1. Introduction
This manual provides detailed instructions for the SpeedyBee F405 V3 and V4 Flight Controller (FC) and Electronic Speed Controller (ESC) Stack. Designed for RC FPV racing and freestyle drones, this stack offers robust performance, wireless configuration via Bluetooth, and advanced features for an enhanced flying experience. Please read this manual thoroughly before installation and operation to ensure proper functionality and safety.
2. Package Contents
Verify that all items are included in your package based on the chosen stack version.
SpeedyBee BLS 50A 4-in-1 ESC Package Contents:
- SpeedyBee BLS 50A 4-in-1 ESC x 1
- 35V 1500uF Low ESR Capacitor x 1
- M3 silicone O Ring x 5
- XT60 Power Cable (70mm) x 1
- SH 1.0mm 30mm-length 8pin Cable (for FC-ESC connection) x 1
- M3*8.1mm Silicone Grommets (for ESC) x 5
SpeedyBee F405 V3 50A 30x30 Stack Package Contents:
- SpeedyBee F405 V3 Flight Controller x 1
- SpeedyBee BLS 50A 4-in-1 ESC x 1
- 35V 1500uF Low ESR Capacitor x 1
- M3 Nylon Nut x 5
- M3 silicone O Ring x 5
- M3*8mm Silicone Grommets (for FC) x 5
- M3*8.1mm Silicone Grommets (for ESC) x 5
- SH 1.0mm 15mm-length 8pin Cable (for FC-ESC connection) x 1
- M3*30mm Inner-hexagon Screws x 5
- DJI 6pin Cable (80mm) x 1
- XT60 Power Cable (70mm) x 1
3. Specifications
3.1 ESC Specifications
| Feature | SpeedyBee BLS 55A ESC (in F405 V4 stack) | SpeedyBee BLS 50A ESC (in F405 V3 stack) |
|---|---|---|
| Continuous Current | 55A | 50A |
| Burst Current | 70A (10S) | 55A (5S) |
| PCB inner layer copper thickness | 3oz | 2oz |
| Aluminum Alloy heatsink | ✓ | x |
| MOSFET internal resistance | 1.1mR | 1.5mR |
| Number of TDK MLCC 35V 22uF filtering capacitors | 21 | 16 |
| MOSFET Voltage Rating | 40V | 40V |
| Bidirectional DShot | Supported if flashed with BlueJay | Supported if flashed with BlueJay |
| TVS Protective diode | ✓ | ✓ |
| External Low ESR Capacitor in the Package | 1000uF | 1000uF |
| ESC Protocol | DSHOT300/600 | DSHOT300/600 |
| Firmware | BLHeli-S 8-bit J-H-40 | BLHeli-S J-H-50 |
| Power Input | 3-6S LiPo | 3-6S LiPo |
| Power Output | VBAT | VBAT |
| Mounting | 30.5 x 30.5mm (4mm hole diameter) | 30.5 x 30.5mm (4mm hole diameter) |
| Dimension | 45.6(L) * 44(W) * 8mm(H) | 45.6(L) * 44(W) * 6.1mm(H) |
| Naked PCB board weight | 18.7g | 13.8g |
| Heatsink weight | 4.3g | x |
| Weight with Heatsink | 23.5g | 13.8g |
3.2 Flight Controller Specifications
| Feature | SpeedyBee F405 V4 FC | SpeedyBee F405 V3 FC |
|---|---|---|
| MCU | STM32F405 | STM32F405 |
| Gyro | ICM42688P | BMI270 |
| 100uF filtering tantalum capacitor for Gyro | ✓ | x |
| LDO power chip for Gyro | Maxliner brand. Surge protection 320% better | Regular LDO power chip |
| Individual 3.3V LDO for MCU | ✓ | ✓ |
| 5V BEC Output | 9 groups. 3A in total. | 9 groups. 2A in total. |
| 9V BEC Output | 2 groups. 3A in total. | 2 groups. 2A in total. |
| INAV quadcopter DShot Support | ✓ | Only Multishot, OneShot125 |
| SD Card compatibility | ✓ | Not very well with certain microSD cards |
| Bluetooth Chip | Supported. Used for FC configuration | Supported. Used for FC configuration |
| 4-level Battery Life Indicator | ✓ | ✓ |
| Blackbox Storage | MicroSD Card Slot | MicroSD Card Slot |
| ESC Signals | M1-M8 | M1-M8 |
| 4x LED strips Support | ✓ (pads) | ✓ (pads) |
| Barometer | Built-in | Built-in |
| USB Port Type | Type-C | Type-C |
| Power Input | 3S - 6S Lipo | 3S - 6S Lipo |
| 4.5V BEC Output for GPS | ✓ | ✓ |
| 3.3V BEC Output | ✓ | ✓ |
| I2C (Magnetometer, Sonar, etc) | ✓ | ✓ |
| Buzzer | ✓ | ✓ |
| BOOT Button | ✓ | ✓ |
| RSSI Input | ✓ | ✓ |
| Mounting | 30.5 x 30.5mm (4mm hole diameter) | 30.5 x 30.5mm (4mm hole diameter) |
| Dimension | 41.6(L) x 39.4(W) x 7.8(H)mm | 41.6(L) x 39.4(W) x 7.8(H)mm |
| Weight | 10.5g | 9.6g |
3.3 Dimensions
4. Setup and Wiring
4.1 Connection with FC & Motors
It is strongly recommended to use the Low ESR capacitor included in the package to prevent the stack from being burnt out by voltage spikes during power-up. The FC and ESC can also be connected via direct soldering if preferred. Refer to the soldering pads definition in the diagrams below.
4.2 Wiring Diagram
The following diagrams illustrate the comprehensive wiring for various peripherals. Ensure all connections are made accurately.
F405 V4 Flight Controller Wiring Diagram
F405 V3 Flight Controller Wiring Diagram
4.3 SBUS Receiver Connection Notice
When using an SBUS receiver, the SBUS signal wire of the receiver must be connected to the SBUS pad on the front side of the flight controller (this pad internally uses UART2).
If you are also using the DJI Air Unit (O3/Link/Vista/Air Unit V1), you will need to disconnect the SBUS signal wire from the Air Unit harness. Failure to do so will prevent the SBUS receiver from being properly recognized by the flight controller. You can use tweezers to pick out the SBUS wire from the 6-pin harness connector (or directly cut this wire) and insulate the exposed part of the wire carefully.
SBUS Receiver Connection for F405 V4 FC
SBUS Receiver Connection for F405 V3 FC
4.4 DJI Air Unit Connection
The DJI Air Unit plug is completely compatible with DJI O3/RunCam Link/Caddx Vista/DJI Air Unit V1, requiring no wire changes.
4.5 Flight Controller Layouts
F405 V3 Flight Controller Layout
BLS 50A 4-in-1 ESC Layout
F405 V4 Flight Controller Layout
BLS 55A 4-in-1 ESC Layout
5. Operation
5.1 Configure FC and ESC via Bluetooth
The SpeedyBee app allows you to wirelessly configure your Flight Controller and ESC. Connect your smartphone to the stack via Bluetooth to tune your quad anytime, anywhere.
5.2 Change Motor Directions Wirelessly
After building or replacing a motor, you can easily change motor directions wirelessly using the SpeedyBee app. This feature works for all BLHeli32, BLHeli_S, and BlueJay ESCs. To use this feature, go to the App > Motors > Motor Direction Settings.
5.3 LED Pads with Simple Switching
The FC features 4 sets of LED pads. Solder your LED strips to these pads for enhanced visibility. With a single tap on the BOOT button, you can cycle through different LED presets. A long press on the BOOT button switches to Betaflight LED mode.
5.4 Onboard Battery Life Indicator
The flight controller includes a 4-level LED battery capacity indicator. Connect your battery, and the LEDs will instantly show the battery level, eliminating the need for an external LiPo checker.
5.5 Support for 8 Motors (X8/Y6/Fixed-Wings)
Both V3 and V4 flight controllers support 8 motors, making them suitable for X8 drones, Y6 drones, or fixed-wing aircraft. You can configure these setups directly through the SpeedyBee app.
6. Maintenance
- Firmware Updates: Regularly check the SpeedyBee website or app for the latest firmware updates to ensure optimal performance and access to new features.
- Cleaning: Keep the FC and ESC free from dust, dirt, and moisture. Use a soft, dry brush or compressed air for cleaning. Avoid using liquids.
- Physical Inspection: Periodically inspect all solder joints and connections for any signs of damage or corrosion. Ensure all screws and grommets are securely in place.
- Storage: Store the stack in a dry, cool environment away from direct sunlight and extreme temperatures.
7. Troubleshooting
7.1 Common Issues and Solutions
- SBUS Receiver Not Recognized (with DJI Air Unit): If your ELRS receiver is not recognized when using a DJI Air Unit, ensure the SBUS signal wire from the Air Unit harness is disconnected from the flight controller. This wire can interfere with the external SBUS receiver. Carefully remove or cut and insulate this wire.
- Voltage Spikes/Burnout: Always use the provided Low ESR capacitor with the ESC to protect against voltage spikes, especially during power-up.
- SD Card Issues (F405 V3): The F405 V3 FC may have compatibility issues with certain microSD cards. Ensure your microSD card is Standard (SDSC) or High Capacity (SDHC) and formatted with FAT16 or FAT32. Extended capacity cards (SDXC) are not supported. For F405 V4, compatibility is improved, supporting C4, C6, C10, and higher cards.
- No Heat/Overheating: The V4 ESC is designed with an aluminum alloy heatsink for efficient MOSFET heat dissipation, ensuring stable operation without excessive heat. If experiencing unusual heat, verify proper airflow and mounting.
8. User Tips
- Wireless Convenience: Leverage the SpeedyBee app's Bluetooth connectivity for quick field adjustments to your FC and ESC settings without needing a computer.
- Battery Monitoring: Utilize the onboard 4-level LED battery indicator on the FC to quickly check your LiPo battery status, reducing the need for a separate checker.
- Enhanced Protection: The V4 ESC features a TVS protective diode and numerous high-quality capacitors for superior surge protection and smoother flight performance.
- Blackbox Logging: Both V3 and V4 support Blackbox logging to a microSD card (up to 4GB). For V4, this feature is more reliable with improved SD card compatibility, allowing for extensive flight data analysis.
9. Warranty and Support
For technical support, troubleshooting assistance, or warranty inquiries, please contact SpeedyBee customer service through their official website or authorized distributors. Keep your proof of purchase for any warranty claims.
