DJI A2 Flight control system Introduction 

The DJI A2 Multi-Rotor stabilization controller is a complete flight system for various multi-rotor platforms for commercial and industrial aerial photography. Based on the technology and design philosophy of DJI’s Ace series of high-performance controllers, the A2 offers you a brand new flight experience. Its flight mode provides a seamless transition for current Ace One, WKM AP professionals. A2 features includes: 

1. Integrated with high-precision sensor components and a high-performance GPS Receiver.
2. Utilizes high quality components precisely calibrated with temperature compensation in all gyros and sensors, industry renowned flight algorithm in autopilot and UAV field.
3. Designed with built-in vibration absorption, no extra mount frame or vibration absorption pad is required.
4. Provide high precision control and high performance handling experience.
5. Based on the DESST technology, it has a built-in 16-channel Receiver, and supports DSM2 satellite receiver.
6. Optional DJI D-BUS Adapter can be used with a traditional Receiver.

In the Box 

Equipment Prepared by Users 

Detailed Specifications

The DJI A2 Flight Control System features a built-in IMU and barometer for precise hovering and flight stability. It has a maximum flight speed of 58 mph (93 km/h) and a maximum flight altitude of 16,404 feet (5,000 meters). It supports a wide range of GPS satellites for accurate positioning and has a built-in DJI Lightbridge system for long-range transmission.

System Introduction 

The A2 flight control system uses the Controller Unit at its core, which is connected with the IMU,  GPS-COMPASS PRO PLUS、LED-BT-I、PMU and ESCs to complete the system. The system can achieve the height-lock and position-lock functions by using the IMU and the GPS, to control the aircraft. 

Please carry out the following procedures to finish assembly, configuration and flight-testing. 

General Symbol 

LED Symbol 

Example: (3) means three Red blinks. 

(∝)LED blinks yellow and green alternatively.

(N)	N=∝
Meaning	Continuous Solid on

Example: (∝) means Continuous Blue Solid on. 

Assembly and Configuration 

For hardware installation, software configuration and compass calibration please adhere to the following sections. 

Hardware Installation and Connection 

1. Please adhere to “1.1.1 Mixer Type Supported” to choose a mixer type and assemble your aircraft.
2. Please adhere to both “1.1.2 Hardware Connection Diagram” and “1.1.3 Important for Assembly and Connection” to install and connect all units on your aircraft.

Mixer Type Supported 

The following Mixer Types are supported. 

WARNING: The direction of the arrow in diagram indicates the rotation direction of the motor/propeller. For coaxial propellers: Blue propeller is at TOP; Red propeller is at Bottom. Otherwise all propellers are at top. 

Hardware Connection Diagram

Important for Assembly and Connection

This section describes all device port functions, assembly requirements, connection requirements and tips during usage. Also the linking procedures between the built-in Receiver DR16 and your Transmitter. Please read all information below carefully, especially if you are a first time user. 

Controller Unit

The Controller Unit is the core component of the A2 flight control system: 

1. M1~M8 are used to connect to the ESCs of the aircraft.
2. The built-in Receiver DR16 is based on DJI DESST technology, which can be used with the Futaba FASST series and DJI DESST series Transmitter. 
3. CAN1 and CAN2 ports are working independently and should connect to different modules.
4. 4 independent and configurable outputs.
5. It is compatible with the external Receiver, e.g. DSM2 satellite Receiver.
6. Use the optional DJI DBUS Adapter to support the traditional receiver.

Description

The DJI A2 Flight Control System is a compact and easy-to-use flight control solution that offers professional-grade features and performance. It supports various flight modes, including GPS, Attitude, and Manual, allowing users to choose the mode that best suits their needs. The built-in DJI Lightbridge system enables long-range transmission, making it ideal for aerial photography and industrial applications.

Basic flying 

Control Mode Instruction 

The aircraft performs differently when using different control modes. Please read the following table to know the different control modes, which may help you to achieve a more involved flight experience. 

Assign a 3-position switch of the transmitter as the control mode switch. The position-1 is defaulted as “GPS ATTI. Mode” and the position-2 is “ATTI. Mode”. The position-3 can be set as “Manual Mode” or “ATTI. Mode” in A2 assistant software. 

The difference between ATTI. Mode of position-2 and ATTI. Mode of position-3 is that they are working differently in protection situations. 

Flying Environment Requirements 

WARNING

1. Before use of the product, please accept some flight training (Using a simulator to practice flying, getting instruction from a professional person, etc.).
2. DO NOT fly in bad weather, such as rain or wind (more than moderate breeze) or fog. 
3. The flying field should be open without tall buildings or other obstacles; the buildings of steel structure will interfere with the compass. 
4. Keep the aircraft away from obstacles, crowds, power lines, trees, lakes and rivers etc.
5. Try to avoid interference between the remote control Transmitter and other wireless equipment.(No base station or cell tower around) 
6. The flight control system can’t work at the South Pole and the North Pole.
7. All parts must be kept out of the reach of children to avoid CHOKE HAZARD; if a child accidentally swallows any part you should immediately seek medical assistance.

Check List before Flying 

Double-check the following list, otherwise, if any one of the following items is wrong it may lead to flight accident. 

CAUTION

1. All parts are in good condition, no ageing or damaged components
2. Motor rotating direction
3. Propeller mounting direction
4. Mixer Type set in assistant software
5. IMU and GPS-COMPASS PRO PLUS mounting direction
6. Transmitter channel mapping and sticks movement direction correct
7. Compass calibration
8. ESC connection
9. IMU and GPS-COMPASS PRO PLUS firmly mounted

In addition, check the following items to make sure the system can work. 

WARNING

1. The Transmitter battery is fully charged.
2. The aircraft battery is fully charged.
3. Do not overload the aircraft.

Power on and Check 

Control mode LED indicator 

GPS signal LED indicator
GPS signal indication blinks after every Control mode indication. We suggest flying when GPS satellites are more than 5. 

Start Motors Methods 

CSC (Combination sticks commands) is used to start motors instead of just pushing the throttle stick. One of the following methods can be used to start/stop motors. 

Under the conditions stated below, the motors will stop in ATTI. Mode/GPS ATTI. Mode: 

1. The throttle sticks is under 10% for more than 3secs after motors start.
2. The throttle sticks is under 10% for more than 3secs after landing.
3. The throttle sticks is under 10% for more than 3secs and the inclined angle of aircraft exceeds 70°。

If motors fail to start, please refer to the following list for trouble shooting. 

1. The Controller Unit fails to obtain the firmware version of IMU and GPS, please check the  connection or upgrade the IMU and GPS.
2. The firmware version of IMU and Controller Unit is mismatched; please upgrade the firmware of IMU or Controller Unit. 
3. The firmware version of GPS and Controller Unit is mismatched; please upgrade the firmware of GPS or Controller Unit. 
4. The transmitter calibration has exited abnormally, please recalibrate.
5. The transmitter calibration results with big bias, please recalibrate.
6. The transmitter calibration results with big mid point bias, please recalibrate.
7. Incorrect channel mappings, please make sure the basic channels A/E/T/R/U are mapped correctly
8. Invalid SN or SN error; please contact your dealer or DJI custom service.
9. The Controller Unit is locked, please unlock the Controller Unit and reconfigure all the parameters in the Assistant software.
10. IMU disconnected, please check the connection. 
11. Compass data abnormal, please eliminate magnetic interference and recalibrate the compass.
12. When Flight limit function is enabled, if the aircraft fly out of the max-radius in ATTI. mode and the motors are stalling, the motors will fail to spool up in GPS ATTI. mode cause the Flight limit function works. 
13. The attitude status is bad and the LED indicator blinks white, the motors will fail to spool up
14. The Transmitter disconnected, the motors will fail to spool up.
15. The A2 flight control system is connecting and communicating with the Assistant software, the motors will fail to spool up. 

Basic Flying Test 

Carry out the following procedures to complete the basic flight test.

Operate sticks to control the flying attitude of the aircraft during flight

Please refer to the next section “Protection Functions Setting” to take precautions. 

1. Low voltage alert: yellow quick flashes or red quick flashes. 
2. FailSafe: LED indicator blinks blue.
   Moreover, you may come across the following abnormal situation, please carry out the operation below. 
3. Compass data is abnormal; the LED blinks yellow and green alternatively. Please re-calibrate the Compass.
4. IMU data is abnormal, the LED blinks four green. Please contact your dealer.

PMU connection status detection: 

1. If detected before takeoff, the motors will not start and takeoff is inhibited. The LED module will continuously flash red four times. To resume normal flight, ensure that the PMU is connected correctly.
2. If detected during flight, the LED module will continuously flash red four times, at which point you should land the aircraft and re-connect the PMU to resume the battery voltage readings and low voltage protection.

GPS SNR Functions Description 

The DJI A2 Assistant (version 1.1.22) and iPad ground station (version 1.4.62) have recently added “SNR Health” and “SNR Fluctuation” index monitors for GPS signals. Users can monitor GPS signal quality, ensuring they have strong and stable signals for better flight performance. By referring to these two values, the user will be empowered to find the best locations for take-off and flight, while also detecting areas that might interfere with GPS signals. 
The SNR interface provides you with “SNR Health” and “SNR Fluctuation” index monitors whose values change according to aircraft maneuvers and environmental interference. 

• The “SNR Health Index” shows the GPS signal strength captured by the GPS receiver. A larger number indicates a stronger GPS signal. We highly recommend pilots only take off when the SNR health value is greater than 36.

• The “SNR Fluctuation Index” shows the overall stability of the craft’s current GPS signal. A smaller number means that the signals will fluctuate less and provide a more stable GPS signal overall.

  

  

A2 Receiver Type Description 

• For different types of receivers, displays on the A2 Assistant software will be different. For PPM receivers with Failsafe, the display is as below: 

  

• For the other receivers, the display is as below: 

  

For example, when used with DJI Lightbridge, you will see the second display after disconnecting the remote controller and Lightbridge. At this time, the A2 LED will blink blue and the aircraft will enter Failsafe. 

Channel Mapping Instructions for PC Assistant Software 

Recommended Mapping for Futaba RC (Mode 2, A2 V2.4 or below) 

Recommended Mapping for Futaba RC (Mode 2, A2 V2.5 and Futaba below V5.0) 

Recommended Mapping for Futaba RC (Mode 2, A2 V2.5 and Futaba V5.0) 

Recommended Mapping for DJI NDJ6 RC (A2 V2.5) 

Note that these settings should be configured according to your requirements. Follow the steps below to check if the channels are working properly: 

1. Run the A2 Assistant and go to the Channel Mapping page.
2. Move the Master remote controller’s sticks and switches to ensure they are working properly on the Channel Mapping page.

Note: For the H3-3D gimbal, set a 2-position switch with spring back function for the TILT channel and a 2-position switch for the MODE channel. 

Settings of gain values for Your Reference 
To set the value of basic gain and attitude gain you can refer to the following diagram. These values are only for  reference and may vary in practice. 

The Transmitter setup of FUTABA 

Please configure the Frequency item on your Transmitter adhere to the table below. (The names of FASST modes here are based to the Transmitter FUTABA T8FG, please ensure to select the most similar mode as the names differs for different Transmitters)

Troubleshooting

• If you encounter any issues with your DJI A2 Flight Control System, there are a few common solutions to try. 
• First, check to ensure that all cables and connections are securely fastened. 
• If the issue persists, try resetting the system to its factory settings. 
• If you are still experiencing problems, contact DJI's customer support for further assistance.

Pros & Cons

Pros

• Professional-grade features and performance
• Supports a wide range of flight modes
• Long-range transmission capabilities
• Easy to use and set up

Cons

• Expensive compared to other flight control systems
• May be overkill for casual users

Customer Reviews

Overall, customers have been impressed with the performance and features of the DJI A2 Flight Control System. Many have praised its ease of use and long-range transmission capabilities, while others have noted its professional-grade features and performance. However, some have criticized its high price point, noting that it may be overkill for casual users.