Display interface PCBThe GliderScore Display Interface is an embedded processor-based board designed to be directly connected to a serial port (or USB-to-serial converter) on a computer that is running the popular GliderScore scoring application for RC soaring contesting. The Display Interface accepts commands from GliderScore and displays competition event time in minutes:seconds format on four outdoor LED display digits. It also supports a Round-Group display: boards can either periodically interleave the current Round and Group numbers with time counts or a board can be configured to always display just Round-Group information. Very flexible!

The Display Interface board supports a wide variety of common-anode LED display boards that the user purchases separately depending on their site and visibility needs. The GliderScore Display Interface product is carefully designed for minimum power consumption in battery-operated environments but works equally well in AC-powered environments.


A typical GliderScore Display Interface system is comprised of the following components:

1.  The processor-based Display Interface board,
2.  Four 7-segment LED display boards, and
3.  A 12v battery or DC power supply.


Display Interface board

The low power interface board is designed to run on 12v that can come from either a battery or an AC-powered module. The external LED displays are connected to the board by short 9-wire cables to each digit. Setup options are provided via plug jumpers on the board.

LED board 9inchExternal LED Displays

The LED displays will need to be large enough to enable outdoor viewing from a distance. As a basic guideline 9" standard brightness 7-segment LED display boards are visible 350-400 feet (120mtrs) away. Larger and ultra bright LED displays can be seen from greater distances if needed.

Selected Product Features

  • Converts GliderScore timer display commands into an external LED interval timer display
  • Supports GliderScore's Extended Protocol for display of Round and Group information in addition to timer values
  • Runs in AC-powered and battery-powered environments
  • Supports a wide variety of commercially available LED display boards
  • Non-multiplexed LED drivers for maximum possible display brightness
  • Low power processor-based interface board
  • On-board discrete LED status indicators:
    - Serial command received
    - Command error detected (serial command overrun, etc )
  • Selectable serial baud rate: 9600 or 19200 baud
  • Selectable power-saving zero-blanking option (intended for use at battery-operated sites)
  • Comprehensive User Guide covers interface board and LED display installation tips and techniques

Display Interface Board Specifications

  • Board dimensions: 119.7 x 98.5mm (4.7" x 3.9"). Height of components on board 18mm (0.7") max.
  • Input power requirements: 7-16VDC @ 50mA max (not including external LED display current requirements). Typical current load = 25mA.
  • Operating Temperature: -10 to 65 degrees C (15 to 150 degrees F)
  • GliderScore command formats supported:
    Standard "Embedded-Ability" format: "Ammss+CR"
    ASCII character string "Ammss \r" (the letter A, the minutes digits, the seconds digits, the
    ASCII character for Carriage Return).
    Extended Protocol format: "R99G99TmmssAA+CR"
    R99 - 99 is the round number.
    G99 - 99 is the group number.
    Tmmss, there "mm" is 2 digits for minutes and "ss" is 2 digits for seconds.
    AA - Two character code for timer state: PT prep time, WT working time, LT landing time, ST sleep time, DT display time-of-day.
    CR - ASCII Carriage Return.
  • Serial port configuration: Selectable baud rate = 9600, 19200. Always 8 data bits, 1 stop bit, no parity. Only the receive data line is monitored, all other serial port signals are ignored.
  • Serial port cabling length: Max. recommended for shielded or unshielded non-twisted pair cable: 15 meters (49 ft) @ 9600 baud, 7.6 meters (25 ft) @ 19200 baud. Max. recommended for twisted-pair cable (e.g. CAT5e): 60 meters (197ft) @ 9600 baud, 30 meters (99ft) @ 19200 baud. RS-232 range extenders (wired or wireless) can be used for longer runs: we use p/n GC-ATC-863-S1 wireless RS-232 units from GridConnect.
  • External LED display current limits: 150mA maximum current per display segment (each 7-segment display digit has 7 segments plus the decimal point).
  • External LED display voltage supply limits: 50V absolute maximum, 24v max recommended.
  • External LED display configuration supported: Common-anode only (open drain drivers electrically connect to ground to illuminate a digit segment).
  • Input terminals: RXD IN+/- (transient and over-voltage protected), V+/GND (reverse polarity protected).
  • Output terminals: 10's Minutes (9 wires), 1's Minutes (9 wires), 10's Seconds (9 wires), 1's Seconds (9 wires).

LED Display Sources

The LED display board sellers listed on this page offer products that should be fully compatible with the GliderScore Display Interface. However, E-A has not tested all the listed LED displays and thus cannot guarantee they will work perfectly in your particular site's application. Some points to keep in mind:

  1. Common-anode only. Only displays that can be configured as common-anode are usable with the display interface.
  2. Per-segment current. Be sure to verify the per-segment current that a given LED display requires. The display interface can drive up to 150mA of current per segment.
  3. Standard/Normal versus Ultra/Super Bright.  While the terminology for brightness is not used consistently generally speaking normal LED displays (like the MXA037) are very usable in outdoor lighting conditions and work best with a red acrylic contrast enhancer sheet.  Even better with a top shade to keep the sun's direct rays off the displays. Ultra bright displays can take the sun's direct rays, again with a contrast enhancer sheet, but at a cost of a narrower viewing angle. If you want to build only a single display then using standard (non-ultrabright) LED boards is more versatile.

If you would like to suggest additions and updates to this page let us know.

Date last updated: Jan 3, 2020

General note: The 9" MXA037 LED board is by far the best overall "value" (display size versus cost) that I have found.

QKits in Ontario Canada.  They offer many of the MXA series of LED displays. Their price for the 9" MXA037 is the cheapest we have found: $27 USD + shipping. The ultrabright 9" MXA004 goes for $40 USD.  Their 10" MXA079 is the cheapest we have found: $60 USD + ship. For only $10 more you can get the 10" ultra bright version MXA078.

Kitstop in Australia. This seller carries a wide range of LED displays listed on this page. The 10" red MXA079 and 9" MXA037 are great choices for the display interface. Kitstop's prices (e.g. MXA037) are not the cheapest but they carry a good stock.


GliderScore Display Interface User Guide-Table of Contents (PDF)
Note: the full user guide will be emailed to you immediately following your order confirmation. Don't hesitate to contact us if you have specific questions.



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