

Setting up 16 channels does not have to be slow. The interface includes several shortcuts to save you time:

Typing V-Port numbers one by one for all 16 channels can be tedious. EasyConfig lets you assign a complete block of V-Port addresses in one click. This feature is especially useful when setting up multiple boards — you can configure each board without having to think about individual V-Port numbers. It saves significant time and avoids mistakes when you just want to get going quickly.

Select a board number from the dropdown. The system automatically assigns a sequential range of V-Ports to all 16 input and output channels based on that board number. Board 1 starts at V-Port 1, Board 2 at V-Port 17, Board 3 at V-Port 33, and so on.

Roaming

Many layouts, especially exhibition layouts, use more than one Wi-Fi access point to cover a large area. Roaming tells the board to periodically check whether a stronger access point is available, and seamlessly switch to it if so.

We recommend leaving Roaming on (the default). Even if you only have a single access point today, roaming causes no harm and means your boards are ready to take advantage of a second access point if you add one later. With roaming on, the board scans every five minutes and only switches if it finds a significantly stronger signal, so there is no disruption during normal operation.

Boot Delay

On large layouts with many boards, enabling Boot delay adds a short pause (1–15 seconds) before the board connects to Wi-Fi at power-on. This staggers the Wi-Fi connection requests and avoids overwhelming your router when everything powers up at once. This is probably not necessary unless you have a particularly slow router and a large number of boards — say 30 or more. Most users can leave this off.

Once one Panel Controller is connected to your Wi-Fi, you can send those credentials to every other System2 board on the wired CAN network with a single button press. This means you never need to set up Wi-Fi on each board individually.

Release 25 of the Panel Controller firmware is the most feature-rich update yet. Here is a quick summary of everything that’s new or improved.

New Features

Improvements

System2 uses a concept called Virtual Ports (V-Ports). Every switch, sensor, LED, or servo on your layout is assigned a V-Port number (from 1 to 60,000). When a button is pressed on one board, it sends its V-Port number across the network. Any other board listening for that same V-Port reacts — it really is that simple.

Data travels across two networks using three protocols:

The Protocol button near the bottom of the main page lets you choose how your board communicates with other devices. Tap it to cycle through the three options:

When using Native MQTT or JMRI, you also need to provide the address and port of an MQTT broker (a small piece of software that routes messages between devices — Mosquitto is a popular free choice).

Configuring the MQTT Broker

When you select Native or JMRI as the protocol, the header bar reveals two extra fields: Broker and Port.

1. Tap the Protocol button until it shows Native (for System2 MQTT) or JMRI.
2. In the Broker field, enter the hostname or IP address of your MQTT broker (e.g. broker1.local or 192.168.0.100).
3. In the Port field, enter the broker’s listening port. The standard MQTT port is 1883 and is filled in by default.
4. Click Save Changes, then Reboot to activate the new settings.

The status log will confirm the protocol change and remind you to save and reboot.

Native MQTT — How It Connects

In Native MQTT mode, boards communicate wirelessly through an MQTT broker instead of the CAN bus. Each board connects to your Wi-Fi network and publishes its V-Port states to the broker. Other boards subscribe to the same topics and react accordingly — the broker handles all the message routing.

JMRI Mode — Computer-Based Control

In JMRI mode, the boards communicate with JMRI (Java Model Railroad Interface) running on a computer. JMRI connects to the same MQTT broker and uses standard turnout and sensor topics. Your boards appear as native JMRI accessories — no extra hardware or adapters required.

The navigation links give you full control over your settings:

Click Show Charts at the top of the main page to reveal four real-time charts covering the last 10 minutes of activity. They update every 5 seconds. Click on any chart to expand it for a larger, more detailed view — click outside the expanded chart to close it.

Software updates are one of the most important features of the Panel Controller. Unlike traditional model railway electronics that are frozen at the version they ship with, your Panel Controller can update itself over the internet, gaining new features, improvements, and fixes long after you purchased it. This future-proofs your investment — the board you buy today will keep getting better over time.

The system checks for updates automatically when it starts. If a new version is available, you will see it on the Software Update page, accessible via the Update Firmware link on the main page.

What you see on the update page

When updates are available, the page shows a complete release history with summary descriptions of every version released since the one you are currently running. You can expand each release to read detailed notes about what changed.

How to install an update

1. Navigate to the Software Update page by clicking Update Firmware on the main page.
2. The page will check for the latest version automatically and tell you if you are up to date.
3. If an update is available, click Install Latest Update (or choose a specific version from the history list).
4. The board will download and install two files — the firmware (1/2) and the filesystem (2/2). This takes 4–8 minutes depending on your internet speed. Do not power off the board during this process.
5. Progress is shown in the Update Log with percentage updates. The onboard LED will flash erratically during the download.
6. When complete, the board reboots automatically onto the new version.

Security

Every firmware update is digitally signed using RSA-PSS cryptography. The board verifies the signature and signing key before applying any update. This ensures only authentic, authorised software from MegaPoints Controllers can be installed.

Can I go back to an older version?

Yes. The full history view lets you install any previous release. Simply click the Install button next to the version you want. You can roll back to any version from V25 onwards — that is when we introduced the new update system that supports version history and rollback.

The Network Monitor (accessible from the navigation links) is a powerful diagnostic tool that shows you every CAN bus message in real time. It is invaluable for troubleshooting or simply understanding how your layout communicates.

Each row in the monitor shows:

The monitor also resolves board names automatically — when it recognises a CAN ID from a board that has reported in, it shows the board's hostname for easy identification.

The Status Log at the bottom of the main page shows live system messages as they happen. It is the first place to look if something is not behaving as expected.

Typical messages include:

• Report messages — other System2 boards announcing their presence on the CAN bus, with their type, software version, and IP address.
• Announce messages — boards identifying themselves by name, location, and version (clickable links let you open their admin page directly).
• Protocol changes — confirmation when you switch between CAN, Native MQTT, or JMRI.
• Save confirmations — a green tick confirms your settings were saved successfully.
• Warnings and errors — colour-coded messages if something needs attention (e.g. weak Wi-Fi signal).

Connection Loss

If the browser loses its connection to the board (for instance if the board reboots or Wi-Fi drops briefly), a clear yellow banner appears at the top of the page and the board automatically attempts to reconnect.

We’re opening up the boards for anyone with the appropriate skill set to play with. The Panel Controller includes a full REST API that lets you read and control the board programmatically. If you enjoy scripting, building custom dashboards, or integrating with home automation systems, this is for you.

You can use the API from any tool that speaks HTTP — a web browser address bar, a command line with curl, Python scripts, Node-RED, or even a smartphone app. All responses are in JSON format.

Quick examples

Replace panel-64ee04.local with your board's name or IP address.

Check board status

GET http://panel-64ee04.local/api/status

Returns hostname, IP, software version, protocol, uptime, and more:

{
  "hostname": "panel-64ee04",
  "ip": "192.168.0.63",
  "swVersion": 25,
  "protocol": "CAN",
  "uptime": 86400,
  "location": "Baseboard 25"
}

Read all 16 channels

GET http://panel-64ee04.local/api/channels

Returns an array of all channel configurations and current states.

Toggle a channel

GET http://panel-64ee04.local/api/channel/3/toggle

Toggles channel 3 on or off and returns the new state. You can even do this from a browser address bar!

Change a setting from the browser address bar

GET http://panel-64ee04.local/api/set?location=Signal+Box+North&wifiRoaming=1

Updates one or more settings in a single request.

List all boards on the network

GET http://panel-64ee04.local/api/boards?probe&json

Sends a network probe, waits 3 seconds, then returns a JSON list of every board that responded.

Back up your settings

GET http://panel-64ee04.local/api/settings/export

Downloads a complete backup of all settings as a JSON file.

Full API endpoints

For complete API documentation, refer to the dedicated API reference document available through the Documentation link on your board's main page.

Built for reliability

The System2 platform has been engineered with robustness as a top priority. The Panel Controller is the same system trusted to run The Grand Challenge, Pete Waterman's Guinness World Record-holding portable layout with nearly 700 metres of track and dozens of System2 boards operating simultaneously.

What makes it robust

Testing and quality

Every release goes through extensive testing before publication. The firmware includes comprehensive CAN bus stress testing, Wi-Fi failover testing, NVS integrity verification, MQTT broker disconnect/reconnect cycles, and over-the-air update validation including signature verification. The Status Log, Network Monitor, and live charts provide full visibility into the system's operation, making it straightforward to verify that everything is working correctly.

Specifications

The CAN bus is the wired backbone of a System2 layout. It runs at 125 kbit/s over a simple two-wire connection, and is extremely reliable — the same technology used in cars, aircraft, and industrial machinery.

Each board on the CAN network needs a unique CAN ID. With Auto CAN ID turned on (the green toggle), the system manages this for you automatically. If two boards accidentally share an ID, they will detect the collision and pick new, unique IDs within seconds.

Connecting Multiple Boards — the CAN Wiring

The CAN bus is a simple two-wire network that connects all your System2 boards together. It carries switch states, LED commands, and management messages between boards at 125 kbit/s. The wiring is straightforward: run a twisted-pair cable from board to board, connecting H to H and L to L in a daisy-chain.

The simplest setup is two boards connected by a single cable:

When you add more boards, they simply tap into the same pair of wires. The CAN bus is a linear bus — branch it out from board to board rather than running separate cables back to a central point.

Termination Jumpers

Every System2 board has a built-in 120 Ω termination resistor that is activated by a small jumper on the board, labelled TERM. The CAN bus standard requires exactly two termination resistors — one at each physical end of the bus cable. The rule is simple:

• First board on the bus → jumper IN.
• Last board on the bus → jumper IN.
• Every board in between → jumper REMOVED.