DJI Innovations A2 M FAQ's

What Multi Copter frames can I use the DJI A2 M with?

The DJI A2 M can be used on QuadCopters, HexaCopters, OctoCopter and Y6 mulitcopter frames. There is no support for TriCopters at this time. You can use the A2 M on many airframes including airframes with have a diameter greater than 65 cm’s.

When I arm the A2 M the motors don’t spin up?

Incorrect calibration of the radio is normally the number one concern here; this includes both the “command stick calibration” and all of the flight modes M, Atti, GPS Atti and Fail Safe in the “control mode switch” sections of the “TX Cali” options in the A2 M Assist program. Check that all the functions and movements are as they should be in the “TX Cali” screen.
Incorrect mode selected for flight, if you see a Blue flashing from the LED when you connect your LiPo battery this means you are in Fail Safe mode, select a flight mode like GPS Atti and then try again. If you are unable to change the flight mode to Atti, GPS Atti or Manual mode the LED will not change colour, this is usually caused by the incorrect calibration while setting up the TX system. Please retry the calibration of the RX systems making sure all four corners are reached on both sticks. Be sure to check the trims are set to zero on the radio controller before ding the calibration process, if this is not done the calibration will not be done correctly, if the trim are knocked after the calibration process, this will change the value on the radio and prevent the motors starting, always check this these when the radio is powered on. The motors will not arm when connected to the computer / UBS cable, they are disarmed for safety at this time.

When I try and take off the frame starts to lift on one corner / side and looks like it will flip over if I power up more, what’s happening here?

The most important steps to take before you start to take off for your first time flight, is to check that you have set each option in the assist software correctly; this includes the correct GPS / Compass position figures and radio calibration etc.
When you are sure that these settings are all correct it is a good idea to carry out a “hand test” of the DJI A2 M AutoPilot system and copter. WARNING, the props are very sharp and if they make contact with any part of your body you will be badly injured, make sure you are clear of the props before arming the motors! The “hand test” is best carried out by two people. When you have a firm hold on the main frame plates (hands well away from the prop rotation area) of your copter arm the motors in Atti mode, bring up the power until the props are spinning and you can feel the copter becoming light in your hands, at this point you will tip the copter left, right, back and forwards, as you move the copter you should feel a resistance to these movement in the opposite direction, if this the case start to move the controls for a direction a little, when you push forward, backwards, left and right you should feel the copter starting to pull in that direction of the stick movement, if the DJI Wookong A2 M AutoPilot system and the copter passes these tests you are ready for your first flight, you are cleared for take-off!
Many people will increase the power for take-off very slowly, this can cause the concerns when one side of the copter starts lifting and looking as if it will flip on take-off. The correct way to lift off is to arm the motors, bring the throttle to 50% in one smooth motion and then continue to about 75% throttle to get clear of the ground. When the copter leaves the ground return the throttle to about 50% or just over and you are now up and flying! If all the settings are correct, the system has locked the home point the aircraft will now be sitting stable in the hover with all sticks at “50% / mid positions”.

I tried the “hand Test” and it did not do what I expected?

When things just don’t feel normal, this is normally due to one of a few things, the wrong flight mode selected, incorrect propeller fitment or incorrect motor rotation (CW when it should be CCW), please check that these are correct and try again. Make sure you are not in GPS Atti or manual mode for the hand test, the use of Atti mode is recommended.

I can’t make my A2 M hold position very well; it will just start to drift away?

Are you in GPS Atti mode? The LED will be flashing a purple pulse about once a second, if you are in another flight mode like Atti (Yellow pulse) it will not hold it position. If there are Red flashes between the purple flashes you might not have enough satellites to allow the A2 M to lock in position, if you see Red flashes please try GPS position hold again when the Red flashes have stopped. The LED is very bright on the A2 M, please take care not to stare at it to closely.
Your GPS / Compass unit might have gotten interference for some reason, or the GPS arrow is not pointing straight forward, please check this is aligned correctly.
Did you wait for all of the GPS Red flashes to stop before take-off? If you did not find enough satellites before taking off this can cause issues. We always recommend that the copter be placed in clear view of the sky, when powering up in GPS Atti mode you will see the red flashes between the purple flashes, these will start at three red flashes then drop to two then one. After the red flashes have stopped you will see that there is a set of White flashes very quickly back to back, once you have seen these on power up of the motor you are ready for flight with the home point recordered correctly.
If you see any slow red flashes while in flight like those seen before taking off the system has lost a number of satellites, this could be due to weather or other factors like buildings or trees; it is not unusual for drift to happen when flying low and the GPS / Compass can’t see a clear view of the sky. All GPS units can be affected by “MultiPathing” see this for more information. Flights under bridges or other structures while in GPS mode can result in a crash, if you are planning these clear sky flights to an under structure flight it is recommended to fly in Atti mode.
Have you set all trims to the mid-point on your transmitter, if they are not please do this and try again as this can also cause a “drift” as the A2 M will think you have moved the stick and holding it in that position.

What’s the hovering accuracy in GPS mode with the A2 M?

Horizontal: ± 2m;Vertical: ± 0.5m subjected to mechanical performance.

What is the maximum wind speed I can fly the A2 M in?

<8m/s (17.9mph / 28.8km/h)

What is the climb rate on the A2 M?

Maximum climbing speed is 6m/s in Atti mode and GPS Atti mode. Speed in manual mode is subjected to mechanical setting and power supply.

Why do I need to setup the compass calibration before I can fly?

The compass is used to allow the system to know which way it is pointing, GPS is not very good at knowing the direction you face when standing still, as the copters are holding position they would yaw without the compass being there to keep them pointing the correct direction, so if the compass thinks that North is closer to South you will have yaw issues. It is very important to setup the compass unit before you fly for the first time, it is also important to set it again if you move a long way from your normal flight field. The compass needs to have the magnetic declination set as it will change as you move around to new locations.

Can I use the GPS unit from the Wookong M WKM on the NAZA, or the NAZA GPS on the A2 M?

No, these are not compatible with one another.

Can I use the A2 M on a traditional Helicopter?

No, the A2 M is for multi rotor craft only.

I need to use an OSD with my A2 M; do DJI have one which will work?

Yes, the iOSD from “DJI” is the OSD (On Screen Display) which will work with the Wookong M, it will link over the CAN network and display all the information needed for FPV flights.

I own a radio system already, can I use this? Or what Radio system should I use with the A2 M?

You can use any number of radio systems with the Wookong M, these include PCM or 2.4GHz and have a minimum of 7 channels with a Failsafe function available on all channels, we always recommend the use of the Futaba radio systems as they have S-Bus, this is an exclusive feature to Futaba RC Radios. The S-Bus system removes all of the wires needed to connect to the A2 M Flight Controller by other systems like Spektrum, these are replaced by one S-Bus wire, this replaces up to 8 wires found on another brand of radio like the Spektrum radios. The key things to look for in a radio system is 2 three position switches and a “knob” which will allow you to do both the initial in-flight tuning, then at a later point this same “knob” can then be used for a camera gimbal to adjust the pitch to look down to the ground while taking photos or filming. If you are using the A2 M with an airframe like the s900 or s1000 and need to be able to use one of the Zenmuse gimbals then using a 14 channel radio would mean that you can controll all the functions from that one radio.

Should I use Aeroplane or Helicopter mode on my radio system with the A2 M?

You should use Aeroplane mode, also know as “ACRO”, please do not use Helicopter mode on your RC radio system.

Where are the Bec / uBec on the system?

The A2 M AutoPilot is supplied with a uBec, this is called a PMU by DJI, and it acts as both the uBec and forms part of the CAN network for communications with the rest of the system.

How do I know when my battery is low in power and I need to land?

When setting up the A2 M in the assist software the voltage section allows you to tell the system what voltages you would like to set on the battery warnings, there is even a calibration section to allow you to fine tune the A2 M battery monitor so you know it will be precise, the Flight Mode LED will flash a rapid yellow or red LED when the battery low voltage settings are reached. This warning will work in all modes.

I can’t get the A2 M to connect with my computer?

You will need to install the USB drivers for your PC to allow Windows to recognise that you are using new hardware and allow it to communicate with it. At this time the A2 M Assist is a PC only application, Mac users need to operate the A2 M Assist in an emulator.

I have seen the A2 M come home and land by itself, is this Fail Safe?

Yes, there are two ways in which you can trigger the fail safe / Return To Home settings, you assign a switch to send the A2 M home or you can set your RC radio to go into fail safe mode if you fly beyond the range of the radio or the signal is lost while in flight. You can set these up to run alongside each other, so you have a choice of flicking a switch to bring home the A2 M or if there was a loss of signal it will do the same. The pre-built kits which we sell are set up with the fail safe on both a switch and on signal loss.

How can I set up fail safe on my system?

If  your radio supports “fail safe” on the transmitter channel used to select the modes, then you can set up fail safe for signal loss, if you don’t have a radio which will do this then you can only have fail safe on a three position switch. The Futaba 14 allows you to do the fail safe settings on the switch and the radio signal loss at the same time.

How do I know fail safe is working? Can I check it before I need it?

Yes, when you have the A2 M connected to the PC and the assist software is running all you will need to do is switch off your radio system, you will see that the “flight mode” will jump to the fail safe option, when this happens the failsafe box will turn blue, if you are not able to set your radio to this function on signal loss you can't set and use this feature, you can still test this by moving the function to a switch for manual switch to the fail safe position, this is normally the Return To Home function, this will have the same outcome, the copter will return to home when the fail safe box is highlighted. When you are happy that all these settings are correct, go to your flight field and test the operation of the fail safe while in flight, the first tests are best done close by to make sure all is working as expected. Please note the A2 M will climb to 20 meters (unless you have changed it to another figure during setup of the return altitude) if it is below this height before returning home to land, this figure will be higher if you have selected another option while setting up the Return to Home feature in the Assist program. If you trigger fail safe in front of you at 3 or 4 meters it will ascend before it comes back to you.

I would like to use PPM, can I?

Yes, PPM is an option on the A2 M.

I have read that you should leave your A2 M outside to acclimatise to a shift in temperature on a cold / hot day, is this true?

With all systems the temperature will have an effect on the gyro’s and accelerometers, it is a good idea to allow a short period of time for the system to adjust to the temperature before flight, a few min’s would be enough to allow for this to take place.

I see an error message flashing in the lower left of the assist software window, what does it mean?

This is normally seen after an update has been done, if you click on the flashing message it will explain why the message is there and the steps needed to stop it from happing, normally this will be a cycle of the power.

What is the Attitude setting?

The Attitude setting is the control setting which will change how the copter reacts to the movement you make on the RC controller, these are best left at 100% for your first flights, when you have become confident you could move these up a little higher and see if you like the “feel” of the copter. Only add 10% at a time to these figures as they will change the flight experience a lot if you go too far!

How should I mount and where should I place my A2 M & IMU on my copter?

The A2 M IMU should always be placed as close to the centre of gravity as possible, this is normally in the middle of the lower plate, and the arrow pointing to the front of the craft, however there are options to set the position of the IMU in the assist software, so you can change the position and orientation if you have to mount it in another place or orientation. The MC unit can be placed anywhere on the frame and orientation will not affect he systems operation. Please don’t use any thick foam tapes or Velcro, the M3 VHB patches which are supplied are the best way to mount the IMU.

What battery should I use with my A2 M and copter?

The DJI A2 M will support 2S to 6S batteries. The batteries used will be determined by the size of the props / motors and the weight of the craft. The batteries we use on our F450 Flame Wheels are 3S 3200 mAh Lipo, these give good 10 min’s of flight or more if you are not sport flying! The F550 Flame wheels benefit from a slightly larger battery, the 4S as they have an additional two motors and weigh a little more. On our S900 / S1000 systems use 6S batteries due to the increase in weight and longer flight times required.

What is the lowest / highest temperature I can use my A2 M in?

The A2 M can be used in the temperature range of  -5°C to +60°C, if you are going to use the A2 M below --5°C  or above the +60°C  the IMU will need to be kept warm / cool and not go beyond these figures.


What figures should I enter for the GPS / IMU in the three boxes marked X Y Z?

When you have checked your copter for the centre of gravity you will need to tell the A2 M assist software where the GPS and IMU are placed. This is very easy to do, if the C of G is below the GPS unit you will place a minus figure in the box “Z”, if the C of G is above the GPS you will enter a positive number in the box “Z”, when entering a positive number you will not need to place a “+” before it, you will only need enter a “-“ for negative numbers.
If you have mounted the GPS behind the CoG  you will need to place a minus number in the “X” box or a positive number in the “X” box if mounted in front of the A2.
The final box is the “Y”, this is the left and right mounting point of the GPS / IMU, you add a minus figure if you have mounted the GPS / IMU to the left of the C of G and a positive number if you have mounted to the right of the C of G.
All measurements are done in cm’s and are taken from the point where the C of G is, this is normally found in the centre of the lower frame plate without any additional items being added like camera mounts etc. If you add any additional parts that could / will change the C of G then you will need to reset these figures before you fly again.

If you have an unanswered questions on any systems or settings please use our contact form or call us to talk over you requirements or any setup concerns you might have with your system.