The LX FLARM LED Display Pro is a small screen with a ring of coloured LEDs around it, mounted where you can see it without looking at it. That is the whole idea: the ring is read in peripheral vision while your eyes stay outside, and the screen is there for the moment you can afford to glance down. This article explains every colour, every screen and every fault message, so that the first time you see a steady red ring you already know what it means.
The device ships as a bare unit. No mounting material, no adhesive, no cable — plan for those before it arrives.
The cable you have to source
The right cable depends entirely on which FLARM device you are connecting to.
Standard FLARM with an RJ45 IGC port
Most current FLARM devices use a standard RJ45 connector for their data port. Buy a straight-through (1:1) RJ45 patch cable of a suitable length. Do not use a crossover cable — it will not work.
Older FLARM with an RJ11 port
Some older units use the smaller RJ11 connector. Buy a ready-made RJ45-to-RJ11 adapter cable, or build one against the pinout below, checking that power, ground, TX and RX land on the correct RJ45 pins at the display end.
NAVIA Traffic, FLARM Fusion and Air Avionics AT-1
The manual's one worked harness is for the NAVIA Traffic's J200 connector: pin 1 V_OUT to RJ45 pins 1 and 2, pin 2 GND to pins 7 and 8, pin 3 TX to pin 5, pin 4 RX to pin 6. Verify the voltage on V_OUT is within 10–18 V DC before you connect the display. FLARM Fusion and the Air Avionics AT-1 are also named as units with their own connectors — follow their pinouts the same way.
Anything with a proprietary connector
Some traffic systems use their own connectors and need a custom harness. Identify the power output, ground, RS232 TX and RS232 RX pins on your device's connector and wire them to the matching RJ45 pins. Where the manufacturer publishes a connector document, follow it rather than guessing from a multimeter.
Wiring and mounting
| Pin | Function | Notes |
|---|---|---|
| 1 | +12 V power | Main power input, internally fused |
| 2 | +12 V power | Main power input, internally fused |
| 3, 4 | — | Not connected |
| 5 | Data In | To the FLARM data output (TX) |
| 6 | Data Out | To the FLARM data input (RX) |
| 7 | Ground | Power and signal ground |
| 8 | Ground | Power and signal ground |
A single cable carries both power and data. The socket accepts both 8-pin RJ45 and 6-pin RJ12 plugs. Because pins 1 and 2 are both power and pins 7 and 8 are both ground, an RJ12 plug still lands on a power pin, a ground pin, Data In and Data Out — so a standard 6-conductor straight-through FLARM cable works unmodified.
Supply voltage is 10–18 V DC, 12 V nominal. There is an internal converter, but a 5 V or 3.3 V supply will not run the unit, and an out-of-range supply will damage it.
For mounting: the unit is 61 mm × 22 mm × 22 mm including the connector and weighs about 40 g, so high-strength double-sided tape is all it needs. Clean and degrease the surface first. The glare shield, the panel bezel and the canopy rail all work. Before the tape goes down for good, sit in your normal flying position and confirm the whole LED ring is visible and not clipped by the panel surround — a ring you can only half see is worse than no ring. Route the cable with a gentle bend radius, and nowhere near the controls or the canopy mechanism.
The start-up sequence
Step 1, logo screen, 0 to 6 seconds. The logo appears with a short beep while the LED ring runs a self-test: red for the first second, green for the second, blue for the third, then dark. That cycle is your proof that every LED still works. Below the logo the display steps through the device name, then the serial number, then the software and hardware version.
Step 2, connecting. The screen shows Connecting… with a baud-rate counter and animated dots while the unit cycles through the supported speeds — 9600, 19200, 38400, 57600 and 115200 bps — looking for the one your FLARM uses. Do not press the button during this phase — just wait.
Step 3, ready. The screen clears and the device is in normal flight operation. If the counter keeps cycling and never locks, the fault is upstream: the FLARM is not powered, the cable is not fully seated at both ends, or the FLARM is not configured to output data on its IGC/NMEA port.
The LED ring
This is the part worth learning by heart. The ring is designed to be read without turning your head.
| Colour and pattern | Meaning |
|---|---|
| Off | Starting up, or the settings menu is open |
| Blue, pulsing | Waiting for a GPS fix, or no FLARM connection yet |
| Green | Traffic nearby, no immediate threat |
| Yellow | A specific aircraft is relevant — monitor it |
| Red, steady | Collision warning — look out and manoeuvre |
| Red, blinking | Obstacle warning — a fixed hazard ahead |
When a warning is active, the lit arc also points at the threat. A cluster of LEDs at the two o'clock position means traffic ahead and to your right. Colour tells you how urgent; position tells you where to look. Nothing else on the device matters as much as these two facts.
Idle screens, when the sky is clear
With no threat present the display shows one of three idle screens, chosen in the settings menu.
- Clock — a large time display taken from the FLARM GPS receiver and updated every second. Accurate, and it never needs setting; the time-zone offset is adjustable, or leave it at UTC.
- Nearest traffic — the closest aircraft your FLARM is tracking even when it is not a declared threat, with vertical separation (
Alt, positive above you), horizontal distance (Dist) and a rotating arrow pointing at it. - Own ship — your ground speed (
GS) and track over the ground (TRK), live from the FLARM GPS.
Warning screens
The moment your FLARM declares a threat at any alarm level, the display switches to the screen that suits the geometry. No pilot action is required, and there is nothing to press.
Standard warning screen. When it appears: for the majority of encounters — aircraft crossing, converging from the side, or overtaking. Down the left is an elevation strip: sky blue at the top, ground brown at the bottom, with a white marker showing whether the conflict is above or below your horizon. Marker high, look up. Marker low, look down. On the right are the relative altitude and horizontal distance. Combine the strip with the LED arc and you have a three-dimensional vector: that direction, at that height.
Head-on warning screen. When it appears: only for a high-priority threat within 45° of your nose and flying towards you. In a head-on encounter closing speeds can exceed 300 km/h and there is no time to read numbers, so this screen has none. Instead it draws a synthetic horizon and places an aircraft symbol at the exact angular position in your forward field of view where the real aircraft will appear. Symbol high and right: look up and right through the canopy. Manoeuvre away from the symbol. As the alarm level rises the symbol blinks faster and the orange circle around it grows, so urgency arrives without a single digit being read.
Obstacle warning screen. When it appears: the FLARM obstacle database contains a known fixed hazard ahead — a radio mast, a cable car, a high-tension line. The screen turns red and shows the obstacle type, the distance and the obstacle's altitude relative to yours, while the LED ring blinks red continuously.
Restricted airspace warning screen. When it appears: you are approaching or entering airspace your FLARM has flagged as restricted, prohibited or controlled. It shows the airspace type, the distance to the boundary and that boundary's altitude relative to you. What those classifications actually mean is covered in the academy article on airspace.
Audio warnings
An integrated buzzer escalates with the threat, so the pattern alone tells you how much time you have.
| Sound | Meaning |
|---|---|
| Slow single beep, about 1 per second | Traffic nearby, not yet a threat |
| Faster double beep, about 2 per second | Converging aircraft — look outside |
| Rapid beeping, about 4 per second | Immediate collision risk — act now |
| Distinct repeating pattern | Obstacle or airspace warning |
The settings menu
Press and hold the single button for about 1.5 seconds from any flight screen. The menu opens and the LED ring switches off — which is why a dark ring in flight means somebody left the menu open.
| Action | Method |
|---|---|
| Move to the next item | Short tap |
| Select an item to change | Long press — the value turns orange |
| Cycle through options | Short tap while the value is orange |
| Confirm | Long press while orange — the value returns to white |
| Leave the menu | Scroll to Exit and long press |
The settings themselves are units for altitude, distance, speed and vario; the idle screen; the time-zone offset; a factory Reset; and Demo Mode.
Demo Modegenerates simulated traffic for ground testing. With it on, the display shows invented threats and will not react to real FLARM traffic. Turn it off before every flight.
When something is wrong
| Symptom | Cause | Fix |
|---|---|---|
NO GPS on screen | Your FLARM has lost its satellite fix | Traffic is still detected and warnings may still be issued, but direction cannot be computed and range is unreliable. Normally recovers in 1–2 minutes with a clear sky view. |
NO FLARM on screen | Lost communication with the FLARM unit | Check the RJ45 cable is fully seated at both ends and the FLARM is powered. |
Stuck on Connecting…, counter cycling | FLARM off, cable loose, or no data on the IGC/NMEA port | Confirm FLARM power, reseat both ends, enable NMEA output on that port. |
| Blank display, no logo, no beep | No power, or a supply outside 10–18 V DC | Check the supply at the plug. Never feed it 5 V. |
| Ring stays dark in flight | Settings menu was left open | Scroll to Exit and long press. |
| Threats appear that are not there | Demo Mode left on | Turn it off in the settings menu. |
| Nothing works with a new cable | Crossover cable fitted | Replace with straight-through (1:1). |
| Display permanently damaged | Left in direct or focused sunlight while parked | Not recoverable, and not covered by warranty. Cover the panel when parked. |
Do not leave the device exposed to direct sunlight in a parked aircraft: a canopy concentrates sunlight like a lens and the display will not survive it. There is also a small game hidden in the firmware, reachable only during the logo screen, which is either a pleasant surprise at the holding point or an argument for keeping your hands off the button — your call.
Where to go next
- Firmware and documentation: the FLARM LED Display Pro download page.
- The reasoning behind the alarm levels: how FLARM works, and the wider traffic picture in transponders and ADS-B.
- Hardware: FLARM LED Display Pro.
- Anything that does not match this article: your dealer first, then LX support.