Quick Answer
The SpeedyBee F405 family is the most confusingly-named flight controller line we stock, but the choice comes down to three things: form factor (AIO vs stack vs FC-only), frame size (20x20 for whoops, 25.5x25.5 for 2.5-3", 30x30 for 5"), and ESC amperage. For most 5-inch freestyle builds, grab the F405 V5 OX32 55A stack. For cinewhoops and 2.5-3" builds, the F405 AIO V2 35-40A at 25.5x25.5 is the one we reach for.
Why the SpeedyBee F405 Lineup Confuses Everyone
SpeedyBee's naming makes zero sense. The handle says "v4" but the product title says "V5." There are two different AIO variants with the same chip but different ESC firmware. The "Mini" has nothing to do with the "V4 Mini." We field questions about this every week, so let's sort it out properly.
Every SpeedyBee F405 board shares the same DNA: STM32F405 MCU, built-in Bluetooth for wireless tuning via the SpeedyBee app, AT7456E OSD chip, Type-C USB, and DJI Air Unit plug-and-play compatibility. The Bluetooth tuning is SpeedyBee's killer feature. You can change PID values, adjust rates, and flash ESC firmware from your phone at the flying field without dragging a laptop along.
Where they differ is mounting size, gyro, ESC integration, and how many UARTs they give you. Here's the breakdown.
By Mounting Size and Form Factor
30x30 Stacks (5-Inch Freestyle and Larger)
These are your full-size stacks for 5-inch and bigger builds. The FC sits on standard 30x30 standoffs with a separate ESC below it.
| Product | ESC | Gyro | Price |
|---|---|---|---|
| F405 V5 Deluxe Stack | 60A BLS | ICM42688P | £69.99 |
| F405 V5 OX32 55A Stack | 55A BLS | ICM42688P | £64.98 |
| F405 V3 BLS 60A Stack | 60A BLS | BMI270 | ~£55 |
| F405 V4 FC (no ESC) | None | ICM42688P | £33.99 |
We'd pick the 55A stack for most 5-inch freestyle builds. 55A is plenty for typical 5-inch freestyle on 6S with 2306 motors. The 60A version makes sense if you are running aggressive 6S bando bashing or high-KV racing motors that pull serious current. For the full picture on ESC firmware compatibility, see our ESC firmware comparison guide.
The V3 stack uses the older BMI270 gyro and BMP280 barometer. It works fine, but the ICM42688P on the V4 and V5 boards is what Betaflight filters are now tuned for. We'd pay the extra few quid for the newer gyro. Our F4 vs F7 vs H7 guide covers the processor differences if you want the deep dive. Browse all options in our flight controller collection.
25.5x25.5 AIO Boards (2.5 to 3.5-Inch Cinewhoops)
AIO boards combine FC and ESC on one PCB at 25.5x25.5 mounting. These are what you want for cinewhoop builds like the SpeedyBee Bee25 or similar 2.5-3" platforms.
| Product | ESC | Gyro | Price |
|---|---|---|---|
| F405 AIO 40A Bluejay | 40A Bluejay | ICM42688P | £47.90 |
| F405 AIO V2 35-40A | 35-40A Bluejay | ICM42688P | £43.49 |
These two are nearly identical. Both run ICM42688P, 3-6S input, 4 UARTs, and Bluetooth. The V2 adds a dual BEC setup (5V and 9V rails). For cinewhoop builds where you need clean 5V for a DJI O4 unit and 9V for accessories, the AIO V2 is the better pick. It has 12K+ impressions on our product page for a reason: this is the sweet spot for sub-4-inch digital builds.
20x20 Mini Boards (Whoops and Toothpicks)
For 65-85mm whoops and micro toothpick builds, you need 20x20 mounting. SpeedyBee offers both FC-only and stack options.
The F405 Mini FC at £28.75 is one of the cheapest F405 boards you can buy with ICM42688P and Bluetooth. Pair it with a BLS 35A V2 20x20 ESC for a complete micro stack. Or grab the Mini BLS 35A stack as a pre-bundled kit at £53.90. See our AIO vs stack guide for when a combined board makes sense vs separate components.
Fixed-Wing Special: F405 WING APP
The F405 WING APP is a completely different animal. Six UARTs (double the quad boards), I2C for magnetometers and digital airspeed sensors, 12 PWM outputs for servos, and ADC inputs for analog airspeed. If you are building an RC plane or fixed-wing FPV platform, this is the only SpeedyBee F405 that makes sense.
What We Would Actually Buy
5-inch freestyle: The F405 V5 55A stack. ICM42688P, Bluetooth tuning, 55A is more than enough for 6S freestyle, and under £65.
Cinewhoop (2.5-3.5"): The F405 AIO V2. Dual BEC, 25.5x25.5, ICM42688P, 35-40A is right for 14xx-15xx motors on 4S.
Whoop or micro toothpick: The F405 Mini FC plus a separate 20x20 ESC. Cheapest entry to F405 with ICM42688P.
Fixed-wing: The F405 WING APP. No substitute: it has the UART count and PWM outputs that wing builds demand.
FAQ
Q: What is the difference between SpeedyBee F405 V3, V4, and V5?
The V3 uses a BMI270 gyro and BMP280 barometer. The V4 and V5 both use the ICM42688P gyro with SPA06 barometer. Betaflight's filter defaults are tuned for the ICM42688P, so we recommend V4 or V5 over V3 for cleaner flight logs.
Q: Does the SpeedyBee F405 support DJI O4 Air Unit?
Yes. All SpeedyBee F405 boards have a 6-pin DJI Air Unit connector for plug-and-play digital FPV. No soldering required for the VTX link.
Q: Can I use SpeedyBee F405 with ArduPilot or iNav?
The F405 WING APP is designed for ArduPilot and iNav on fixed-wing builds with its extra UARTs and I2C. The quad FC boards work with Betaflight out of the box. Target files for ArduPilot are community-maintained but not officially supported by SpeedyBee.
Q: Do I need a separate ESC with the FC-only boards?
Yes. The FC-only boards (V3, V4, Mini FC) require a separate 4-in-1 ESC. Match the ESC amperage to your motors: 35A for 2-3 inch, 50-55A for 5-inch freestyle, 60A for aggressive 6S builds.