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Base Boards — Gateway/Bridge & PanelGroup

Two reusable base boards anchor every OpenSkyhawk controller. Instead of designing each controller from scratch, every panel builds on one of these shared foundations: they carry the common circuitry — power, CAN, the microcontroller, status LEDs — and break out the spare pins on headers, so a new panel only adds the parts that make it special.

  • Gateway/Bridge — the cockpit's single head node: the one board that talks to the PC.
  • PanelGroup base — the workhorse sub-node that most panels start from.

Both share the same microcontroller footprint, the same CAN transceiver, the same 3.3 V regulator, and the same status-LED scheme, so once you know one board you know the foundation of every board in the cockpit.

What every base board gives you

  • CAN bus, in and out — two pass-through bus connectors carry power and CAN from board to board. A jumper switches in the 120 Ω termination, so any board can sit at the end of the chain with no separate terminator.
  • Its own 3.3 V — takes 5 V off the bus and regulates it locally; the 12 V rail passes straight through for backlighting.
  • Programming + diagnostics on headers — a 5-pin SWD header (with reset, for reliable attach) and a 3-pin serial console.
  • Status at a glance — dim, silk-labeled status and power LEDs grouped in one cluster on the front face, driven by firmware.
  • Spare pins broken out — leftover microcontroller pins land on a 0.1″ header for prototyping and third-party use.
  • Standard mounting — four M2.5 corner holes, the standard screw across the whole cockpit.

Full electrical detail

This page is the overview. For exact pinouts, net labels, and the complete BOM, open the KiCad projects in the repo under PCB/Base/ — Gateway_Bridge/ and PanelGroup_Base/.

Gateway/Bridge — the head node

The one board that connects to the PC over USB. It pairs two microcontrollers on a single PCB: an RP2040 that presents the cockpit to the PC as a USB game controller, and an STM32 that runs DCS-BIOS and acts as the CAN bus master. Every other board in the cockpit reports through it.

Board render coming

A 3D render of the finished board will go here once it's through PCB layout.

Gateway/Bridge base board schematic — RP2040-Zero SimGateway and STM32 PanelBridge sharing the main bus, with the UART link between them, the CAN transceiver, regulator, and connectors
Role USB-HID + DCS-BIOS head node, CAN bus master
Node ID 0 (the master)
Microcontrollers RP2040-Zero (USB side) + STM32F103 (CAN side)
PC link USB-C on the RP2040 module — HID device 0x2E8A / 0x4134
Power 5 V from the bus; the RP2040 runs from USB

Highlights

  • One head node for the whole cockpit — a single USB cable to the PC carries both the HID controller and the DCS-BIOS data stream.
  • Two chips, one job each — the RP2040 owns USB/HID, the STM32 owns CAN and DCS-BIOS. They talk over a short serial link, and their power supplies stay independent (sharing only ground) so neither can back-feed the other.
  • Local display ready — both of the STM32's I²C buses are brought out, handy for a small status OLED or a sensor on the head board.
  • Status cluster — five LEDs (power, plus red/green for each of the two chips) show link and activity state at a glance.

PanelGroup base — the panel workhorse

The board most panels start from: a generic CAN sub-node that reads switches and drives lighting. Give it a node ID, wire your panel's switches and LEDs to its expansion headers, and it joins the bus.

Board render coming

A 3D render of the finished board will go here once it's through PCB layout.

PanelGroup base board schematic — generic STM32 CAN sub-node with two I²C buses carrying interrupt lines, two PWM backlight zones, the CAN transceiver, regulator, and connectors
Role Generic CAN sub-node — switches in, lighting out
Node ID 1–63, set per build in platformio.ini
Microcontroller STM32F103
I/O expansion two I²C buses (MCP23017 / ADS1115), each with interrupt lines
Lighting two PWM-dimmed backlight zones

Highlights

  • Drop-in panel foundation — most panels need nothing more than this board plus their switches and LEDs.
  • Two expander buses — two independent I²C buses, each carrying its own interrupt lines, drive the GPIO expanders (MCP23017) and analog inputs (ADS1115) that read a panel's controls.
  • Backlighting built in — two PWM-dimmed lighting zones, fed from the always-on 12 V bus, so panel backlights dim straight from firmware.
  • Wide-open breakout — the full field of spare microcontroller pins (analog, PWM, digital) is broken out for one-off controls and custom panels.

Where these live