Color lighting, live battery indication, field calibration, and a dedicated battery-checker mode—all controlled with two buttons.
The LEDs perform a white sweep, then show the battery level.
Red means low, amber is the middle range, and green is near full.
Tap Button 1 or Button 2. Leave the color selected for one second and it is remembered after power is removed.
The seven blocks above represent mirrored LED pairs. Press and hold the buttons at the top just like the physical product.
Seven dual-sided positions fill from red through amber to green. The upper end uses your calibrated full voltage.
The bar is intentionally subdued for handling. A reading below the calibrated full level is followed by three bright red attention flashes.
| Voltage | Behavior |
|---|---|
| Below 3.40 V for 10 s | Normal lighting dims and shows a low-battery warning. |
| Below 2.80 V briefly | The LEDs spend most of their time off and briefly warn in red. |
The buttons lock after 10 seconds without activity so vibration or accidental contact cannot change your color during a flight.
While locked, presses and long holds are ignored. A rejected press briefly blacks out one LED pair so you can see that the controls are locked; battery monitoring continues normally.
Connect the battery ahead of time without leaving the main LEDs running. Armed standby remembers your color; waking shows the battery level, then gently restores the color over one second.
In standby, external LEDs stay off and one mirrored LED pair gives a very dim, slow heartbeat. This keeps the chosen color identifiable while greatly reducing LED power.
Keep holding instead of releasing to use the normal 5-second calibration or 10-second reset.
Different batteries and setups can read slightly differently. Calibrating at full charge makes the startup bar and full-battery indication match your own setup.
Two short green blinks confirm that the present voltage is now treated as full.
Three blinks confirm restoration of the default 4.17 V full level.
Important: after 10 idle seconds, unlock the buttons first. Calibrate only with a properly charged battery. Accepted calibration range: 3.5–5.0 V.
Use the board as a persistent battery monitor while the same battery powers other equipment. The display stays economical during normal use but becomes increasingly difficult to miss when the battery is nearly empty.
The live battery bar stays very dim to save power. Release the entry button first; a new hold then makes the bar gradually brighter for viewing in sunlight. Release to return immediately to the power-saving level.
Below 3.45 V the bar dims further. At 3.40 V it changes to a red blink that gradually grows to full brightness over two minutes.
✓ Last selected color
✓ Calibrated full voltage
✗ Temporary operating modes after power-off
Buttons do nothing: use the three-click unlock.
Battery bar seems wrong: recalibrate at full charge.
Checker mode did not start: hold the button from power-on through the complete startup display and for two more seconds.
Need the same lighting on a larger build? The onboard pattern can continue along an external addressable LED chain without changing how the two buttons work.
The data output supports up to 64 LEDs. The 14 onboard LEDs remain the main 7+7 mirrored light; positions 15–64 repeat that complete onboard pattern.
Power separately: external LEDs need a correctly sized supply and a shared ground. The PCB firmware supplies their data signal, not their power.
This board is intended to run from a single-cell (1S) LiPo. In typical racing use the extra current draw from the LEDs is imperceptible and effectively negligible compared to the motors. Example: a 6S 1500 mAh race pack emptied in ≈90 s represents an average flight power around 1.5 kW, while the LEDs consume ≈4 W at full white (≈0.25% of flight power).
You can attach external addressable LEDs to the three solder pads (data, +V, GND). These external LEDs run from the same 1S voltage as the onboard LEDs — no separate supply is required for small chains.
All features are accessible from the primary button; the second button on some PCBs may be disconnected due to manual hardware changes. The button lock prevents accidental changes caused by vibration — unlock with three quick clicks.
Use this as your pre-flight color card: find the channel assigned to you and select the color beside it. The list is ordered by VTX frequency and follows Betaflight's frequency colors wherever possible. Less commonly used Raceband channels are included in the last column.
| Channel | Frequency | Select | Other Raceband |
|---|---|---|---|
| L6 | 5547 MHz | ORANGE | R3 · 5732 MHz |
| L7 | 5584 MHz | CYAN | — |
| R1 | 5658 MHz | WHITE | — |
| R2 | 5695 MHz | RED | — |
| F2 | 5760 MHz | YELLOW | R4 · 5769 MHz |
| F4 | 5800 MHz | GREEN | R5 · 5806 MHz |
| R7 | 5880 MHz | BLUE | R6 · 5843 MHz |
| R8 | 5917 MHz | MAGENTA | — |
Why L6 and L7 differ: Betaflight normally places L6, L7, and R1 in the same white frequency range. Orange and cyan intentionally separate the two low-band channels, while R1 keeps white. Blue and magenta are the closest available matches for Betaflight's dark violet and deep pink.
Programming uses a 1.27 mm pogo-pin connector. Four pins (SWCLK, SWDIO, GND, VCC) are the minimum for SWD programming; a 7-pin connector is useful if you want reset and UART (RX/TX) for features like a future UART bootloader or Betaflight passthrough.
Common tools (J-Link OB, ST-Link) work for flashing. A low-cost J-Link OB V8 with USB-C has been used successfully for testing.