Happymodel ExpressLRS F4 5A 5-in-1 AIO FC w/ Built-in 2.4GHz Rx 2G4

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  • $57.99

About this product

The Happymodel ExpressLRS F4 is the world's first AIO 5-in-1 whoop flight controller with a built-in high-performance 2.4GHz ELRS receiver. This F4 flight controller has a built-in 5A ESC, 5.8GHz VTX, and OSD. This AIO is made for 1S long-range and tiny whoops.

This FC integrates an SPI-controlled 2.4GHz ExpressLRS receiver, Dshot protocol 4-in-1 ESC, 5.8GHz 40ch video transmitter, and Betaflight OSD. Ultra-small size and ultra-stable remote control range can improve the range of the original SPI receiver. The 2.4GHz ExpressLRS receiver is equipped with the SX1280 radio frequency chip with high sensitivity, high packet rate, and low latency, making this flight controller the one that all Race/Freestyle pilots need! Suitable for use in Tiny whoop race or Toothpick Freestyle, and can also be used in 1S ultra-lightweight Nano Long Range platform.



  • 2.4GHz ExpressLRS receiver is equipped with the SX1280 radio frequency chip with high sensitivity, high packet rate, and low latency
  • Onboard SPI-controlled 2.4GHz ExpressLRS receiver
  • Ultra-small size and ultra-stable remote control range
  • Onboard Voltage and Amperage meters
  • World's first 5-in1 AIO FC w/ Receiver
  • 5.8GHz 40ch video transmitter
  • Dshot protocol 4-in-1 ESC
  • Onboard 4-in-1 ESC
  • F4 Flight Controller
  • Betaflight OSD



  • Bind with: Happymodel ES24TX, ES24TX Lite, ES24TX Slim, and DIY 2.4GHz ELRS TX module(need to flash the same version ELRS firmware)
  • Packet Rate option: 25Hz/50Hz/150Hz/250Hz/500Hz
  • Receiver protocol: SPI ExpressLRS
  • Telemetry output Power: <12dBm
  • Antenna: SMD antenna
  • RF Frequency: 2.4GHz


  • Built-in 5V 1A BECFlight controller firmware target: CRAZYBEEF4SX1280
  • Built-in 5A(each) Blheli_S 4in1 ESC Dshot600 ready
  • MCU:STM32F411CEU6 (100MHZ, 512K FLASH)
  • Power supply: 1S battery input (DC 2.9V-4.35V)
  • Built-in SPI ExpressLRS 2.4GHz receiver
  • Sensor: MPU-6000(SPI connection)
  • Built-in Betaflight OSD(SPI Control)
  • Original whoop size compatible
  • Built-in 5.8G VTX


  • Frequency: 5.8GHz 5bands 40 channels (include Race band) Smart audio ready
  • Output power: 25mw~200mw switchable
  • Current consumption: 300mA(type)
  • Input voltage: 3.3V 5.5V
  • Frequency: 40CH


  • Power supply: 1S LiPo/LiPo HVCurrent: 5A continuous peak 6A (3 seconds)
  • Factory firmware: O_H_5_REV16_8.HEX
  • Support BLHeliSuite programmable
  • MCU upgraded to EFM8BB21
  • Default protocol: DSHOT600


  • Amperage meter scale setting 1175
  • Voltage meter scale setting 110

Binding Procedure

  1. Power the flight controller by connecting USB. Please make sure that the port driver of the flight controller is correctly installed on the computer, then open Betaflight Configurator(Latest version) to connect, enter to the “receiver” interface, and then click “Bind Receiver”, the red LED at the bottom of the flight controller will flash quickly, which means that the SPI ELRS receiver enters the binding mode. There is another way to make the receiver enter the binding mode: after connecting to the Betaflight configurator, move to the CLI interface and enter “bind_rx” in the command line.
  2. After correctly connecting the ES24TX or ES24TX Lite/Slim module or DIY 2.4G ELRS TX module to your Opentx radio transmitter, copy the latest version of ELRS.LUA file to the SD card in the remote controller. The directory is “SD Card/Scripts/tools”, Then run ELRS.LUA and upgrade the specified TX firmware through Wifi, and then click “bind” to link with the SPI ExpressLRS receiver. The Red LED will blink slowly, this means the bind is successful. Note: You need to adjust the Packet Rate to 500Hz from the ELRS interface of your radio controller before binding.
  3. After the binding is successful, please re-power for the radio transmitter, and then the Red LED at the bottom of the flight controller will getting to be solid, and the telemetry can be received at the same time.
  4. The meaning of the LED status of the SPI receiver: the LED is getting to be solid, indicating that the bind is successful or the connection and communication is normal, the LED flashing quickly indicates that the receiver is in binding mode, and the LED flashing slowly indicates that the there is no signal received from the radio controller.
  • Note: Do not allow the antenna plug to touch the Motor soldering pins, as it may burn the ESC.



  • 1x Happymodel ExpressLRS F4 5A 5-in-1 AIO FC w/ Built-in 2.4GHz Rx
  • 1x Connecting Wire
  • 1x Dipole Antenna
  • 4x Damping Balls
  • 1x 3-Pin Wire
  • 5x Screws