AIO Flight Controller Guide — Whoop, Toothpick & 5″ Boards

What “AIO” means

An AIO (all-in-one) flight controller carries the gyro, processor and a 4-in-1 ESC on a single board. Some add the radio receiver, and whoop boards add the video transmitter too — a “5-in-1” that leaves only the camera and motors to plug in. One board, one set of screws, no ribbon cable: that is why every tiny whoop and most sub-250 g builds use one.

The three sizes of AIO

Class	Mount	ESC	Battery	Typical boards
65–75 mm tiny whoop	25.5 × 25.5 mm, M2	5–18 A	1S (some 1–2S)	NewBeeDrone Hummingbird V4 (F411, 12 A, ELRS, 25–400 mW VTX), Hummingbird RaceSpec V2 (AT32, 18 A), Flywoo GOKU F405 ERVT (5 A, 5-in-1)
2–3.5″ toothpick / micro	25.5 × 25.5 or 20 × 20 mm	12–30 A	2S–4S	HGLRC Specter F411 12 A, iFlight BLITZ D25 HD 20 A, Caddx SuperF405HD (ELRS, Walksnail), TBS Podracer 30 A
3.5–5″ freestyle	25.5 × 25.5 or 30.5 × 30.5 mm	35–55 A	2S–6S	iFlight Beast F7 55 A, BLITZ Whoop F7 55 A, NeutronRC F722 / H743 45 A, MicoAir H743 45 A, Foxeer Reaper F745 45 A, Diatone MAMBA MK5 G4 40 A, HGLRC Specter F722 40 A (6-in-1)

The amp rating is per motor, continuous, the same rule as a separate 4-in-1 — the 4-in-1 ESC guide has the motor-to-ESC table. A 5″ 6S quad on a 45 A AIO is fine for freestyle; for racing motors that pull 50 A each, a 60–80 A stack is the safer buy.

AIO vs stack: the honest trade

Weight and height. One board saves 5–10 g and a stack’s worth of standoffs — decisive on a sub-250 g build, irrelevant on a 5″ freestyle quad.
Cost. An AIO is usually cheaper than FC + ESC bought separately and close to the price of a budget stack.
Repair. Burn one ESC channel on an AIO and the whole board, gyro included, goes in the bin. On a stack you replace the ESC alone.
Heat. The FETs sit next to the gyro. Good AIOs isolate it with soft mounts and a thicker board; cheap ones drift when hot.
Ports. F411 AIOs have two or three UARTs — receiver, VTX and GPS already fill them. F405, F722 and H743 boards give you five or more.

Integrated receiver and VTX

Whoop AIOs commonly include an ELRS 2.4 GHz receiver and a 25–400 mW analog VTX. That removes two solder jobs and two antennas’ worth of weight, at the cost of choice: you are committed to ELRS 2.4 and analog video for the life of the board, and a VTX failure is a board failure. For digital whoops the pattern is an AIO with built-in ELRS and a separate O4 or Walksnail air unit (Caddx SuperF405HD, BetaFPV and Flywoo O4 builds). In our catalogue both are filters on AIO boards; the kit builder needs them when it drops the receiver and VTX slots on a micro build.

Processor and gyro, briefly

F411 boards run Betaflight well on a whoop and are the cheapest; they run out of UARTs and flash first. F405 and AT32F435 are the current mid-range. F722 / F745 give headroom for RPM filtering and HD OSD. H743 is overkill for a whoop and right for a 3.5–5″ build you want to run Betaflight, INAV or ArduPilot on later. Gyros: ICM42688P and BMI270 are the current standard; MPU6000 is older and still fine. Dual-gyro boards (NeutronRC H743) are a racing nicety.

Mounting patterns

25.5 × 25.5 mm with M2 holes is the whoop standard (Hummingbird, Air65 / Meteor65 frames, Pavo20). Many 25.5 boards come with M3 grommets so they also fit 20 × 20 frames. Full-size 5″ AIOs use 30.5 × 30.5 mm. Check the frame’s stack pattern first; whoop frames and micro frames list it.

Buying checklist

Battery cells the board accepts (1S whoop boards die on 2S).
ESC amps ≥ motor max current with margin.
Receiver built in? Which protocol and band — must match your radio.
VTX built in? Analog power range; or a pad set for an HD air unit.
Mount pattern and the hole size of your frame.
Motor connectors: plug-in (whoop) or solder pads; a 1S whoop board with 1.0 mm plugs saves a lot of grief.

Pair the board with whoop and micro motors, 1S whoop batteries and a 1S charger, or skip the build and start from a bind-and-fly whoop.

AIO Flight Controllers: Whoop, Toothpick and 5-Inch All-in-One Boards Explained