Introduction: Build a HK X650F Quadcopter for GoPro Style Video and Photography

About: Everyone complains about the lack of money, but nobody complained about the lack of common sense ...

This is my first attempt at an instructable, so please be forgiving. Also, English is not my native language, so I will try to keep it as simple as possible. If you find some errors or incorrect information, please comment, I will try to fix it. Thank you.

Please check my second instructable on adding a retractable landing gear to my drone:

How to add retractable landing gear to a quadcopter

I have always been intrigued by flying machines, drones to be exact. I long thought about buying a Ready-to-fly (RTF) version, such as DJI Phantom or similar, but the prices for such drones are way out of reason for most east Europeans... So after longer time I decided it would be best and cheapest, if I built my own drone out of commercially available parts, then learn to fly it and set it up myself. Boy was I wrong .. :) Just kidding...

Yes it is cheaper, but it takes a long time, it is fairly complicated and it demands a lot of reading, asking, studying and countless tries to get it right. But on the other hand, it is also a lot of fun and to me, it brought dedication, concentrated effort and pure joy from creating something the way I want it to be.

The general features I wanted my drone to have were:

  • it should be a quad rotor in the X configuration
  • overall weight including battery and camera around 2.5 kg
  • flight time somewhere around 15 minutes
  • size should be within 60 x 60 x 40 cm for easy transport, ideally folding design
  • capable of automatic flight missions, so GPS was needed
  • full spectrum of wireless connectivity (radio telemetry, WiFi, Bluetooth)
  • control distance around 2 km
  • price range between 500 - 600 €

Here is a short video showing the final result, without further tuning. So this is basically what I was aiming for:

So if you are like me and are not scared of failures and sometimes disappointment, then read on, it is going to be a bumpy ride (or flight).... but the result will be rewarding. I will try to provide my own pictures, some downloaded from the net, and also insert links to important websites, where you can learn specific details about different steps. I recommend you start with this one. Next step describes the terminology, parts and tools, where I got them, at what cost and mainly why I chose the parts I used...

Step 1: Used Terms and Shortcuts

Here is the list of shortcuts and terms that you need to understand if you are an RC beginner:

  • RC - remote controlled - anything controlled remotely, wired or wireless
  • FC - flight controller - the brain of the RC vehicle, in our case a quadcopter drone
  • APM/PixHawk/PX4/CC3D/KK - different types of flight controller
  • ESC - electronic speed controller - translates commands from FC to power for the drive-train, in our case the brushless motors of the quadcopter
  • Radio/TX/Transmitter - controller used for sending commands to RC vehicle
  • RX - receiver mounted on the vehicle connected to FC and other equipment
  • PPM/PWM/S.Bus - communication protocols used between RX and FC
  • LiPo - type of battery (LithiumPolymer)
  • C rating - discharge rating of the battery
  • KV - it refers to the rpm constant of a motor - it is the number of revolutions per minute that the motor will turn when 1V (one Volt) is applied with no load attached to the motor
  • OSD - On Screen Display - overlay information from FC on to your video feed or RC transmitter
  • UBEC/SBEC - regulated power supply, integrated in ESC or standalone module for supplying regulated voltage output to your peripherals

You will often encounter these terms, in this build and also by your own RC adventure, so please take time and use google, there is a huge amount of information on the web.

Step 2: Tools and Parts

Before I get to the list of parts and tools, I need to tell you one more thing:

!!!SAFETY!!! Please be really careful, things are sharp, spinning really fast and there is electricity everywhere. Some tools get hot, so do not take this warning lightly. You will get burnt, cut or worse!!!

OK, so here is the list of tools I mainly used:

  • standard precision work screwdriver set (flat, Phillips, hexagon)
  • heat gun or soldering station, rosin core solder, solder cleaning steel wool
  • lots of electrical tape, double-sided soft tape an heat shrink tubing
  • lots of zip ties of different sizes and colors
  • Dremel tool
  • Multi-meter

Now for the parts I chose, I will give a link to a website and short comment why:

  • Frame:HobbyKing HK X650F It is a very nice, sturdy frame, in the desired size, with folding arms, integrated ESC holder, lots of mounting surfaces and free space for all needed electronics and other parts.
  • Motors:AX-2810Q-750KV Very nice brushless motor, specific for multirotor use, high power output (444 W), suitable for our size and weight. One of these babies can lift a 1.2 kg alone !!!
  • ESC:Q-Brain ESC This is a 4 in 1 integrated ESC for quadrotors, has an integrated SBEC power output, is fully programmable. Performs much better if flashed with BLheli firmware. We will get to that...
  • Flight Controller:HKPilot Mega 2.7 This is a standard Arduino based flight controller, reasonable price, all the necessary features included, lots of inputs and outputs, magnetometer, barometer, gyroscope, accelerometer, USB port, I2C port, GPS/Compass port, very god software Mission Planner.
  • GPS/Compass:Ublox Neo-M8N The top of the line GPS/Compass combo, features all of currently available positioning systems, very fast, high precision. Included is a folding mount.
  • Radio telemetry:433MHz Radio Telemetry kit complete with cables and antennas, makes it easy to connect APM to Mission planner in PC, laptop or even android tablet with OTG support.
  • WiFi module:APM WiFi module, plugs into APM telemetry port and creates a WiFi access point used to connect APM to any Wifi equipped PC, laptop or tablet/phone.
  • BT module: Generic BT module for APM
  • Transmitter/Receiver:Radiolink AT9 Very nice 9 channel TX/RX, many functions, OSD, S.bus compatible, long range, alarm, fail-safe, simply everything you need from a good transmitter.
  • Receiver OSD:Radiolink PRM-02 OSD module Plugs inline with you telemetry and relays info on speed, position, height and voltage to your transmitter screen.
  • OSD module:MinimOSD module very similar to the above, only it overlays your flight info directly on your video feed from your camera
  • Sonar module:Ultrasonic Sonar module Helps the FC to perceive the distance from ground, not only by barometer pressure changes, but with the help of ultrasonic pulses.
  • Status LED module:APM LED module gives you visual confirmation on GPS lock and Arming status.
  • Battery: Turnigy Nano-tech 5000mAh 4S battery High density battery, with high discharge rating, well balanced cells, one of the best choices in this category. But there are tons of batteries to choose from, its up to you...
  • Brushless camera gimbal:SJ2D 2-axis brushless gimbal It is cheap, it is well made, holds my SJcam 5000+ or GoPro 4 Black without problems, has integrated gimbal controller and can be easily upgraded to 3-axis.
  • LiPo alarm/Buzzer:LiPo alarm Small, lightweight LED alarm and buzzer for your battery, very loud
  • Battery balance charger:iMax B6AC Battery charger Compact, powerful charger for almost every battery you could ever use. It is microprocessor controlled, safe to use.
  • ESC programming card:Turnigy BESC card used for programming of the ESC, simple to use, works perfect.
  • Battery Power module:APM Power module supplies power to the FC and other equipment, also gives info about voltages and power consumption.
  • UBEC power source:Dual output 5V/12V UBEC module for supplying power to gimbal and other equipment
  • Propellers: 11x45 or 12x38 Gemfan propellers, it takes a lot of tuning to choose the right ones, we will get to that later
  • FC dampening:APM Damping platform simple solution to limit vibrations transferred to your flight controller
  • lots of banana connectors, XT60 connectors, servo lead cables etc.

It all cost around 600 € if you are smart, use promotions, sales, coupons etc. You can even go for second hand parts and make it even cheaper, but I decided to order only new parts, mainly from Hobbyking and high rated sellers on Aliexpress. As you can see from the parts list, this drone should theoretically be able to outperform many of commercially available drones in a much higher price range. Of course, there is the cost of the invested time to build it, tune it and learn to fly it, but it is worth to choose this path. The other advantage is repairability, highly modular structure, you can swap parts anytime you wish, upgrade, downgrade or add new parts as you like.

Step 3: Build Your Quad Frame

I have chosen this frame because it is the ideal size for my GoPro 4 Black camera, it is light and very rigid, there is almost no twist between the arms, it sits nice and level and there is enough ground clearance for a brushless gimbal between the landing gear.

It is fairly easy to build the HobbyKing X650F frame according the steps in the supplied instructions, I recommend to finish the four arms first, then the central plate where the arms are supported. I also recommend you to use a drop of screw adhesive on every screw, because the props cause a lot of vibration if not balanced well, transferred through the motors directly to the four arms and the central plate. Fixing the screws is important if you don't want you drone to disassemble mid flight....

The arms are color coded, two are black and two are yellow. I installed the yellow arms to the front of the frame, but it is up to you.

I also mounted all four motors on the corresponding motor mounts on the end of each arm. It is very simple, just use correct screws (M3x6 mm), use a drop of screw adhesive on each screw. My motors came without connectors soldered, so I also soldered 3 mm male banana plugs and used heat shrink tube to protect it from shorts. A nice video guide by Graysonhobby showing the basics of soldering can be found here. The ESC comes with presoldered 3 mm female banana plugs on the end of each motor lead.

The last pic shows the frame completely built. The first 9 pictures are not mine, I used Hobbyking website as the source, hopefully they will not sue me... :)

You do not have to install the two top central plates yet, we are going to use the space just above the arms for our ESC in the net step.

Here is a nice video of the frame assembly by Nelson Lee: HK X650F assembly

Step 4: Mount the ESC, Motor Leads and Gimbal UBEC

Next is the power system, the ESC responsible for converting commands from flight controller into power for each motor. Electronic Speed Controller in our case is a 4 in 1 QBrain 25A with integrated UBEC. I have chosen this ESC because of the integrated design. I didn't like the idea of 4 separate ESCs mounted on the arms of the quad for several reasons:

  • weight distribution, single ESC in the center of the quad is way better for flight stability
  • need for additional Power distribution board in the center of the quad
  • additional weight, more cables and connectors
  • more soldering

As you can see from the bottom view picture, between the 2 main plates that hold the arms of the quad in place is just enough room to fit the APM Power module with power cable extension, both with XT60 connectors soldered onto them. I just needed these out of the way and as close to the battery power leads as possible and this was the perfect spot. Battery will be mounted directly underneath this central plate and usually LiPo batteries tend to have short leads, so it is necessary to place the APM Power module very close. Also, this connection, the two XT60 connectors, female from battery and male from APM Power module, is the connection used for powering the quad, you will be connecting and disconnecting these connectors all the time. Be sure to zip tie the cables tightly together, so they don't get in the way of the folding arms. Those power cables have a pretty thick silicone insulation, but the arms can cut them in time when you fold the frame.

The QBrain fit perfectly on to the top central plate, just be careful not to mix up the motor leads and follow my motor numbering. In the pictures, front of the frame is on the right side (yellow arms), so:

  • motor 1 (M1) is going to the left rear arm
  • motor 2 (M2) is going to the right rear arm
  • motor 3 (M3) is going to the right front arm
  • motor 4 (M4) is going to the left front arm

As you can see from the pictures, the motor leads (the black cables) from the ESC are in four groups of three cables, they are clearly marked on the ESC enclosure. I rooted each group of motor cables through the corresponding opening in the top plate and directly through the aluminum bars to the motors. I recommend to numb the edges of the aluminum bars, those are pretty sharp and can cut through you motor leads, so use a small metal file and make them nice and smooth. It is much easier to insert the cables one by one into the bars, because the screws holding the arms in place and the motor mounts are in the way, it needs a little patience, but it can be done fairly easily. I secured the ESC in place at the exact center with double sided tape.

The QBrain is a nice ESC, flies well in factory setup, but I decided to flash it with BLHeli firmware as it is based on Silabs chips and cannot be flashed with the very popular SimonK firmware. The BLHeli firmware has lots of options to program, is much more flexible than the stock firmware and supports OneShot and Damped Light mode. This tutorial is not the place to discuss this, it is a very complicated topic, but if you are interested in flashing the BLHeli firmware to your QBrain ESC, here are the links to more information:

Yo will need some additional hardware for this step, programming board (I used Arduino Nano), some servo cables and a current limiter. You can use a programmable power supply and limit it to 500mA or build a simple current limiter as I did. Here is a nice video by Jason Hitesman on how to build your own current limiter.

I also installed the UBEC module supplying 12v to the camera gimbal on the right side next to the ESC. It is a nice little dual port module, it can supply 12v and 5v at the same time. It also has an external On/Off switch on a short cable that can be placed in some place easily accessible. Power input of the UBEC is connected directly to the power leads of the battery (power cable extension) and the 12v output is connected directly to power input of our brushless gimbal controller. Cables are zip tied and hidden between the two central plates under the UBEC as in the last picture.

Step 5: Mounting TX Reciever, GPS, Telemetry, OSD, WIFI and BT Modules, Sonar and Status LED

The ideal place for the sonar, is on the bottom central plate, facing down on the right side of the quad. I secured it in place with double sided tape and zip tie. it should be level with ground and have unobstructed "view" of the ground, so no landing gear or gimbal should be in the way. It works simply by bouncing short beeps again the ground and measuring the echo response. It works between 0.10 m and 5 m very well, makes the low flight very stable and helps the quad to maintain the same altitude in hover mode. Above 5 meter it is overridden by the APM built in barometric pressure sensor. It is powered from the APM, so just guide the 3 line cable up through the central plates, we will connect it later to the APM.

I found out, that the best place to install the Status LED module is on one of the rear arms, on the inside. So when you launch the drone and it is facing away from you, you can clearly see the LEDs. There are 2 LEDs on the module, the red one tells you the Arm/Disarm status and the blue one the GPS lock. You can read more about each of the statuses displayed on the ArduCopter website.

Now, the so called "communication platform" is the first level above the central plate (in between is the ESC and UBEC). This is the obvious location to install all the optional modules, it has plenty of space, lots of cut outs and openings for cables and is shielded from the electromagnetic interference of the ESC by the carbon plate and the cooler/shield on top of the ESC itself. It doesn't really matter how exactly you position the individual modules, just keep in mind that the antennas should not be next to each other and that the supplied cables need to reach the top platform, where the flight controller will be installed. As you can seen from the two last pictures, I installed the R9D TX/RX receiver in the front part (double sided tape), where the GPS stand is installed, because it is the biggest module and needs to be accessible from its top side (OSD telemetry port), next I installed the GPS folding stand which is secured in place by a single screw from the bottom and rotated so it folds to the front of the quad.

In the last pic you can see from left to right:

  • MinimOSD module
  • BlueTooth module
  • WiFi module
  • 433 MHz 3DR radio telemetry
  • and hidden in the middle is the Radiolink PRM-02 OSD module connected to the R9D receiver telemetry port

Note that you cannot use all connection possibilities at the same time. The APM is able to communicate only with one module at a time, because it only has one Telemetry port. You can use a Y-cable to connect an OSD module inline with a communication module, but that is it. If you would want to use more telemetry communication modules, you would have to switch to a more complex flight controller as Pixhawk which support more I/O telemetry ports simultaneously. In my configuration, I use the WiFi module and the Radiolink PRM-02 OSD module connected with a Y-cable splitter. I use the WiFi to connect to my Android tablet using Tower Software and the PRM-02 transfers information about important system status to my Radiolink AT9 Transmitter. Every module is held in place by double sided tape and/or zip ties. More on installing and setting up a telemetry connection can you find here.

If possible, tidy up the cables so they don mix up and interfere with each other, if you are handy with crimping tools and have some spare connectors, make the cables shorter and save space and weight. I just tied it together and to the carbon plate. You don't want the cables to move in flight, it could lead to disconnecting of a connector or tangling into the propellers and crashing your quad....

One more warning... be very careful with those cables, those are very thin and fragile, tend to break easily, so take a time and make it right. I myself have damaged some and had to make new ones from spare connectors and cables.

Step 6: Mounting the APM Flight Controller

OK, so now it is time to install the top most level of the frame, where the flight controller will be.It is as simple as screwing on the last three remaining pillars, with a drop of screw glue. Now comes the anti-vibration/damping platform, secured in place with double sided tape. It eliminates the vibrations of the motors and propellers so it doesn't influence the flight controller. Make it nice and center. You do want the flight controller to sit at the absolute center of the drone, it is good for flight stability, because of the internal accelerometers and gyroscopes in the flight controller. You can see clearly from he pictures how I installed the APM on top of the damping platform. Do not worry about the orientation of the APM yet, you can see I installed it 90 degrees to the left against the front of the frame, where the GPS stand is. You can set the real orientation later in Mission Planner. Secure the APM in place with tape and again, try to center it. More information on this topic is here.

Now all the cables. Yo need to guide each cable from the bottom levels to the top platform, through the openings in the top platform and into corresponding port on the APM. First of all, install the GPS module on the stand. I used tape, just make sure, that the arrow on the GPS module is pointing forward, it is the compass orientation, and it is necessary for the flight controller to be able to determine correct heading and orientation. There are 2 connectors coming from the GPS module, one is a 4 pin I2C for the compass and the other is a 5 pin GPS that goes into the top GPS port on the APM. In my case, the GPS module was equipped with a 6 pin connector for PixHawk controller, I had to swap it for a 5 pin connector. Use a zip tie to secure the cable to the stand. If the cable is too short, you will have to cut a piece of the GPS stand with a Dremel tool, so it wont pull on the APM when folded down. You can read more about this topic here.

Next step is connecting the ESC control leads and TX/RX receiver to the APM. The ESC has four cables for communicating with the flight controller. One of those is a UBEC cable with three leads (Black/Red/White), other three are single leads (Red/Brown/Orange). You need to plug these into the APM output ports, as in my pictures, if you connected the motor leads exactly as described in the ESC installation step. Be sure to follow the colors and ports, it is very important:

  • Output 1 - Black/Red/White cable
  • Output 2 - Red cable
  • Output 3 - Brown cable
  • Output 4 - Orange cable

Watch the polarity of the first cable, bottom pin is always Ground (black) central pin is Power (red) and the top pin is Signal (white). Mind that I have the side-pin version of APM, there is also a top pin version, where the outside pin is Ground (black), the central pin is Power (Red) and the inside pin is Signal (white). Do not mix this, or you will damage your APM or ESC!!! The other 3 cables have just a single lead and these always go into the top pin (Signal).

Now the receiver. In this build I use the Futaba S.Bus communication protocol between Receiver and APM, I wont go into details, just follow my lead, you can find a lot of info about it on the web if you wish. We need just a single 3 pin servo cable and a common jumper used in PC. Put one end of the servo cable into the S.Bus port of the receiver and the other end into the Input port 1 (channel 1) on the APM. Watch the polarity, servo cables are usually color coded, so use white lead as Signal (top pin on the APM). You can see it on the Picture No.8. Next insert the common PC jumper into top pins of channel 2 and 3, basically you should short the Signal pins(top) of second and third channel on the Input side of the APM. This tells the APM to switch the protocol to S.Bus, where all channels are transferred through single line. Less cables, less weight, more space and less errors. Insert the 4 pin cable from the Radiolink PRM-02 OSD into the top port of the receiver and you are set. More information on connecting a receiver to the APM is here.

Next guide the power supply cable from the APM Power module up to the APM and connect it to the APM power port, next of the I2C port on the Output side of APM. It is the only 6 pin connector, you cant go wrong. This cable supplies regulated power to the flight controller and also information about power levels, voltages, currents that you can view in Mission planner on onscreen in Tower or through OSD in your video feed. Instructions on setup can be found here.

Connect the sonar cable to the A0 port on the APM, it should be marked, it is the first pin row next to the Telemetry port on the APM, again, check polarity, Black (Ground) is on the outside, Red (Power) is in the middle and Signal is on the inside. You need to setup Sonar in Mission Planner, here are the steps.

Now for the LED/buzzer module, I secured it on the inside of one of the rear arms, an led the cable through the plates to the APM, the are 2 connectors, connect those as per instructions in the pictures or on the Arducopter website. Buzzer

This is it, nearly all your components are installed, we just add the brushless camera gimbal and after you go through some basic setup steps in Mission Planner, you are ready to go, or fly to be more exact :)

Step 7: Install Your Brushless Camera Gimbal and Battery

It is very easy to install the gimbal, it comes fully built, you just snap on the hooks on to the two 10mm carbon tubes on the underside of your frame, connect one cable to your 12V UBEC output, and one cable to the A11 port on the APM for Pitch control. You need to configure the gimbal in Mission Planner, the instructions are here. I recommend assigning a free channel on your transmitter to a turning knob, for easy pitch control. APM does not provide any stabilization for the gimbal, it is all in the hands of the gimbal controller and its gyros and accelerometers. And I can say it does a pretty good job, the video is butter smooth. APM can however change the pitch of the gimbal when in Auto mode and you have setup a Point of Interest as one of the steps of automatic mission. It will keep the camera pointed at this spot at all times, even rotate the drone so it always points its nose to the target. Very nice feature.

I recommend pushing the gimbal forward on the carbon tubes, so as to get the propellers and landing gear out of Field of View of your camera, it disturbs the image a lot.

Now secure your battery in place on the battery holder with a Velcro strip or a dedicated battery strap. The battery is very heavy, it is in fact heavier than your frame, so it will shift the center of gravity of the entire drone a lot when moving. It is not good, so try to keep it in one place, all the time. You can try to balance you entire drone on one center spot from the underside and move the gimbal and battery front and back until it is nicely balanced. You don't want your first takeoff to be a flip, because of a heavy rear end :)

Step 8: Binding the Receiver, Calibrating Throttle and Setting Motor Spin Direction

Our Radiolink transmitter/receiver combo has a nice auto binding feature. It is described in the manual but I will tell you how to do this. You just need to do this once. Install batteries in the transmitter, plug in your LiPo battery, that should power on your receiver as well as the rest of the drone. Ignore the rest, just focus on the receiver. Place the transmitter and receiver within 1 meter from each other. Turn on the transmitter. There is a small button (ID Set) on the side of the receiver, you need to press it for one second and the LED indicator will start flashing. It will automatically find the nearest transmitter and bind to it. It will light solid red and the transmitter will show you the signal strength on its display.

Now we need to switch it into S.Bus mode. Short press the ID Set button 2 times within 1 second and the signal should change from normal PWM to S.Bus mode. The color of the LED should change to a solid Blue/Purple.

Now we need to do ESC throttle calibration. It is important, because it tells the ESC what are the maximum and minimum values of throttle from the flight controller.

  1. Turn on your transmitter and put the throttle stick at maximum
  2. With the transmitter throttle stick still high, disconnect and reconnect the battery
  3. The autopilot is now in ESC calibration mode. (On an APM you may notice the red and blue LEDs blinking alternatively on and off like a police car)
  4. Wait for your ESC to emit the musical tone, the regular number of beeps indicating your battery’s cell count (i.e. 3 for 3S, 4 for 4S) and then an additional two beeps to indicate that the maximum throttle has been captured
  5. Pull the transmitter’s throttle stick down to its minimum position
  6. The ESC should then emit a long tone indicating that the minimum throttle has been captured and the calibration is complete
  7. If the long tone indicating successful calibration was heard, the ESCs are “live” now and if you raise the throttle a bit they should spin. Test that the motors spin by raising the throttle a bit and then lowering it again
  8. Set the throttle to minimum and disconnect the battery to exit ESC-calibration mode

Your ESC is now calibrated. More info is here.

Now we need to check the spin direction of each motor. In a quadcopter diagonally opposing motors spin in the same direction. Either clockwise (CW) or counter-clockwise (CCW). We are using so called Quad-X configuration. As you can see in the picture, we need to make the motors spin in the required direction. It is as simple as swapping two out of three motor leads. Remove the propellers if you have them on, you could get seriously hurt with props on. Power up you drone by connecting the battery, arm the drone by holding throttle down and right for 3 seconds, then slowly raise the throttle just until the motors start to spin. If some of the motors pins in wrong direction, just power of your drone by disconnecting the battery and swap two motor power leads. this will in fact change the rotation direction of the motor. After you have done this, try spinning the motors again and make sure, they are all spinning in the right direction. You are done now. You can read all about this in this article. There is also the description of propellers, it is very important that you don't mix up your props. There are two types, pushers and pullers. Otherwise your quad will flip instantly on takeoff. You don't want that !!! It is always good if your propellers are well balanced before attempting first flight, it helps to make the drone more responsive, stable and eliminates unwanted vibrations that could ruin your video. Here is my short video clip showing how a good balanced propeller should behave on on a cheap maglev balancer:

Step 9: Loading Firmware and Connecting to Mission Planner

First of all, you need to install Mission Planner software on you ground station computer. I found out that for me it is best to use my laptop, I can take it into field with me and change advanced parameters on the spot. Download the Mission Planner from here. Install it and follow instructions on this page to load a new firmware to your APM. You see, the APM comes without any firmware preloaded, so you need to do this step first. Be sure to choose the Mission Planner’s Initial Setup | Install Firmware screen and click on the APM:Copter Quad. This will install the correct firmware for APM flight controller.

Then you can try to connect your APM to Mission planner. The instructions are here.

Remember ONE very important thing! Never connect your APM to your ground station PC over USB with your drone battery plugged in. It could lead to a dead flight controller. Before connecting your APM to your PC over USB, always unplug your battery. This does not apply if you connect over Bluetooth or WiFi or Radio Telemetry, it is just a power problem with USB and the built in power regulator.

Step 10: Calibrating Your Quadcopter in Mission Planner

Ensure that your drone is powered, props are removed and your radio transmitter is On and bound to your receiver. Always disconnect your battery if you are connecting to your APM over USB !

First step is choosing the right frame type:

When connected to MP, choose Initial Setup screen, select Mandatory Hardware / Frame Type. Select the frame for your copter. Our configuration is X, so choose this option.

Second step is Compass calibration:

  1. Under Initial Setup / Mandatory Hardware select Compass.
  2. Select the correct orientation for our setup (ROTATION_ROLL_180). Ensure the Enable compasses and Obtain declination check boxes are checked
  3. Select APM with External Compass.These options will automatically enter the correct orientation for the board. Ensure that you have mounted the GPS with Compass with the arrow facing toward the front of the vehicle.
  4. Click on Live Calibration.
  5. A window should pop-up informing you that you have 60 seconds in which to rotate the APM around all axis. Press OK, countdown window should appear to show that the Mission Planner is collecting compass data. During these next 60 seconds you should hold the drone in the air and rotate it slowly so that each side (front, back, left, right, top and bottom) points down towards the earth for a few seconds in turn.
  6. Upon completion, another window will pop up showing you the new offsets that it calculated.

A nice video on Live compass calibration by Randy Mackay can help you with this.

Next step is Radio Control calibration. This basically tells the APM, how big is the travel of each radio stick/switch/knob. It measures the lowest and highest values of your radio transmitter. What you need to do is very simple:

  1. Open Mission Planner’s Initial Setup / Mandatory Hardware / Radio Calibration screen. If your RC receiver (Rx) and transmitter (Tx) are bound, you should see the green bars move when you move the transmitter sticks.
  2. Click on the green Calibrate Radio button in the lower right of the window.Mission Planner will display a prompt to check radio control equipment is on, battery is not connected, and propellers are not attached. Select OK.

  3. Move the control sticks and toggle switches on your transmitter to their limits of travel and observe the results on the radio calibration bars. Red lines will appear across the calibration bars to indicate maximum and minimum values. You should also calibrate the channel you have selected for controlling vehicle mode, and any other channels you have connected to the autopilot.

  4. Select Click when Done when all required channels are set at the minimum and maximum positions.Mission Planner will show a summary of the calibration data. Normal values are around 1100 for minimums and 1900 for maximums.

Last thing we will calibrate is the built in accelerometer:

  1. Under Initial Setup / Mandatory Hardware, select Accel Calibration from the left-side menu.
  2. Click Calibrate Accel to start the calibration.Mission Planner will prompt you to place the vehicle each calibration position. Press any key to indicate that the autopilot is in position and then proceed to the next orientation. The calibration positions are: level, on right side, left side, nose down, nose up and on its back.
  3. Proceed through the required positions.
  4. When you’ve completed the calibration process, Mission Planner will display “Calibration Successful!”.

The steps are described in more detail here. Nice video by Randy Mackay shows the same steps.

Congratulations, your flight controller is now calibrated and we can proceed to the next setup step.

Step 11: Configuring Flight Modes and Transmitter Setup

The Arducopter code supports a lot of different flight mode, some manual, some automatic, some with GPS assistance. Remember, if you want to use GPS assisted modes, you have to wait until your GPS module acquires 3D position lock, signaled by the blue LED on the APM and your LED module going solid blue. Do not try to fly in GPS dependent modes if you do not have a GPS lock, the craft will behave erratically or wont fly at all. These modes are very important for you to study, learn and understand. You can learn all about flight modes no the Arducopter website. I usually use 6 flight modes, that I configured on my Radiolink AT9 transmitter with the help of combination of 2 switches, one 3-position switch and one 2-position switch. I will here in short describe my preferred flight modes and how I set those up:

  • Stabilize - it is the most common mode for drone fliers, it is a fully manual mode, the flight controller keeps the drone level, but you have full control of throttle, rotation and front-back-left-right movement. This is also the most challenging mode to fly as a rookie, but gives you the most control over your craft.
  • Position Hold (P.Hold) - this is a GPS assisted flight mode, you have full control of throttle and direction, but the drone maintains a constant location, heading, and altitude. It is generally popular because the pilot stick inputs directly control the vehicle’s lean angle providing a more “natural” feel.
  • Return to Launch (RTL) - also GPS assisted, when RTL mode is selected, the copter will return to the home location. The copter will first rise to RTL_ALT before returning home or maintain the current altitude if the current altitude is higher than RTL_ALT. The default value for RTL_ALT is 15m. Very helpful when ending a flying session, it helps to bring your drone home fast and to the point where it was firs armed. The drone
  • Hover (AltHold) - with altitude hold mode, the throttle is automatically controlled to maintain the current altitude. Roll, Pitch and yaw operate the same as in Stabilize mode meaning that the pilot directly controls the roll and pitch lean angles and the heading.
  • Auto - in Auto mode the drone will follow a pre-programmed mission script stored in the autopilot which is made up of navigation commands (i.e. waypoints) and “do” commands (i.e. commands that do not affect the location of the copter including triggering a camera shutter).
  • Land - very simple, if you activate this mode, the flight controller will try to bring the drone straight down and land on its current position if you have a GPS lock.

So these are my preferred flight modes, you can choose any mode you want, but if you want to setup the same as I have, just connect to Mission Planner, on the Config/Tuning page select Flight Modes and setup individual modes according the first picture. Now you need to setup your Radiolink transmitters switches. To help you, I have taken a picture of every relevant screen on my transmitter, so just read the manual and change your values according to the values in my pictures. The most important is the last picture, showing the mixing of two switches SwC and SwD in the Attitude screen. Those are on the top right corner of your transmitter marked with letters C and D. Just follow my lead and you should be OK.

One important thing is, at least on my unit, the throttle channel was reversed from the start, so it was on full throttle with the stick down and on no throttle with the stick in top position. If this is your case also, you will need to go to the Reverse screen, and change the 3:THRO value to REV. Now it should be correct.

Step 12: OK, You Are Ready to Fly :)

Do not rush to fly the minute you finished your drone ! If you are a complete rookie, first of all, calm yourself. If you are like me, you will be shaking, the hair on your neck will stand straight and knees will weaken.

Here is a nice video on learning drone flying by, the whole website is worth checking out, some nice tips on first time flying. I suggest you stop now, and watch the videos and read all the information.

Check everything, every cable, every connector, tighten your propellers again. Take time. Grab your camera and take some pictures... It is possible this is the last time you see your quad in all its glory, clean, unbroken, working :)

Wait for a nice day with no wind and no low sun (it may blind you). Find a place with lots of free space, no trees, power lines or other obstacles. Under no circumstances try to fly this beast indoors. You will break it or hurt someone. Set the drone on a nice and level surface / ground, clear of high grass facing away from you. Just stand behind its back. Check everything again. Really. You will thank me if you find a loose connector.

Connect the battery and wait for a GPS lock. Walk a few steps back, so if something goes wrong, you are away from propellers reach. Arm your copter by holding the throttle stick down and right for 3 second. The drone will long beep and the status LED will turn solid red.

Say your prayers, steady your hands and move your throttle slowly up...

Good luck and happy flying :)

Here is a video of my maiden flight:

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