If you love the idea of building your own quadcopter, but haven’t got a clue how to start, you are definitely on the right site. We know how difficult and frustrating the research can be, so we decided to make a tutorial about building your own quadcopter using an Arduino board. We hope that you will find it useful. Here is an Arduino quadcopter in action:
Building your own quadcopter from the ground up includes plenty of hours and hard work. In the case patience isn’t your stronger side, and if you don’t posses the necessary programming skills, you can choose a quadcopter kit that is pre-built, which doesn’t actually involve serious building, and is more of an put all the parts together following the instructions, project. It is usually done in a few minutes, and you are ready to hit the skies.
But, with those quadcopters, you will miss out on the long hours and sweat invested in building, and the overwhelming feeling when you take off with your handmade quad for the first time.
Exactly the entire process of building the quad is what hobbyists love. You simply get hooked by the feeling of being involved in the entire process, from the choosing of the parts, the designing of the circuits, to the programming of your Arduino flight controller board. But, let’s start from the beginning.
How does a quadcopter fly and what it is in general?
As the name suggests, it is basically a flying vehicle with four electric motors and four propellers. When compared to other RC flying vehicles, the quad, as well as other multirotors, comes with the most stable platform, all thanks to its different design. This is why they are perfect for aerial surveillance and filming. They come in all shapes and sizes. From the small ones that can fit in the palm of your hand, to the big ones that are capable of lifting serious filming equipment and gimbals.
Contrary to the traditional helicopter, quad relies on its four rotors to generate uplifting thrust by working together. Every single rotor lifts around 1 quarter of the overall weight, which allows us to use smaller and less expensive motors. You basically control the movement of the quad by changing the amount of power each motor delivers to propellers.
They are positioned in every corner of an imaginary square. On one side, you have two motors that rotate in a clockwise direction, while the remaining two, on the opposite side, rotate counter clockwise. If this wasn’t the case, the quad would only spin around like the traditional helicopter when the tail rotor dies.
In order for the balance to be maintained, the quad relies on the data it gathers from internal sensors, and adjust the power it sends to each motor, so that the entire drone is leveled. To keep the balance all the time, the quad uses an advanced control system, which usually makes the adjustments autonomously, and this is where your Arduino board and the programming come into play.
Each quad comes capable of performing four types of movement: Altitude, Roll, Yaw, and Pitch. Each of these movements is controlled by the amount of thrust each rotor produces. This is why you need to program your Arduino controller board, so that it knows how much power to give and to which rotor to give it.
Every quadcopter comes with a microcontroller board with sensors on it, in your case the Arduino board. This board, together with the components you choose, controls the motors. It is up to you to choose how self-controlling you want your quad to be, and you can use only one or even more sensors.
Components you need for your quad
Every quad will have to include the elements listed below in order to fly:
- Frame –“backbone” of the quadcopter. The frame is what keeps all the parts of the helicopter together. It has to be sturdy, but on the other hand, it also has to be light.
- Rotors – The thrust that allows the Quadcopter to get airborne is provided by Brushless DC motors and each of them is separately controlled by a electronic speed controller or ESC.
- Arduino board
- RC Controller
The Frame of your quadcopter has to possess strength, but it also has to be flexible enough to compensate the vibrations the motors produce. It needs to have the following parts:
- Center Holding Plate – For mounting the electronics
- Arms – You need four
- Motor Brackets – You need four of them, so that you can connect the motors on each arms end.
The frame can be made of aluminium, carbon fiber or wood but the material that is mostly used for the arms is aluminium. More precisely, the square hollow rails are made of aluminium. They are relatively lightweight, rigid and cheap. But, since they are not known as great compensators for the motor vibrations like carbon fiber ones are, they can confuse the sensors.
Carbon fiber offers much better absorption of the motor vibrations, and is the most rigid one. But, it is the most expensive one. Wood boards are also better for motor vibration absorbent, but are quite fragile and can break easily in the event of a crash.
These motors are almost the same thing as traditional DC motors, but the shaft on them doesn’t come with a brush, which is there to change the direction of the power that goes through the coils. When buying these motors, you need to check their technical data.
The most important ones are the “Kv-rating“, which tells you the number of RPMs the motor is capable of generating on a certain amount of electric power. Also, you will need motors that rotate counter-wise, so that they counteract the props torque effect.
Propellers generate thrust, and each motor needs one in order for the quad to fly. Make sure that you buy the proper rotating pairs of propellers for clockwise and counter clockwise rotation. They can be bought in various pitches and diameters. You have to choose them according to the size of your frame, and once you have decided which propellers you will use, only then you can choose your motors. Propellers are standardized, and here are the most used ones for quads:
- 5 pitch, 8 diameter – Small quads
- 8 pitch, 9 diameter – Small quads
- 5 pitch, 10 diameter – Medium-sized quads
- 7 pitch, 10 diameter – Medium-sized quads
- 5 pitch, 12 diameter– Provide plenty of thrust and are great for quads that are larger
Since aerodynamics is just more than confusing and difficult to understand if you are not an Engineer in Aerodynamics, we will explain a few important terms in a few words.
First, the larger the diameter and pitch are, the more thrust will the propeller produce. It will need more power, but the quadcopter will be capable of lifting more weight. For high RPM motors, you need smaller or mid-sized propellers. For low RPM motors, you need the larger propellers so that they can keep the quad in the air at lower speed.
Second, to achieve the perfect balance between the motors and propellers, you first need to decide what you will use the quad for. For example, if you want to build a stable and powerful enough to lift a filming equipment quad, you should use a motor with less RPM’s and more torque, and longer or higher pitched propellers.
The device for controlling the speed of the motors – ESC
The device that is in charge of controlling the speed of the motors is a cheap controller board, used only for motors. It comes with an input for a battery, and has a motor output with three phases, so you will need four of them for each motor.
When buying the proper ESC, you need to pay attention is the max level of the current that comes from the source. Choose a controller with 10A or higher. Also, you need to check how programmable it is, meaning that you need to buy an ESC that will allow you to change the signal frequency range to the value you want.
The most recommendable power source for your quadcopter is the LiPo. It’s not heavy, and the current levels are ideal for what you need. NiMH is cheaper, but heavier and it is also an option.
LiPo batteries come as a single 3.7V cell, or packed together as one (up to 10 cells which provide 37V). The most popular version among the drone hobbyists is known as the 3SP1 battery, which comes with three cells and provides 11.1V.
Inertial Measurement Unit or the IMU
This unit is in charge of measuring the quad’s orientation, velocity, and the force of gravity. This allows the electronics that control the amount of power sent to motors, to adjust the motors’ speeds. The unit comes equipped with a 3-axis gyroscope, and a 3-axis accelerometer. This combination is known as the 6DOF IMU.
The gyroscope is there to read the values of angular velocity, while the accelerometer is in charge of measuring acceleration and force, meaning that it can feel the downwards gravity. Since it comes with three axis sensors, it can sense the orientation of the quad.
The flight controller
You can either choose to use a controller board that has only one purpose and that is to control a quadcopter, or you can choose an Arduino UNO. This is a general purpose microcontroller that allows you to build your own flight controller by buying the parts you want to install, and assembling the controller on your own.
If you are interested in getting started with electronics and coding, the Arduino UNO is the best possible board you can use. It is the most reliable and robust platform, and it allows you to literally play with it anyway you want. It comes with:
- 14 digital input/output pins (6 of them can be used as outputs for PWM)
- 6 analog inputs
- a 16 MHz quartz crystal
- a USB connector
- a power jack
- an ICSP header
- a reset button
You can use the USB cable to connect it to a computer, a battery, or an AC/DC adapter to power it up.
The best thing about this board is that it allows you to mess with it and not worry about destroying it. The worst thing you can do is frying the chip, which can be replaced for only a couple of dollars. You can program the “UNO” with the Arduino Software, and here are the details which will help you get started with your Arduino UNO Flight Controller.
The RC Transmitter
The most common way of programming and controlling a quadcopter is by an RC transmitter. You can usually choose between two modes, Acrobatic or Stable. For controlling the quad in Acrobatic mode, the Gyroscope is the only one who sends the values to processing. In this case, the controlling sticks are there only for controlling and setting the speed of rotation for the three axes, and if you let go of them, the values are not re-balanced automatically.
This comes in handy for those who want to perform aerial stunts, because tilting the drone a bit is possible, and after the release of the sticks, the quad keeps the position. It’s not a good mode for beginners because it is quite difficult to control your quad in this mode.
In the beginning, use the second mode because for determining the drone’s orientation, every single sensor works in this mode. The motor speeds will be controlled automatically, and the drone will be balanced on its own.
We are hoping that this article helped you and gave you a better insight to what each part of the quadcopter does. Now you should know how to select the right parts for your quadcopter. If you manage to build your own quadcopter and everything goes well, you can check out our other article about flying a Quadcopter on our site.
As a gift to you, in hoping that you will enter the world of drone hobby and stay here, here is a video that shows how to put all the parts we mentioned together and build an Arduino Quadcopter from scratch:
Feel free to leave a comment or give us some feedback on this post. Happy building!