Choose displays and instruments for your cockpit

Specify the information on paper first

For each instrument, write down the value name, unit, useful minimum and maximum, and viewing distance. Do you need a quickly readable number, a pointer showing a trend or a menu offering several functions? A polished graphic does not automatically serve all these purposes equally well.

Draw the longest label and largest number at actual size. From your seat, check whether signs, decimal points and units remain visible. Include an unmistakable indication for unavailable data. A frozen number can look entirely credible after its connection has stopped updating.

Choose the format to suit the job

A PC monitor receives a video signal; a small microcontroller display receives commands or image data through its designated interface. These are different paths. If you want to start without additional electronics, investigate using existing screens for separate instruments.

Check the whole connection chain

Record the exact module, controller and revision. “128×64 OLED” does not uniquely identify its interface. Compare supply requirements, permitted logic levels, connector assignments, bus type and supported library. A voltage regulator on the board does not establish higher-voltage tolerance on every signal.

For I2C, plan the address, required pull-ups and other bus participants. Two devices with the same fixed address need an appropriate solution; putting them in parallel does not remove the conflict. SPI also involves device-selection and sometimes other control lines. Do not infer an address or pin list simply from a module’s appearance.

A concrete check for space and memory

On a character LCD, −123.4 requires six character cells: a minus sign, three digits, a decimal point and a fractional digit. The unit needs more space. On a seven-segment display, the decimal point is often an extra segment attached to a digit and does not consume another digit position. Check the actual module’s digit count, minus-sign support and available points. Choose range and formatting before buying; silent truncation is not useful error handling.

A complete monochrome frame buffer with 128×64 pixels at one bit per pixel requires 128 × 64 / 8 = 1,024 bytes. Two require 2,048 bytes before variables, libraries and other data. This is a memory calculation, not a claim that every library uses a full frame buffer. Check the actual implementation and the controller’s available memory.

Check readability before making the final faceplate

Try a sample at the intended angle, behind the planned window and at the real viewing distance. A display that looks good on the workbench may become difficult to read behind a reflective cover. Check day and night conditions, minimum brightness and the edges. On a character LCD, working backlighting and properly visible characters are separate checks.

Measure the board outline, visible area, mounting holes and connector overhang separately. Allow for cable bends, access to contrast adjustment and eventual replacement. A small printed or machined trial frame is useful before making the full panel. Share that sample in the forum when discussing 3D printing, CNC or LightBurn work.

For a mechanical pointer, distinguish a positional servo from a continuous-rotation servo: the latter does not specify an unambiguous pointer position without additional feedback. A stepper moves in steps and needs suitable drive electronics. Match driver, supply and mechanical coupling to the actual motor instead of copying another build’s photograph. Include the motor load in your power budget.

Define how the pointer obtains a known reference or zero after every start. A stored software position alone does not establish its real position. Limit travel to the usable mechanical range and avoid accidentally driving into stops. Then check three known targets at the beginning, middle and end of the scale for correct direction and indication. Repeat from both movement directions and after restarting. This is a calibration plan, not a universal motor pinout.

A plausible number may still be the wrong value

Separate raw data, conversion and presentation. Record the source unit and display unit and convert only once. Choose rounding, leading zeros and decimal notation deliberately. Out-of-range or missing data needs a defined display state; do not silently present the last valid number as current.

The update behaviour should suit the instrument. A moving scale and an occasionally changed setpoint have different needs. Begin with a stable, manageable update pattern and observe whether other functions become less responsive. Slow display operations must not unexpectedly block your inputs. Suitable rates depend on hardware, library and data source.

Verify hardware and simulator support separately

A manufacturer’s demo proves that the local display works. It does not prove a connection to Cockpit Suite or your simulator. Next, check the intended data path and output support. Cockpit Suite provides a common software environment for several simulators; that does not automatically make every display compatible.

Falcon BMS and DCS F-16C are available; War Thunder, ETS2 and ATS are in beta, and LS25 is in development. Available Cockpit Suite adapters are not promised for MSFS or X-Plane. Support for DCS F-16C is not a claim of support for every DCS aircraft. Base your build on functions confirmed for the particular project.

Move from a fixed test pattern to an instrument

1. Record the module and documentation, then check power and connections with power disconnected.
2. Use a matching local example with fixed characters or a test pattern. Check every position and required symbol.
3. Display controlled minimum, middle and maximum values. Include negative values, overflow and unavailable data.
4. Only then connect a confirmed source and compare the display with the simulator in controlled conditions.
5. Check restarting, reconnection and profile changes. Save layout, firmware and library versions with the results.

With multiple displays, establish one reliable unit first. Add the second, then reassess the shared supply and bus.

Investigate the layer that actually failed

Backlight only: check supply, contrast, initialisation and communication separately. Wrong characters: investigate controller, library, character set and bus. Correct characters but wrong numbers: inspect units and mapping. Shifted or truncated values: check field width and formatting. A correct local test image with wrong simulator data is no reason to rewire randomly.

The sample is ready when it is readable from your seat, handles boundary cases clearly and works the same way after restarting. Keep a photo with the module name, connection diagram and software versions. Those details help the forum much more than “display not working”. We aim to respond on the same day where possible. Documented experiences from Europe and the wider community help us improve further combinations with evidence.

Continue your project