Flywoo GOKU GN405 Nano HD 20A Stack V3 W/ TXCO ELRS 2.4g

Highlights：

● 16x16 mounting holes with a compact design

● Built-in TCXO ELRS receiver

● Direct plug-in for DJI O3\O4  Air Unit

● FC/ESC pin header interface, compatible with QUAD/HEX

● Built-in barometer

● Equipped with a 16MB black box

● Universal USB-C interface

Upgrade Your Flight: Versatile ESC Options to Meet Every Need

The GOKU GN405 HD Stack V3 series offers three ESC options to match different drone sizes and performance needs, giving pilots maximum flexibility in build design. 

The 20A QUAD version provides a balanced solution for lightweight 2–4S quad builds, combining efficiency and stability in a compact footprint — ideal for sub-250g and cinematic FPV drones.

The 20A HEX version features a built-in 6-in-1 BLHeli_S ESC, optimized for compact 2–4S hex builds. It supports multiple protocols, including PWM, Oneshot, Multishot, and DShot up to DShot600, delivering smooth and efficient power control in micro FPV setups. 

The 35A QUAD version is designed for high-performance 2–6S freestyle drones, offering stronger current handling for aggressive flying while maintaining stable and responsive throttle output. 

Check out our FPV Stack, all FPV Flight Controller Collection and the rest of our Flywoo Products!

Integrated TCXO 2.4GHz ELRS for Stable and Reliable Control

The flight controller features a built-in TCXO (Temperature Compensated Crystal Oscillator) 2.4GHz ExpressLRS receiver, significantly improving signal accuracy and long-range stability. Compared to standard receivers, TCXO technology ensures more precise frequency control, reducing drift caused by temperature changes and improving overall link reliability. This integration also eliminates the need for external receiver wiring, resulting in a cleaner and more efficient build with fewer soldering points.

Clean Power Design for a Smoother Flying Experience

A well-optimized power supply system ensures stable voltage delivery across the stack, reducing electrical noise and improving overall flight performance. This clean power architecture helps minimize interference between components, resulting in smoother control response and more consistent flight behavior — especially important for HD digital FPV systems.

Advanced Features for Performance, Connectivity & HD FPV Integration

This flight controller combines powerful features to enhance tuning, usability, and flight experience. A 16MB Blackbox provides detailed flight data for precise PID tuning and performance analysis. The USB-C interface ensures faster, more stable connections and easier setup compared to traditional ports. It supports both quad and hex configurations, offering flexibility for different FPV builds. With native DJI O3 Air Unit compatibility, it enables plug-and-play HD video transmission with low latency and stable performance.

Buying Guide: Flywoo GOKU GN405 Nano HD 20A Stack V3

The Flywoo GOKU GN405 Nano HD 20A Stack V3 is built for pilots who want a compact digital FPV stack without adding unnecessary weight. Its 16×16mm mounting pattern, integrated TCXO ELRS receiver and direct DJI O4/O4 Pro connection make it particularly suitable for small 2–4S builds where installation space is limited.

MEPSKING Expert Assessment

The biggest advantage of the GN405 Nano HD 20A is size-to-function efficiency.

The FC measures only 25 × 23 × 8mm and uses 16×16mm mounting holes, while the FC+20A combination is listed at approximately 7.8g. Despite its small size, the FC includes an ICM42688P gyro, barometer, 16MB Blackbox, six UARTs and built-in TCXO ELRS 2.4GHz.

This makes the stack particularly attractive when building a lightweight digital quad where a conventional 20×20 or 30×30 stack would take up unnecessary space.

The main limitation is the 20A ESC. The FC itself accepts 2–6S input, but the 20A ESC is rated for 2–4S LiPo, so the complete 20A stack should be selected for 2–4S builds rather than 6S.

Which GN405 Stack Should You Choose?

The GN405 20A is the choice when low weight and compact installation matter most.

Choose the GN405 35A when the frame and motors require more current headroom. The two GN405 versions share the same compact 16×16 FC platform, but the 35A ESC provides substantially more current capacity while adding only a small amount of weight compared with the 20A version. Flywoo lists the FC+35A combination at approximately 6.5g for the FC+ESC component configuration, versus 7.8g for FC+20A in its specification table; because these figures are presented for the individual configurations, buyers should compare the complete package rather than treating them as directly equivalent finished-stack weights.

Choose the F722 Pro Mini V2 45A when you are building a larger or more demanding quad and want a 20×20mm installation with a faster F722 processor, 45A AM32 ESC and 2–6S support. The F722 Pro Mini V2 also provides 8 motor outputs and dual 4-in-1 ESC sockets, making it much more expandable than the GN405 Nano platform.

20A or 35A: How Should You Choose?

For most compact 2–4S builds, 20A is enough when the motors and propellers are matched appropriately.

Choose 20A when:

● The build uses small motors and relatively low-current propellers.

● Weight reduction is important.

● You are building a lightweight 2–4S digital quad.

● The frame uses 16×16mm mounting.

● You want the simplest compact O4/O4 Pro installation.

Choose 35A when:

● Motors can draw significantly higher current.

● You use larger or more aggressive propellers.

● You fly aggressively and want more ESC headroom.

● The additional ESC capacity is more important than saving every gram.

The important point is that 35A does not automatically make the drone faster. If the motors never approach the 20A ESC's practical limits, the additional current rating provides little performance benefit.

GN405 Nano HD vs F722 Pro Mini V2

The GN405 and F722 Pro Mini V2 target different build priorities.

The GN405 Nano HD is about compact integration. Its 16×16 mounting, built-in TCXO ELRS and direct DJI digital-video connection make it particularly attractive for smaller builds where space is limited.

The F722 Pro Mini V2 is designed for higher-performance and more expandable builds. It uses a 20×20mm mounting pattern, STM32F722 processor, ICM42688 gyro, 45A AM32 ESC and 2–6S input, making it more appropriate for demanding 5-inch or higher-power applications.

So the choice is straightforward:

Small and lightweight → GN405 20A

Small but higher-current → GN405 35A

Larger, 6S and higher-power → F722 Pro Mini 45A

Compatibility and Installation

● Confirm that the frame uses the 16×16mm M2 mounting pattern for the GN405.

● The complete GN405 20A stack should be used with 2–4S LiPo, because the ESC is rated for 2–4S even though the FC accepts up to 6S.

● The built-in TCXO ELRS 2.4GHz receiver eliminates the need for a separate ELRS receiver in compatible builds.

● DJI O4/O4 Pro can be connected through the dedicated Plug&Play interface.

● Check motor current and propeller load before choosing between the 20A and 35A ESC.

● Use the included soft mounting hardware and ensure the stack does not contact the carbon-fiber frame directly.

MEPSKING Purchase Verdict

Buy the Flywoo GOKU GN405 Nano HD 20A Stack V3 when you are building a compact 2–4S digital FPV drone and want to keep the electronics small and lightweight without giving up built-in TCXO ELRS or DJI O4/O4 Pro Plug&Play connectivity.

Choose the GN405 35A if your motors and propellers need more current headroom. Choose the F722 Pro Mini V2 45A when you are moving into a larger 20×20mm, 5-inch or 6S-oriented build where ESC capacity and processing resources matter more than the GN405's ultra-compact footprint.

For a lightweight 2–4S O4/O4 Pro build, the GN405 Nano HD 20A is the most compact choice; for higher current, step up to 35A.

Specifications

Layout

Wiring Diagram

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