Building a custom flight data display is one of the most rewarding projects you can undertake for your flight simulator cockpit. It transforms a static setup into an immersive, interactive environment where critical parameters like altitude, airspeed, heading, and vertical speed are always visible at a glance. Off-the-shelf instruments exist, but they often lack flexibility, or they don’t match your cockpit’s specific layout or aesthetic. A DIY display gives you complete control over the size, data fields, fonts, colors, and even the ability to add alerts or custom logic. This guide covers everything from component selection to advanced features, helping you create a display that feels factory‑built.

Core Components and Selection

Every custom display starts with two primary building blocks: a microcontroller to process data and a display module to show it. The choices you make here determine the display’s performance, complexity, and cost.

Microcontroller Options

The microcontroller acts as the brain, reading data from your simulator and driving the screen. The three most common families are Arduino, Raspberry Pi, and ESP32 boards. Here is a comparison to help you decide:

  • Arduino (Uno, Mega, Nano): Best for simple OLED or character LCD displays. They are inexpensive, well‑documented, and work with many display libraries. However, they lack built‑in Wi‑Fi/Ethernet and have limited memory. Ideal if you plan to use a wired connection to the simulator PC via USB serial.
  • Raspberry Pi (Zero, 3B+, 4): A full Linux computer capable of running Python and handling complex graphics (e.g., glass cockpit displays). It can also run simulator‑side scripts directly if installed inside the cockpit PC. The Pi is overkill for a single small display but shines when you need multiple screens or touch interfaces.
  • ESP32: The sweet spot for many cockpit builders. It has Wi‑Fi and Bluetooth built‑in, allowing wireless data transmission from the simulator. It also includes two cores, sufficient RAM for larger TFT displays, and is nearly as cheap as an Arduino. The ESP32 can run Arduino sketches or MicroPython.

For most builders, an ESP32 or an Arduino Mega (for its extra I/O pins) is the best starting point. If you want a wireless, low‑cost, high‑performance option, the ESP32 is the way to go.

Display Modules

The display you choose defines how much information you can show and how crisp it looks. Popular options include:

  • OLED (0.96″ or 1.3″): Small, high contrast, and extremely fast. Great for one or two data lines (e.g., altitude and speed). They use I²C or SPI and consume very little power. Perfect for a compact “instrument” panel.
  • Character LCD (16×2 or 20×4): Cheap and easy to use, but limited to monochrome text. Good for prototyping or a simple standby display.
  • TFT (1.8″ to 5″): Full color, capable of rendering gauges, tapes, and artificial horizons. They require more memory and a faster processor (ESP32 or Pi). Look for ILI9341 or ST7735 drivers for Arduino‑compatible models.
  • E‑ink: Extremely low power and sunlight‑readable, but slow to update. Not ideal for rapidly changing flight data.

Start with a small OLED for your first build to learn the basics, then scale up to color TFT for a more realistic instrument.

Power and Wiring Considerations

Reliable power is often overlooked. A stable 5V supply is essential. Many displays draw 100–300 mA, and a TFT with backlight can exceed 500 mA. Use a dedicated USB power adapter or a regulated 5V bus if you have multiple displays. Avoid powering everything from your simulator PC’s USB port—it can cause data glitches and voltage drops. Always use shielded cables for long runs to reduce electromagnetic interference from other cockpit electronics (e.g., servo motors or backlight inverters).

Hardware Setup and Assembly

Before writing any code, you need to physically connect the display to the microcontroller. The exact wiring depends on your display’s interface (I²C, SPI, or parallel). Consult the manufacturer’s datasheet, but here are general guidelines.

Wiring Basics

For a typical I²C OLED (0.96″ SSD1306):

  • VCC → 5V (or 3.3V if your display supports it)
  • GND → GND
  • SCL (clock) → microcontroller SCL pin (A5 on Arduino Uno, D22 on ESP32)
  • SDA (data) → microcontroller SDA pin (A4 on Arduino Uno, D21 on ESP32)

For SPI TFT displays (e.g., ILI9341), you will need more pins: CS, DC, MOSI, MISO, SCK, and an optional backlight control. Many libraries assume a specific pinout; follow the library’s wiring diagram carefully.

If you are using an ESP32, take advantage of its second SPI bus to free up pins for other functions. A breadboard is fine for testing, but once you finalize the design, solder the connections onto a protoboard or use a screw‑terminal shield.

Mounting the Display

The display should sit at a comfortable viewing angle, ideally just below your line of sight. In a fixed‑base cockpit, you can cut a hole in the panel and secure the display with standoffs or a 3D‑printed bezel. For a more polished look, design a bezel that matches the rest of your instrument panel. Many builders use a laser‑cut acrylic overlay with a black matte finish to reduce glare. Ensure good airflow behind the display—some TFTs generate noticeable heat when the backlight is on full.

Software Integration

This is where your display comes alive. The microcontroller must request data from the flight simulator in real time and render it on the screen. The method depends on the simulator you use.

Choosing a Data Protocol

Most modern simulators support one or more external data interfaces:

  • SimConnect (Microsoft Flight Simulator 2020/2024, FSX, Prepar3D): A powerful SDK that provides hundreds of simulation variables. You write a client application (often in C++ or C#) that connects via TCP or named pipes. For microcontrollers, you typically run a bridge software on the PC that forwards data over serial or UDP.
  • FSUIPC (Prepar3D, FSX): A popular payware add‑on that exposes data through a memory‑mapped interface. Widely used for external instruments. The free version (FSUIPC4/5) works for most needs.
  • X‑Plane UDP: X‑Plane 11 and 12 send data via UDP datagrams to any IP/port. The format is well documented; you can parse it directly on an ESP32 with Wi‑Fi. This is one of the simplest wireless integrations.
  • DCS‑BIOS (DCS World): A streaming protocol used by the DCS community. Data packets are sent over serial or UDP. Libraries exist for Arduino and ESP32.

If you are using Microsoft Flight Simulator 2020, the SimConnect bridge is the most common route. Several community projects (like ArduSimConnect) provide Arduino libraries that simplify the connection. For X‑Plane, you can use the built‑in UDP output without any extra software.

Reading Data from the Simulator

Once you have chosen a protocol, you need to write or configure the data fetching logic. In SimConnect, you define a “SimObject” and request specific variables (e.g., “PLANE ALTITUDE”, “AIRSPEED INDICATED”). The simulator sends updates at a frequency you set (typically 10–60 Hz). For X‑Plane, you configure which data refs to output and at what rate in the “Data Output” menu, then your microcontroller parses the incoming bytes.

On the microcontroller side, you will usually read from a serial port (USB) or a UDP socket. To avoid stalling the display loop, use non‑blocking reads. Many libraries handle this automatically, but if you write your own parser, add a timeout so the display still updates with a “No Data” message if the connection drops.

Displaying Data on the Screen

After you have the raw numbers, you need to render them. The most popular graphics libraries are:

  • Adafruit GFX + SSD1306/ILI9341: Works with many Arduino‑compatible displays. Easy to use, with basic shapes and text.
  • U8g2: Excellent for monochrome displays. Supports a huge range of screens and fonts.
  • LVGL (LittlevGL): A sophisticated graphics framework that runs on ESP32 and Raspberry Pi. It supports multi‑page layouts, animations, and touch input. Overkill for a simple numeric display, but great for a full glass cockpit.

Start simple: display three or four numeric values. As you gain confidence, add visual gauges—tape scales for airspeed and altitude, a compass arc for heading, or even a simple artificial horizon using filled rectangles.

Sample Code and Implementation

Below is a more complete example for an ESP32 driving an I²C OLED display, reading altitude from X‑Plane via UDP. The code receives X‑Plane’s sim/cockpit2/gauges/indicators/altitude_ft_pilot data ref and displays it.

#include <WiFi.h>
#include <WiFiUdp.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>

// Wi‑Fi credentials
const char* ssid = "YourSSID";
const char* password = "YourPassword";

// X‑Plane UDP settings
const int localPort = 49000;   // port to listen on
const int xplanePort = 49000;  // X‑Plane output port

WiFiUDP udp;
Adafruit_SSD1306 display(128, 64, &Wire, -1);

// Buffer for incoming packet
char packetBuffer[1024];

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi connected");
  udp.begin(localPort);

  // Initialize display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("SSD1306 allocation failed");
    for(;;);
  }
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("ALT: ...");
  display.display();
}

void loop() {
  int packetSize = udp.parsePacket();
  if (packetSize) {
    int len = udp.read(packetBuffer, 1024);
    if (len > 0) packetBuffer[len] = 0;

    // Here you would parse the X‑Plane UDP packet.
    // For simplicity, assume we extract a float altitude “alt”.
    // (Real X‑Plane UDP parsing requires handling the BUNCH format.)
    float alt = 1234.5; // placeholder

    display.clearDisplay();
    display.setCursor(0,0);
    display.print("ALT: ");
    display.print(alt, 0);
    display.println(" ft");
    display.display();
  }
  delay(50);
}

Real implementation requires a proper X‑Plane UDP decoder. For a SimConnect approach using an Arduino, you would run a bridge on the PC (like ArduSimConnect) that sends formatted data over serial.

Always include error handling: if no data arrives for two seconds, display “NO DATA” in red (if using a color display) or blinking text. This helps during troubleshooting.

Customization and Advanced Features

Once your basic display works, you can tailor it to your exact needs.

Layout Design

Think about what information is most important during flight. Typically, airspeed, altitude, and heading are shown in large, central positions. Secondary data (vertical speed, G‑force, fuel flow) can be smaller. Use different font sizes or colors to create a hierarchy. If your display supports bitmaps, you can draw simple instrument faces using polygons.

Adding Multiple Displays

One microcontroller can often drive two or more displays, especially with I²C multiplexers or separate SPI chip selects. Use one display for primary flight data and another for navigation information (course, nav frequencies). For a Pi, you can attach several HDMI or DSI screens directly.

Data Logging and Alerts

Add an SD card slot to the microcontroller and log data to a CSV file for post‑flight analysis. You can also set soft alerts: for example, flash the display when the altitude exceeds a user‑defined limit or when the fuel is low. These alerts make the display not just a readout but an active co‑pilot.

Testing and Troubleshooting

Even a well‑designed display can suffer from glitches. Here are common issues and their fixes.

Data Lag or Stuttering

If the numbers update slowly or stutter, lower the data update rate in the simulator or use a faster baud rate (115200 or higher for serial). On a wireless connection, ensure your router is on a clean Wi‑Fi channel. For wired connections, a short USB cable (under 3 feet) with ferrite beads helps.

Flickering Display

Flickering is often caused by the display being updated too many times per second. Insert a delay(30) or use an interval timer (e.g., refresh every 50 ms). On I²C OLEDs, ensure pull‑up resistors (4.7kΩ) are present on SCL and SDA lines. For SPI TFTs, check that the backlight pin is not unstable.

Power Issues

If the microcontroller resets when the display lights up, your power supply cannot handle the inrush current. Use a larger capacitor (100 µF) across the power rails near the display connector. If using a long USB cable, power the display directly from a separate 5V supply.

Additional Resources

Building a custom flight data display is a project that grows with your skills. Start with a simple numeric readout on an OLED, then gradually add color, gauges, and wireless capability. The result is a cockpit that feels truly yours—responsive, informative, and built with your own hands. With the right components and a methodical approach, you can achieve a level of integration that matches or exceeds commercial instruments, all while deepening your understanding of both electronics and flight simulation technology.