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:

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

(N)

N=1

N=2

N=3

N=4

N=6

N=20

N=∝

Meaning

One Blink

Two Blinks

Three Blinks

Four Blinks

Six Blinks

Twenty Blinks

Continuous

Blinks

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

Please adhere to “1.1.1 Mixer Type Supported” to choose a mixer type and assemble your aircraft.
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:

M1~M8 are used to connect to the ESCs of the aircraft.
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.
CAN1 and CAN2 ports are working independently and should connect to different modules.
4 independent and configurable outputs.
It is compatible with the external Receiver, e.g. DSM2 satellite Receiver.
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.

Control Mode

GPS ATTI. Mode

ATTI. Mode

Manual Mode

Command Linearity

YES

Yaw

Control the aircraft to rotate in clockwise and counter clockwise direction. Maximum rudder

angular velocity 150°/s

Roll and Pitch

Aircraft attitude control; Mid pointof stick is for 0˚ attitude,

and its endpoint is 35˚.

Max-angular velocity is 150°/s.

No attitude angle limit.

Throttle

Aircraft height control. Maintain the altitude best above 1

meter fromground when the throttle stick is in mid position.

No altitude locking when the

throttle stick is in mid position.

All Sticks

Released

Lock position if GPS signal is

adequate.

Only attitude stabilizing.

No position locking.

Keep original attitude.

GPS Lost

Once GPS signal lost the flight control system will enter ATTI. Mode automatically. Return to GPS ATT1. Mode after GPSsignal

has recovered for 2 seconds.

---

IOC Supported

CL/HL/POI/BTM

None

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.

Control Mode Switch

position-1

position-2

position-3

Configurable

Control Mode

GPS ATTI. Mode

ATTI. Mode *

Manual Mode

FailSafe Protection

The flight control systemwill enter FailSafe Mode if the Transmitter signalis lost and nomatter if Transmitter signal recovers or not,

system will not exit FailSafe mode automatically.

The flight control system will enter FailSafe Mode if the Transmitter signal is lost and the systemwillexit FailSafe once

the signal recovers.

GPS Involved

YES

Low-voltage Protection

LED alertwith Descending or Go Home & Landing precautions

Only LED alert

Environment recommended

Open flying field; Good GPSsignal

Narrow Space; GPS signal bad

Regain control in emergency

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

Before use of the product, please accept some flight training (Using a simulator to practice flying, getting instruction from a professional person, etc.).
DO NOT fly in bad weather, such as rain or wind (more than moderate breeze) or fog.
The flying field should be open without tall buildings or other obstacles; the buildings of steel structure will interfere with the compass.
Keep the aircraft away from obstacles, crowds, power lines, trees, lakes and rivers etc.
Try to avoid interference between the remote control Transmitter and other wireless equipment.(No base station or cell tower around)
The flight control system can’t work at the South Pole and the North Pole.
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

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

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

WARNING

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

Power on and Check

Control mode LED indicator

Control Mode LED indicator

ControlMode

Switch

GPS ATTI. Mode

ATTI. Mode

Manual Mode

LED

(Stick not in midpoint (2))

(Stick not in midpoint (2)

No LED indicator

Set

Put the Control Mode switchto GPS position for basic flyingtest.

Note: whenthe GPS signalLED indicator is bad or worst ((2) or (3)) and lasts formore than 3secs, the flight controlsystem will enterinto ATTI. Mode.

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

GPS signalLED indicator
Worst (< 5)： (3)	Bad (= 5)： (2)	Well (= 6)： (1)	Best (> 6)：No indicator

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:

The throttle sticks is under 10% for more than 3secs after motors start.
The throttle sticks is under 10% for more than 3secs after landing.
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.

The Controller Unit fails to obtain the firmware version of IMU and GPS, please check the connection or upgrade the IMU and GPS.
The firmware version of IMU and Controller Unit is mismatched; please upgrade the firmware of IMU or Controller Unit.
The firmware version of GPS and Controller Unit is mismatched; please upgrade the firmware of GPS or Controller Unit.
The transmitter calibration has exited abnormally, please recalibrate.
The transmitter calibration results with big bias, please recalibrate.
The transmitter calibration results with big mid point bias, please recalibrate.
Incorrect channel mappings, please make sure the basic channels A/E/T/R/U are mapped correctly
Invalid SN or SN error; please contact your dealer or DJI custom service.
The Controller Unit is locked, please unlock the Controller Unit and reconfigure all the parameters in the Assistant software.
IMU disconnected, please check the connection.
Compass data abnormal, please eliminate magnetic interference and recalibrate the compass.
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.
The attitude status is bad and the LED indicator blinks white, the motors will fail to spool up
The Transmitter disconnected, the motors will fail to spool up.
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.

1. Waitthe GPS signal to be well

LED

Place the aircraft away from you and others at least 3 meters and wait the ≥6 (about 36 seconds).

or no Red LED

2. Start motorsand takeoff aircraft.

LED

Execute CSC to startmotors; all sticksback to midpoint as soon as motors start,then push the throttle stick to take off the aircraft, meanwhile the home pointis recorded. NOTE:

36secs after poweron; 10secs after ≥6; Motors havebeen started, auto-record the

position as home point at the firsttime the throttle stick is raised

(∝)

After the home pointis recorded successfully and the distance from aircraft is lessthan 8m, LED indicatorwill blink 5 violet continually. Note: only when GPS signal is good (no Red

LED) LED indicator will blink 5 violet continually.

(5)

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

4.Hover

In GPS ATTI. Mode，the aircraft will hover when the throttle/yaw/roll/pitch sticks are all released at mid-point.

5.Landing

Use the throttle stick to control the landing speed, try to land youraircraft gently to avoid shock or crash.

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

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

PMU connection status detection:

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.
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

Basic Channels	Default Settings	Usage Descriptions
A	Roll Control of the Controller Unit, mapped to the Channel 1 of Receiver	During Assistant Software usage, please click the “Calibration” button, to calibrate the Transmitter sticks travel.During calibrating, make sure to operate strictly following the prompts; otherwise may lead to calibration failure. Click the “Map” button, then you can re-do mapping for A/E/T/R/U.
E	Pitch Control of the Controller Unit, mapped to the Channel2 of Receiver
T	Throttle Control of the Controller Unit, mapped to the Channel3 of Receiver
R	Yaw Control of the Controller Unit, mapped to the Channel4 of Receiver
U	Control Mode Switchof the Controller Unit, mapped to the Channel7 of Receiver
Knob Channels	Default Settings	Usage Descriptions
K1~K6	Remote Gains Adjustment of the Controller Unit, unmapped.	Click “Unmapped” button to map K1~K6to the channels of Receiver.
Direct Channels	Default Settings	Usage Descriptions
D1~D4	Direct Channels (The corresponding ports are F1~F4 on the Controller Unit) of Controller Unit, unmapped.	Click “Unmapped” button to map D1~D4 to the Receiver channels. If you enable the Gimbal functions in Assistant Software, then the F3/F2 are usedfor gimbal control; even D3/D2 are mapped to channels of Receiver, and the signals from the mappedReceiver

		channels will be ignored. You can use F4 for switching the video channel of iOSD Mark II, then map D4 to a Receiver channel.
Advanced Channels	Default Settings	Usage Descriptions
IOC	IOC function of the Controller Unit, unmapped.	Click “Unmapped” buttonto map IOC to a Receiver channel. It is recommended to use a 3-position switch channel.
Go Home	One-Key Go Home function of the Controller Unit, unmapped.	Click “Unmapped” button to map Go Home to the Receiver channel. It is recommended to use a 2-position switch channel.
Gear	Intelligent Gear function of the Controller Unit, unmapped.	If you enable the Gear function in Assistant Software, then the F1 is used for the gear control of S800 EVO landing.
H-Fence(Home Fence)	Home Fence function unmapped	Click “Unmapped” button to map Home Fence onto the Receiver channel. It is recommended to use a 2-position switch channel.
CC (Cruise Control)	Cruise Control function unmapped	Click “Unmapped” button to map Cruise Control to the Receiver channel. It is recommended to use a 3-position switch channel.
S-Gimbal	Ground station servogimbal function unmapped	Click “Unmapped” button to map Ground station servo gimbal to the Receiver channel.It is recommended to use a 3-position switch channel.
Zenmuse Channels	Default Settings	Usage Descriptions
ROLL	ROLL channel unmapped	Click “Unmapped” button to map ROLL to the Receiver channel. It is recommended to use a level switch channel.
TILT	TILT channel unmapped	Click “Unmapped” buttonto map TILTto the Receiver channel. It is recommended to use a level switch channel.

PAN	PAN channel unmapped	Click “Unmapped” buttonto map PAN to the Receiver channel. It is recommended to use a level switch channel.
MODE	MODE channel unmapped	Click “Unmapped” buttonto map MODE to the Receiver channel. It is recommended to use a 3-position switchchannel.
SHUT	SHUT channel unmapped	Click “Unmapped” button to map SHUT to the Receiver channel. It is recommended to use a 2-Position switch withspring back function.
AUX1	AUX1 channel unmapped	Click “Unmapped” button to map AUX1 to the Receiver channel. It is recommended to use a 3-position switch channel.
AUX2	AUX2 channel unmapped	Click “Unmapped” button to map AUX2 to the Receiver channel. It is recommended to use a 2-position switch channel.
AUX3	AUX3channel unmapped	Click “Unmapped” buttonto map AUX3 to the Receiver channel. It is recommended to use a 2-position switch channel.

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

Controller Unit Channel	Receiver Channel	Recommended Transmitter Switch
A	Channe 1 (AIL)	Joystick J1
E	Channe 2 (ELE)	Joystick J2
T	Channe 3 (THR)	Joystick J3
R	Channe 4 (RUD)	Joystick J4
U	Channe 7 (AUX5)	3-Position switch, e.g. SG
K1~K6	Channe 5 (GEAR)	Knob switch, e.g. LD, RD
Pitch	Channe 6 (Vpp)*	Knob switch, e.g. LD, RD
D1/D3/D2	----	----
D4	Channe 9 (AUX1)	2-Position switch, e.g. SF
IOC	Channe 10 (AUX2)	3-Position switch, e.g. SG
Go Home	Channe 11 (AUX3)	2-Position switch with spring back function, e.g. SH
Gear	Channe 8 (AUX4)	2-Position switch, e.g. SF

H3-2D	Channe 12（AUX5）*	Knob switch, e.g. LD、RD
H-Fence	Channe 6 (Vpp)*	2-Position switch, e.g. SF
CC	Channe 12（AUX5）*	3-Position switch, e.g. SB

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

Controller Unit Channel	Receiver Channel	Recommended Transmitter Switch
A	Channe 1 (AIL)	Joystick J1
E	Channe 2 (ELE)	Joystick J2
T	Channe 3 (THR)	Joystick J3
R	Channe 4 (RUD)	Joystick J4
U	Channe 7 (AUX5)	3-Position switch, e.g. SG
IOC/CC	Channe 8 (AUX4)	3-Position switch, e.g. SA
Gear	Channe 9 (AUX6)	2-Position switch, e.g. SF
PAN	Channe 5 (GEAR)	Level switch, e.g. LS、RS
TILT	Channe 6 (Vpp)	Level switch, e.g. LS、RS
MODE	Channe 10 (AUX1)	3-Position switch, e.g. SC
Photo	Channe 11 (AUX2)	2-Position switch with spring back function, e.g. SH
Video	Channe 12 (AUX3)	3-Position switch, e.g. SG

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

Controller Unit Channel	Receiver Channel	Recommended Transmitter Switch
A	Channe 1 (AIL)	Joystick J1
E	Channe 2 (ELE)	Joystick J2
T	Channe 3 (THR)	Joystick J3
R	Channe 4 (RUD)	Joystick J4
U	Channe 7 (AUX5)	3-Position switch, e.g. SG
IOC	Channe 8 (AUX4)	3-Position switch, e.g. SA
CC	Channe 9 (AUX6)	2-Position switch, e.g. SF
Gear	DG1	2-Position switch, e.g. SF
ROLL	Channe 10 (AUX1)	Knob switch, e.g. LD、RD
PAN	Channe 5 (GEAR)	Level switch, e.g. LS、RS
TILT	Channe 6 (Vpp)	Level switch, e.g. LS、RS

MODE	Channe 11 (AUX2)	3-Position switch, e.g. SC
Photo	DG2	2-Position switch with spring back function, e.g. SH
Video	Channe 12 (AUX3)	3-Position switch, e.g. SG

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

Controller Unit Channel	Receiver Channel	Recommended Transmitter Switch
A	A	Master remote control J1
E	E	Master remote control J2
T	T	Master remote control J3
R	R	Master remote control J4
U	U	Master remote control S1
Gear	X2	Master remote control S2
ROLL	A	Slave remote control J1
PAN	E	Slave remote control J2
TILT	R	Slave remote control J4
MODE	U	Slave remote control S1
Photo	X1	Slave remote control LD
Video	X2	Slave remote control S2

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

Run the A2 Assistant and go to the Channel Mapping page.
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.

Aircraft	Configuration Information					Basic			Attitude
Aircraft	Motor	ESC	Propeller	Battery	Weight	Pitch	Roll	Yaw	Pitch	Roll	Vertical
F450	DJI-2212	DJI-30A	DJI-8 Inch	3S-2200	890 g	150	150	135	150	150	140
F550	DJI-2212	DJI-30A	DJI-8 Inch	4S-3300	1530 g	170	170	150	160	160	150
S800 EVO/Z15	DJI-4114	DJI-40A	DJI-15Inch	6S-15000	7000g	140	140	130	140	140	130

S1000/5D gimbal/

5D camera

DJI-4114

DJI-40A

DJI-15Inch

6S-15000

9200g

120

170

120

S1000/5D gimbal/

5D camera

DJI-4114

DJI-40A

DJI-15Inch

6S-15000

9300g

120

170

120

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)

Transmitter type	AREA	FASST
FUTABA 18MZ	Default	FASST-MULTI\FASST-7CH
FUTABA 14MZ with TM-14	Default	MULT\7CH
FUTABA 14SG	FRANCE\GENERAL	FASST-MULTI\FASST-7CH
FUTABA 12Z 2.4G FASST with TM-14	Default	MULT\7CH
FUTABA 12FG 2.4G FASST with TM-14	Default	MULT\7CH
FUTABA 10CG or 10C with TM-10	Default	7CH
FUTABA 9C SUPER with TM-7 or TM-8	Default	7CH
FUTABA 8FG SUPER	FRANCE\GENERAL	MLT2\MULT\7CH
FUTABA 8FG	FRANCE\GENERAL	MULT/7CH
FUTABA 7C 2.4G	Default	Default
FUTABA 6EX FASST	Default	Default

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.

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