Happymodel ELRSF4 AIO Flight Controller 2.4GHz ELRS V3.1 V3.3 | 5-in-1 FCHappymodel ELRSF4 2. 4GHz AIO 5 in 1 FC Youre here to buy the Happymodel ELRSF4 2. 4GHz AIO flight controller, and yeswere here to sell it, because five boards pretending to be one is peak tiny whoop evolution. This is the worlds first 5 in 1 F4 AIO with SPI ExpressLRS 2. 4GHz, a 4 in 1 ESC, OpenVTX, Betaflight OSD, and zero patience for bulky stacks. Built for whoop racing, toothpick freestyle, and 1S nano long range dreams. Why You Want It This

Happymodel ELRSF4 2.4GHz AIO 5-in-1 FC

You’re here to buy the Happymodel ELRSF4 2.4GHz AIO flight controller, and yes—we’re here to sell it, because five boards pretending to be one is peak tiny-whoop evolution. This is the world’s first 5-in-1 F4 AIO with SPI ExpressLRS 2.4GHz, a 4-in-1 ESC, OpenVTX, Betaflight OSD, and zero patience for bulky stacks. Built for whoop racing, toothpick freestyle, and 1S nano long-range dreams.

Why You Want It

This board exists to simplify your build and complicate your excuses. With an STM32F411 running Betaflight, SX1280-based SPI ELRS for low latency, and an onboard 0–400mW OpenVTX, you get range, clarity, and fewer solder joints to mess up. V3.1 or V3.3—either way, you’re getting a modern gyro because the MPU6000 retired and went fishing.

Specifications

• MCU: STM32F411CEU6 @100MHz (small board, big energy)
• Gyro: ICM20689 (V3.1) / BMI270 or ICM42688P (V3.3)
• Firmware Target: CRAZYBEEF4SX1280 (say it fast)
• Power Input: 1S LiPo/LiHV 2.9–4.35V (whoop life)
• ESC: 4-in-1 BLHeli_S, 5A continuous, 6A burst (tiny but brave)
• ESC Protocol: DSHOT600 (because latency matters)
• Receiver: SPI ExpressLRS 2.4GHz (bind once, forget forever)
• ELRS Packet Rates: 25–500Hz (pick your poison)
• VTX: 5.8GHz OpenVTX 0–400mW, 48CH (indoor to outdoor)
• OSD: Built-in Betaflight OSD (SPI controlled, obviously)
• BEC: 5V 1A (enough, not greedy)
• Telemetry Power: <12dBm (efficient, not shouty)

Onboard ESC Details

• ESC MCU: EFM8BB21 (upgraded, not nostalgic)
• Firmware: O_H_5_REV16_8.HEX (factory)
• Programmable: BLHeliSuite (tweak responsibly)

Onboard VTX Details

• Output Power: 0–400mW switchable (legal where applicable)
• Bands: 6 bands, 48 channels incl. Raceband
• Control: Smartaudio V2.1 ready

Compatibility

Original whoop size compatible. Perfect for Tiny Whoop racing, Toothpick freestyle, and 1S ultra-light nano long-range builds that make zero sense and all the fun.

Bind 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(Recommend 10.8.0) 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 bind mode. There is another way to make the receiver enter the bind mode: after connecting to the Betaflight configurator, move to the CLI interface and enter “bind_rx” in the command line.
2. Make sure you already upgrade the elrs tx firmware to V2.0 version. After correctly connecting ELRS TX module to your radio transmitter, copy ELRSV2.LUA file to the SD card in the radio transmitter. The directory is “SD Card/Scripts/tools”, Then run ELRSV2.LUA, and then click “bind” to link with the SPI ExpressLRS receiver.  The Red LED will blinking slowly, this means the bind is successfully.
3. After binding successfully, please re-power for the radio radio transmitter and then the Red LED at the bottom of the flight controller will getting to be solid, and the telemetry could 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.

Firmware, hex file and default diff download
http://www.happymodel.cn/index.php/2022/02/23/elrsf4-2g4-v3-1-flight-controller-firmware-and-default-factory-diff/

Online configurator here

https://config.bosshobby.com

What’s in the Box*

• 1× ELRSF4 2.4GHz AIO 5-in-1 Flight Controller

Disclaimer

Component revisions may vary (thanks, global supply chains), but performance, features, and your ability to crash remain fully intact.

Notes: Due to the high-power VTX onboard, the temperature of the AIO flight controller will be relatively high in the standby state, and the camera signal may be lost after a couple of minutes standby. This is a normal phenomenon, please don’t worry. We strongly recommend using a fan to cool down when setting up the flight control. Please make sure the vtx antenna was plugged before power for the AIO flight controller.

Since Betaflight has not yet released the official firmware that could supports the SPI Expresslrs protocol, the current version is the Beta version(Target:CrazybeeF4SX1280). Betaflight will update to their official target soon. Please feel free to contact with us if you have any issues with this Beta version Firmware.

Please change the “PID loop frequency” to “2kHz” , sometimes it would make the SPI receiver not working correct while the value is “8kHz”

Still Here?

You read the whole spec sheet—respect. If you want fewer wires, more range, and a board that does almost everything except fly itself, this ELRSF4 AIO is your sign. Grab one and stop pretending your current build is “temporary.”