Review: SpeedyBee F405 Mini Stack – The Cheapest 20x20mm Flight Controller and ESC in 2023

by Oscar
Speedybee F405 Mini Stack Flight Controller Esc

If you’ve been building FPV drones, you’d know the pain of constantly skyrocketing prices of their electronics. With global chip shortages and an high demand, prices of FPV components have surged. Enter SpeedyBee, aiming to redefine affordability without compromising on features with their new F405 Mini Stack. For under $60, we will find out if the Speedybee F4 Mini Stack delivers on its promises in this review.

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To learn more about FC and ESC, check out my buyer’s guide:

Where to Buy?

You can purchase the SpeedyBee F405 Mini Stack from these vendors:

Speedybee F405 Mini Stack Flight Controller Esc Unbox Accessories Parts

Alongside the FC/ESC stack, SpeedyBee ensures you have everything you need for installation:

  • Assortment of rubber gummies for both M2 and M3 mounting hardware, and screws and washers of both sizes.
  • An XT30 connector pigtail is included for the ESC, which makes it clear that this stack is designed for smaller drones. The cables are 65mm long, 16AWG silicone wires. For 5inch builds, consider upgrading to an XT60 which is not included.
  • A 35V 470uF low ESR capacitor, essential for reducing noise in the power supply.
  • There’s a QR code linking to manual and Speedybee app.

Specifications

SpeedyBee F405 Mini 20×20 Flight Controller:

  • MCU: STM32F405
  • IMU(Gyro): ICM42688P
  • USB Port Type: Type-C
  • Barometer: Built-in
  • Analog OSD Chip: onboard AT7456E chip
  • BLE Bluetooth: Supported for SpeedyBee App connection (Ensure UART 4 MSP switch is on and set at 115200 baud rate).
  • Wireless FC Firmware Flashing: NOT Supported. Use Betaflight configurator on PC.
  • Wireless Blackbox Download & Analysis: NOT Supported. Use Betaflight configurator on PC.
  • WIFI: Not supported
  • DJI Air Unit Connection Way: Direct soldering
  • DJI Air Unit Compatibility: Compatible with all DJI Air Units. Follow given solder pad instructions.
  • Blackbox: 8MB Onboard Flash
  • BetaFlight Camera Control Pad: Yes (CC pad on front side)
  • Current Sensor Input: Supported (For BLS 35A V2 ESC, set Scale=250 and Offset=-500)
  • Power Input: 3-6S LiPo
  • BEC:
    • 5V 2A
    • 9V 3A
    • 3.3V 500mA
    • 4.5V 1A
  • 4 Motor Outputs
  • 4 Spare UART’s
  • ESC Telemetry: UART 5 (R5)
  • I2C: Supported for magnetometer, sonar, etc.
  • LED Strip Pad: Supports RGB LED such as WS2812
  • Buzzer: Supported with BZ+ and BZ- pads
  • BOOT Button: Supported for firmware flashing in DFU mode
  • RSSI Input: Not Supported
  • Smart Port / F.Port: Not Supported
  • Supported Flight Controller Firmware: BetaFlight(Default), INAV
  • Firmware Target Name: SPEEDYBEEF405MINI
  • Mounting: 20 x 20mm with 3.5mm hole diameter; Compatible with M2 and M3 screws/Silicone grommets
  • Dimension: 30(L) x 32(W) x 7.8(H)mm
  • Weight: 9.6g

SpeedyBee 35A BLHeli_S Mini V2 4-in-1 ESC:

  • Firmware: BLHeli_S J-H-40
  • Continuous Current: 35A * 4
  • Burst Current: 45A (5 seconds)
  • ESC Protocol: DSHOT300/600
  • Power Input: 3-6S LiPo
  • Power Output: VBAT (Battery voltage for flight controller power)
  • Current Sensor: Support (Scale=250 Offset=-500)
  • Mounting: 20 x 20mm with ∅3.5mm hole size; Compatible with M2 and M3 screws/Silicone grommets
  • Dimension: 35 * 35 * 5.5mm
  • Weight: 7.2g

The stack (FC and ESC boards) without hardware weighs around 15.0g, slightly heavier than the claimed 13.5g by Speedybee.

Features

SpeedyBee has made a name for itself by consistently delivering budget-friendly flight controllers.

Their release last year, the SpeedyBee F4 V3 (a 30x30mm stack) tailored for 5-inch drones, created quite a buzz owing to its cost-effectiveness. They didn’t rest on their laurels, however. Shortly after, they introduced the F405 Wing APP Stack, another budget option but crafted especially for FPV wings and planes, which has been very popular as well. Now, with the introduction of the F405 Mini stack available under $60, they’re clearly pushing the boundaries of what’s possible in terms of value.

Here’s a glance at its standout features:

  • Supports all FPV systems: DJI, HDZero, Walksnail and analog
  • Battery level indication LEDs.
  • 4x UART’s.
  • Onboard 5V 2A and 9V 3A BEC.
  • Integrated barometer.
  • 8MB memory for Blackbox.
  • Onboard Tantalum capacitors for noise filtration.
  • Onboard TVS diode on the ESC for added protection.
  • USB-C connector.
  • SDA/SCL connection available.
  • 35A BLHeli_S 4in1 ESC, compatible with Bluejay.

Closer Look at the SpeedyBee F405 Mini Flight Controller

The F405 Mini Stack, with its 20x20mm mounting, is ideal for drone size ranging from 2 to 4 inches.

Speedybee F405 Mini Stack Flight Controller Esc Ribbon Cable Connection

Speedybee F405 Mini Stack Flight Controller Esc Grommets Gummies

The included 4in1 ESC is a 35A (per motor output), making it a good choice for powerful 3-inch and 4-inch micro builds. In fact, it’s among one of the highest amp rating ESCs in 20x20mm stacks – delivering remarkable bang for your buck.

You can probably use it on ultralight 5-inch if you manage to keep the weight down. However, if you’re aiming for a powerful 5-inch running 2207 motors, you might want something of higher current, such as 50A or 60A to ensure reliability.

Speedybee F405 Mini Stack Esc Blheli S Close Up Top

Speedybee F405 Mini Stack Esc Blheli S Close Up Bottom

Despite the compact form factor and affordability, this flight controller doesn’t skimp on features. Whether you’re a fan of analog or prefer to digital FPV system, this stack has you covered. It’s even optimized for digital VTX’s thanks to the 9V BEC and additional UART.

Speedybee F405 Mini Stack Flight Controller Close Up Top

Speedybee F405 Mini Stack Flight Controller Close Up Bottom

The solder pads are generously sized with clear labels making them beginner-friendly. The FC also uses USB-C Port, a upgrade both in terms of convenience and robustness over traditional micro USB ports.

Speedybee F405 Mini Stack Flight Controller Esc Usb Port

It’s using the ICM42688P Gyro, a popular choice in the latest FPV drone flight controllers.

There are battery level LED on the flight controller, a nice touch for those without a dedicated battery checker or OSD.

By powering your receiver and GPS using the onboard 4.5V pads, you don’t need to plug in the main battery to test them on the bench (or to get GPS locks in the field). It eliminates the need of having to power up other unnecessary components (such as the video transmitter), as you only need to plug in the USB cable.

Bluetooth Connection

The cherry on top? Its built-in Bluetooth feature. This allows you to configure settings via the SpeedyBee app on your phone.

For Bluetooth to work, ensure the MSP switch on UART 4 is turned on and set to a baud rate of 115200.

The Speedybee App is easy to use, the intuitive interface resembles the Betaflight Configurator and gives you the same settings. It’s handy when you need to change settings in the field, where you don’t have access to a computer, you can just do it on your phone.

Betaflight Configurations

Speedybee F405 Mini Stack Flight Controller Esc

The FC target for the SpeedyBee F405 Mini is SPEEDYBEEF405MINI and it comes pre-installed with the Betaflight 4.3.2 firmware.

In the Ports tab, it suggests there are six available UARTs. However, of those, only four UARTs can be directly accessed through the solder pads. To break it down further: UART1, 2, and 3 are full UARTs (both TX and RX pads are accessible), but UART6 is a half UART (only the TX6 is available without RX6).

How to Use

Check out the official manual for wiring diagrams.

Speedybee F405 Mini Stack Flight Controller Esc User Manual Instruction Wiring Diagram

Final Thoughts

With a price point under $60 for the Speedybee F405 Mini stack, this product offers excellent value. If you’re in the market for a feature-packed flight controller and ESC without breaking the bank, the SpeedyBee F4 Mini Stack is worth considering.

You can purchase the SpeedyBee F405 Mini Stack from these vendors:

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4 comments

Ramiro 11th March 2024 - 7:52 pm

Hello Oscar, we recently installed this stack on a Cinewhoop 3.5 Inch.
We have tried to flash Bluejay, to activate the Bidirectional Dshot, but in ESC-Configurator we have not been able to do it.
Is this ESC really compatible with Bluejay?

Reply
Oscar 13th March 2024 - 6:35 pm

Yes it is. What error are you getting?

Reply
Seth 17th August 2023 - 3:30 am

I am planning on doing a 3.5″ cinewhoop build with this. Would it be okay if I swap to an xt60 cable and use 6s batteries?

Reply
Oscar 21st August 2023 - 4:16 pm

You can keep the XT30 even for 6S. Current draw isn’t that high with 3.5″ quads. For example this is my 3.5″ build on 6S and this stack would also work perfectly in it: Build: Volador VX3.5 FPV Drone with DJI O3 and Zeus F7 Mini Stack (3.5inch Digital Micro Quad)

Reply