9IMOD F722 Mini Flight Stack User Manual

1. Introduction

The 9IMOD F722 Mini Flight Stack is a high-performance integrated solution for FPV racing drones, combining an F722 Mini Flight Control unit with a 60A 4-in-1 Electronic Speed Controller (ESC). Designed for enthusiasts and professionals, this stack offers robust features, including an STM32F722RET6 master chip, ICM42688 gyroscope, and support for various open-source firmwares like Betaflight, ArduPilot, and INAV. Its compact 20x20mm mounting size makes it suitable for a wide range of FPV builds.

Figure 1: The 9IMOD F722 Mini Flight Stack.

2. Key Features

• Open-source Firmware Support: Compatible with Betaflight, ArduPilot, and INAV.
• High-Performance Flight Controller: Equipped with STM32F722RET6 master chip, ICM42688 gyroscope, and BMP280 barometer.
• Integrated OSD: Built-in OSD module for easy parameterization.
• Robust 4-in-1 ESC: 60A continuous current, 3-8S Lipo support, BlueJay firmware, DSHOT300/600 motor protocol, and TVS protection diode.
• Optimized Design: Efficient PCB layout with large solder pads for easier assembly.
• Versatile Connectivity: Standard sockets and pads for various peripherals, including DJI Air Units and GPS modules (ubbox protocol).
• Compact Size: 20x20mm/M4 installation hole position.

Figure 2: Overview of the F722 Mini Flight Stack's rich features.

3. Specifications

3.1 F722 Flight Control Specifications

Figure 3: F722 Flight Control unit with detailed specifications.

3.2 60A ESC Specifications

Figure 4: 60A 4-in-1 ESC unit with detailed specifications, showing XT60 plug and capacitor.

4. Package Contents

The package typically includes the following items:

• 1x F722 Flight Stack (F722 Flight Control + 60A 4-in-1 ESC)
• Camera Connect Cable
• Analog Video Transmission Connect Cable
• Hex nuts (4 pieces)
• Silicone vibration absorbers (4 pieces)
• ELRS Receiver Connect Cable

Figure 5: F722 Mini Flight Controller and its accompanying accessories.

5. Setup and Wiring

Careful wiring is crucial for the proper functioning and safety of your FPV drone. Refer to the diagrams below for connecting various components to the F722 Mini Flight Stack.

5.1 Flight Controller Connections

This diagram illustrates the connections for your camera, OSD, LED, VTX, DJI Air Unit, GPS, and receiver to the F722 Mini Flight Controller.

Figure 6: Detailed wiring diagram for the F722 Mini Flight Controller.

• Camera: Connect 5-40V, GND, VIDEO, and OSD lines.
• GPS Module: Connect TX, RX, 5V, and GND. Ensure your GPS module supports ubbox protocol.
• Receiver (ELRS, Crossfire, etc.): Connect TX, RX, 5V, and GND.
• LED: Connect 5V, GND, and LED signal line.
• VTX/DJI Air Unit: Connect 12V, GND, and Video/Data lines as per the diagram.

5.2 Flight Controller and ESC Interconnection

The F722 Flight Control and 60A 4-in-1 ESC are designed to stack. Ensure correct orientation and secure connection between the two boards. The diagram below shows the signal and power connections between the FC and ESC, as well as motor connections from the ESC.

Figure 7: Interconnection diagram for the F722 Flight Controller and 4-in-1 ESC, including motor wiring.

• Stack Assembly: Mount the Flight Controller on top of the ESC, aligning the mounting holes (20x20mm/M4). Use the provided silicone vibration absorbers.
• Power Input: The ESC accepts 3-8S Lipo battery input. Connect your battery lead to the designated positive (+) and negative (-) pads on the ESC.
• Motor Connections: Connect your brushless motors to the M1, M2, M3, M4 pads on the ESC.
• Signal Connections: The FC and ESC connect via a ribbon cable or direct soldering pads for motor signals (1, 2, 3, 4) and telemetry.

6. Operation and Firmware

The 9IMOD F722 Mini Flight Stack supports various open-source firmwares, providing flexibility for different flight preferences and applications.

6.1 Firmware Flashing

The flight controller comes pre-flashed with Betaflight firmware (DAKEFPVF722 target). To update or change firmware:

1. Download the latest Betaflight Configurator, ArduPilot, or INAV software.
2. Connect the flight controller to your computer via the Type-C USB port.
3. Follow the specific instructions for your chosen firmware to flash the new version. Ensure you select the correct target (DAKEFPVF722 for Betaflight).

6.2 ESC Firmware (BlueJay)

The 60A 4-in-1 ESC uses BlueJay firmware and supports bidirectional DSHOT. For ESC firmware updates or configuration, use the appropriate BlueJay configurator tool.

6.3 Configuration

After flashing firmware, use the respective configurator software (e.g., Betaflight Configurator) to set up your drone's parameters, including:

• PID tuning
• Receiver setup (e.g., SBUS, Crossfire, ELRS)
• OSD display settings
• Motor direction and calibration
• Mode assignments

7. Maintenance

To ensure the longevity and optimal performance of your F722 Mini Flight Stack:

• Keep Clean: Regularly inspect the boards for dirt, dust, or debris. Use compressed air or a soft brush to clean.
• Avoid Moisture: Protect the electronics from water and excessive humidity. Consider conformal coating for outdoor use in damp conditions.
• Inspect Connections: Periodically check all solder joints and connectors for looseness or damage. Re-solder or replace as necessary.
• Temperature Management: Ensure adequate airflow around the stack, especially during intense flights, to prevent overheating.
• Firmware Updates: Keep your flight controller and ESC firmware updated to benefit from performance improvements and bug fixes.

8. Troubleshooting

If you encounter issues with your F722 Mini Flight Stack, consider the following common troubleshooting steps:

• No Power:
  • Check battery connection and voltage.
  • Inspect power leads for continuity and proper soldering.
  • Verify no short circuits on the board.
• Motors Not Spinning/Incorrectly:
  • Ensure ESC is properly connected to the flight controller.
  • Calibrate ESCs and check motor direction in the configurator.
  • Verify motor protocol (DSHOT300/600) is correctly set.
  • Check for damaged motor wires or motor itself.
• No Receiver Signal:
  • Confirm receiver is powered and bound to your radio.
  • Check receiver wiring to the flight controller (TX/RX, 5V, GND).
  • Verify UART settings and receiver protocol (e.g., SBUS, Crossfire, ELRS) in the flight controller configurator.
• OSD Issues:
  • Ensure camera and VTX are correctly wired to the OSD pads.
  • Check OSD settings in the flight controller configurator.
• Unstable Flight:
  • Review PID tuning settings.
  • Check for vibrations; ensure the flight controller is properly soft-mounted using silicone absorbers.
  • Verify gyroscope calibration.

9. User Tips

• Solder Carefully: The large solder pads are designed for ease of use, but always use appropriate soldering techniques to avoid bridges or cold joints.
• Power Filtering: While the ESC includes an electrolytic capacitor, consider adding an additional low ESR capacitor at the main battery input for cleaner power, especially with high-power setups.
• Soft Mounting: Always use the provided silicone vibration absorbers for mounting the flight controller to minimize noise to the gyroscope, which can improve flight performance.
• Firmware Compatibility: When updating firmware, always double-check the specific target name for your F722 Flight Controller (DAKEFPVF722 for Betaflight) to prevent bricking the device.

10. Warranty and Support

For technical support, troubleshooting assistance, or warranty inquiries, please contact your retailer or the manufacturer directly. Keep your proof of purchase for any warranty claims. Always refer to the official product page or manufacturer's website for the most up-to-date information and resources.