NeutronRC AT32F435 Mini 2S AIO Flight Controller User Manual

1. Introduction

The NeutronRC AT32F435 Mini 2S AIO is an advanced All-In-One (AIO) flight controller designed for FPV drones, integrating a powerful AT32F435 microcontroller, a 32-bit AM32/HF32 ESC, and an ELRS 2.4G receiver. This compact board features a 25.5x25.5mm mounting pattern, making it ideal for micro and lightweight builds. This manual provides detailed instructions for setup, configuration, and operation to ensure optimal performance and a safe flying experience.

Figure 1: Front view of the NeutronRC AT32F435 Mini AIO Flight Controller

2. Key Features

The AT32F435 Mini 2S AIO Flight Controller boasts a range of features for high-performance FPV applications:

• MCU: AT32F435CGU7 (288MHz, 1MB Flash)
• IMU: BMI270 (SPI1) for precise flight control
• OSD: AT7456E (SPI2) for on-screen display
• Blackbox: 16MB SPI Flash for flight logging
• Barometer: Infineon DPS310 (I2C1)
• UARTs: 5 available (UART1, UART2, UART3, UART4, UART7)
• BEC: 5V 2.0A and 12V 2.0A
• ESC: 32-bit AM32/HF32 (AT32F421) supporting 1-2S 12A or 2-3S 20A configurations
• Receiver: Integrated ELRS 2.4G (DIY 2400 RX ESP8285 SX1280)
• LEDs: 4x LEDs for FC Status, 3.3V, 5V, and ELRS indication
• Mounting: 25.5x25.5mm
• PCB: 8-layer design for enhanced durability and performance
• Connectivity: Micro USB port
• Antenna: IPX-1 Antenna connector for ELRS

Figure 2: NeutronRC AT32F435 Mini AIO 2S Features and Pinout Diagram

3. Specifications

4. Package Contents

Upon opening your package, you should find the following items:

• NeutronRC AT32F435 Mini 2S AIO Flight Controller Board
• XT30 Connector with pre-soldered power wires
• ELRS Antenna
• Electrolytic Capacitor
• Silicone Grommets (for mounting)
• Wiring Harness (various wires for connections)

Figure 3: Included components in the package

5. Setup and Configuration

5.1 Driver Installation

Before connecting your flight controller, ensure all necessary drivers are installed. This is crucial for proper communication with configuration software.

• COM Driver for Betaflight Configurator: Download and install the driver for the AT32 series flight controllers. This enables the flight controller to be recognized as a COM port.
  Download COM Driver
• DFU Driver for Firmware Update: This driver is required for flashing new firmware to the flight controller in Device Firmware Upgrade (DFU) mode.
  Download DFU Driver
• Artery USB Driver: For specific Artery MCU communication.
  Download Artery USB Driver

5.2 Betaflight Configurator Setup

To connect and configure your flight controller using Betaflight Configurator (version 10.9 or later is recommended):

1. Open Betaflight Configurator.
2. Navigate to the 'Options' tab.
3. Enable the option "Show all serial devices (for manufacturers or development)" to ensure your AT32-based flight controller is detected.

Figure 4: Enabling 'Show all serial devices' in Betaflight Configurator

Default Port Configuration

The default UART settings are typically configured as shown below. Verify these settings in the 'Ports' tab of Betaflight Configurator.

Figure 5: Default UART Port Configuration

Blackbox Configuration

To activate mass storage device mode for blackbox data, navigate to the 'Blackbox' tab and select the option to activate Mass Storage Device Mode. This allows you to access flight logs directly from your computer.

Figure 6: Blackbox Configuration and Mass Storage Mode

Initial Settings (After Firmware Update)

After updating firmware, it is recommended to review and set the following options for initial setup:

• Board and Sensor Alignment: Configure Roll, Pitch, and Yaw degrees as needed.
• Voltage Meter: Calibrate the voltage scale and divider values.
• Amperage Meter: Calibrate the amperage scale and offset values.

Figure 7: Initial Settings in Betaflight Configurator

5.3 Firmware Information and Updates

The flight controller supports various firmware options. Always refer to the latest documentation for specific flashing procedures.

• Flight Controller (FC) Firmware:
  • The default FC firmware is ATbetaflight 4.3.2-RC4. This is a special branch of Betaflight optimized for non-ST MCUs like the AT32F435, offering lower cost and improved BMI270 driver support for better flight stability.
  • The current Betaflight 4.4.X version does not support the AT32F435 chip. Betaflight 4.5 is expected to include support for the AT32F435 chip in the future.
  • Latest ATbetaflight firmware releases can be found here: ATbetaflight Releases
• ELRS Firmware:
  • The default ELRS firmware is version 3.2.1.
  • The default ELRS binding phrase/password is: neutronrc
  • To update ELRS firmware, use the ExpressLRS Configurator. Select the appropriate target, such as 'EMAX 2.4GHz RX' for compatible receivers.
  

  Figure 8: ExpressLRS Configurator Target Selection
• ESC Firmware (AM32/HF32):
  • The ESC comes pre-flashed with either AM32 or HF32 firmware, depending on the variant.
  • For AM32 ESC configuration, a known bug exists in the standard AM32 website configurator which can cause malfunctions. It is recommended to use the development version web configurator: AM32 ESC Development Configurator
  • For HF32 ESC configuration, use the dedicated HF32 ESC Configurator: HF32 ESC Configurator
  • When updating AM32 firmware, select the appropriate target, for example, 'AM32_NEUTRON_1_2S_AIO_F421'.
  

  Figure 9: AM32 Configurator Firmware Selection

• Quicksilver Firmware:
  • The flight controller perfectly supports Quicksilver firmware, which is known for excellent performance on small frames with protective ducts.
  • Quicksilver Configurator: Quicksilver Configurator
  

  Figure 10: Quicksilver Configurator Flash Interface

• Detailed Firmware Update Guide: For comprehensive instructions on updating both FC and ESC firmware, please refer to the following document: AT32F435 Mini AIO Firmware and ESC Upgrade Guide

5.4 Wiring Diagram

Refer to the following diagram for connecting your flight controller to other components, including motors, receiver, and video transmission system. This diagram illustrates a typical setup for a DJI digital image transmission system.

Figure 11: Default Wiring Diagram for DJI Digital Image Transmission System

5.5 Motor Compatibility

The following table provides guidance on motor compatibility with the 1-2S 12A and 2-3S 20A ESC variants. 'Y' indicates tested and compatible, 'Caution' indicates not fully tested but potentially compatible, and 'N' indicates absolutely prohibited.

Figure 12: Motor Compatibility Chart

6. Operating Instructions

Once the flight controller is correctly wired and configured:

1. Power On: Connect a compatible 1S-3S LiPo battery to the XT30 connector. Observe the LED indicators for proper initialization.
2. Radio Binding: Ensure your ELRS radio transmitter is bound to the integrated ELRS receiver. Refer to your ELRS module's manual for binding procedures, using the default password 'neutronrc' if prompted.
3. Pre-Flight Checks: Before each flight, perform a visual inspection of all connections. Verify motor direction and responsiveness in Betaflight Configurator's 'Motors' tab (with propellers removed for safety). Check flight modes and arming switch functionality.
4. First Flight: For initial flights, choose an open area away from obstacles. Start with gentle maneuvers to assess flight characteristics and make any necessary PID adjustments.
5. Blackbox Analysis: After flights, you can download blackbox logs (via Mass Storage Mode) to analyze flight performance and troubleshoot issues.

7. Maintenance

• Regular Inspection: Periodically inspect the board for any signs of physical damage, loose connections, or solder joint issues.
• Cleaning: Keep the flight controller clean from dust, dirt, and debris. Use a soft brush or compressed air. Avoid using liquids directly on the board.
• Firmware Updates: Stay updated with the latest stable firmware versions for both the FC and ESC to benefit from performance improvements and bug fixes.
• Storage: When not in use, store the flight controller in a dry, anti-static environment.

8. Troubleshooting

• Flight Controller Not Connecting to Betaflight:
  • Ensure all necessary drivers (COM, DFU, Artery USB) are correctly installed.
  • Verify that "Show all serial devices" is enabled in Betaflight Configurator options.
  • Try a different USB cable or USB port on your computer.
• ESC Malfunctions After Configuration (AM32):
  • There is a known bug in the standard AM32 website configurator. Use the development version web configurator for AM32 ESC configuration to avoid issues.
• Flight Controller Not Responding / Unstable Flight:
  • Check all wiring connections for continuity and correct polarity.
  • Ensure the correct FC firmware (ATbetaflight 4.3.2-RC4 or later compatible version) is flashed. Betaflight 4.4.X does not support AT32F435.
  • Perform sensor calibration (accelerometer, gyroscope) in Betaflight Configurator.
  • Review PID settings; start with default or recommended values for your frame size.
• ELRS Receiver Issues:
  • Confirm the ELRS module in your radio is on the same major version as the receiver firmware (e.g., both 3.x.x).
  • Re-bind the receiver to your radio transmitter using the correct binding phrase.
  • Check antenna connection.
• AM32 Hardware Compatibility Issues:
  • NeutronRC is actively working with AM32 authors to improve compatibility. If you encounter software-related issues with AM32, please consider this ongoing development.

9. User Tips

• Understanding ATF & HF Variants: The product offers different variants like "ATF HF32 1-2S 12A", "ATF HF32 2-3S 20A", "BF AM32 1-2S 12A", and "BF AM32 2-3S 20A".
  • "ATF" typically refers to the ATbetaflight firmware running on the Flight Controller.
  • "BF" refers to standard Betaflight firmware running on the Flight Controller.
  • "HF32" and "AM32" refer to the specific 32-bit ESC firmware used. These ESC firmwares have different features and configurators.
  • The "1-2S 12A" and "2-3S 20A" indicate the supported battery voltage range and continuous current rating of the integrated ESCs. Choose the variant that matches your motor and battery setup.
• Propeller Safety: Always remove propellers when connecting the flight controller to your computer or performing any configuration/testing.
• Solder Quality: Ensure all solder joints are clean and strong to prevent intermittent issues or component failure.

10. Warranty and Support

For any technical assistance, warranty claims, or support inquiries, please contact the NeutronRC Store directly through the platform where you purchased the product. Provide your order details and a clear description of the issue to facilitate a quick resolution.