ELRS binding guide

Bind in under 60 seconds.

Works for ExpressLRS firmware 3.x and 4.x. Pick your APEXFPV drone below — exact pinout, default bind phrase, and edge cases included.

⏱ Target time: 45–60 sec end-to-end
RX Built-in ELRS 2.4 GHz FC F411 AIO UART UART2 RX/TX (CRSF 420 000) Default bind phrase none — physical button

  1. Power radio first 0:00 → 0:05

    Radio (TX16S, Boxer, Pocket, etc.) ON. Open Model Settings → Internal RF → Mode = ExpressLRS → Output power 100 mW (bench bind).

  2. Set your bind phrase 0:05 → 0:15

    In your radio TX module web UI (elrs.local via Wi-Fi) or Tools → ExpressLRS on EdgeTX: set a unique bind phrase (e.g. my-foldape-2026). Save + reboot module.

    Why? Bind phrase is shared secret — same phrase on TX + RX = auto-bind, no physical button.

  3. Flash bind phrase to RX 0:15 → 0:35

    FoldApe LR built-in RX is pre-flashed with default ELRS firmware. To set your phrase, plug FC USB → open ExpressLRS Configurator → Target BetaFPV / HappyModel 2.4 GHz RX → enter your bind phrase → Build & Flash via WiFi or BetaflightPassthrough.

    Configurator → Build → "Flash via Betaflight Passthrough" → confirm

  4. Verify link in Betaflight 0:35 → 0:55

    Power drone (no props). Open Betaflight → Receiver tab. Move sticks — channels move. Check Status tab → RSSI ≥ −80 dBm, LQ ≥ 90% on bench.

  5. Save model + arm test 0:55 → 1:00

    Set arm switch in radio (default AUX1, 2-pos, 1800µs = ARM). Throttle low. Arm switch ON → motors beep → DISARM immediately. Done.

RX Built-in ELRS 2.4 GHz FC F411 AIO + 30A 4-in-1 ESC UART UART2 RX/TX (CRSF 420 000) VTX option Analog or Digital

  1. Radio in ExpressLRS mode 0:00 → 0:10

    Same as FoldApe — Internal RF = ExpressLRS, set output power 100 mW for bench bind. EdgeTX recommended (v2.10+).

  2. Set + flash bind phrase 0:10 → 0:35

    In ExpressLRS Configurator: Target HappyModel EP 2.4 GHz RX (or DarwinFPV variant). Enter bind phrase. Flash via WiFi (RX broadcasts ExpressLRS RX SSID after triple power-cycle) or Betaflight Passthrough.

    Triple power-cycle method — power drone, wait LED red solid, unplug; repeat 2 more times. RX enters Wi-Fi mode after 3rd cycle.

  3. Verify link 0:35 → 0:50

    Betaflight Receiver tab → channels move. Status → RSSI / LQ check. If not bound: confirm bind phrase exact match (case-sensitive). Reboot drone.

  4. Arm test 0:50 → 1:00

    Props OFF. Arm switch ON → motors beep → DISARM. Confirm failsafe behavior in Failsafe tab → Drop (freestyle preset).

RX TBS Nano ELRS (or PNP) FC SpeedyBee F405 V3 + STM32F722 UART UART1 RX/TX (CRSF 420 000) App SpeedyBee BLE

  1. Radio ExpressLRS + bind phrase 0:00 → 0:15

    Radio Internal RF = ExpressLRS. Set bind phrase via TX module web UI or EdgeTX Tools. TBS Nano comes pre-flashed with HappyModel firmware EP_2400_RX V3.01 compatible ELRS 3.x.

  2. Flash bind phrase to TBS Nano 0:15 → 0:40

    Plug drone USB. SpeedyBee app → connect via BLE OR Configurator → Target HappyModel EP RX 2.4 GHz. Enter same bind phrase as TX. Flash via Betaflight Passthrough — fastest path.

    SpeedyBee BLE shortcut — pair phone via BLE → ExpressLRS section → set bind phrase → no USB cable needed.

  3. Verify in Betaflight or SpeedyBee app 0:40 → 0:55

    Receiver tab → channels move. RSSI ≥ −80 dBm bench. TBS Nano LOS range ~1 km — verify link before flying long-range.

  4. Save model + arm test 0:55 → 1:00

    Props OFF. Arm switch ON → motors beep — listen for clean 6S idle, no de-sync ticks (BL32 50 A ESC + 2306.5 1800 KV). DISARM. Done.

Troubleshooting

Drone won't bind — solid red LED on RX
Bind phrase mismatch (case-sensitive) OR TX module power off OR firmware version mismatch (TX 3.5.x cannot bind to RX 4.x). Match major versions.
Bound but channels don't move in Betaflight
UART not enabled. CLI: set serialrx_provider = CRSF, set serial 1 64 (UART2 = serial 1). Save + reboot.
Low LQ / disconnects on bench
RX antennas crossed or against carbon. Re-route in V or T config, away from VTX antenna. SMA torqued.
RX won't enter WiFi mode for re-flash
Triple power-cycle: power, wait red LED solid (~3 sec), unplug. Repeat 3× total. SSID ExpressLRS RX appears, password expresslrs, captive portal at 10.0.0.1.
Failsafe doesn't trigger when radio off
Betaflight Failsafe tab → Stage 2 = Drop (freestyle) or RTH (long-range with GPS). Verify set failsafe_throttle = 1000. Test on bench before flight.