This guide shows how to build and set-up a quadcopter with the MultiWii v2.5 board.
It's not mandatory to use the same models and brands as ours, you can search for different options, but
There are plenty a lot of boards you can use to control your UAV, in our case we are using the CRIUS MultiWii v2.5, that features an ATMEL Mega 328P microcontroller, and in-built accelerometer, gyroscope, barometer and magnetometer. The board name comes from the MultiWii open source software project, aimed to the control of RC controlled multi rotor flying platforms. Here you can find more information about the project, and download the codes and software that we will use in the board configuration. For this step we'll need the MultiWii codes and GUI (that can be found here). We're using the 2.4 version, that is the last available at this time. To edit and flash the software to our board we will use the Arduino Software. Under the "MultiWii 2.4\Multiwii" folder, that were downloaded before, you'll find the MultiWii.ino file, use it to open the code files on the arduino software. Open the codes on the arduino software and look for the config.h tab, there will be the configurable parameters of the software that will be uploaded to the board. In this file we'll just worry with the first section of the configurable parameters. To select an option you just have to uncomment its line. These are the options that we might have to change:
For all the other options we'll keep the default values, but you can change them according to your needs. Now you can go into the Tools menu, on the arduino software, to select a compatible board and processor. For our MultiWii we are using the "Arduino Pro or Pro Mini" with the "ATmega328 (5V, 16MHz)". To connect the MultiWii to the computer we'll use the FTDI Tool, look at the BLK and GRN indications on both boards to connect it right, as in the image. Once you've done that use the "Verify" button to compile the sketch, and if everything is ok, use the upload button to upload it to the board. Once we've uploaded the software to the board, we are able to use the MultiWiiConf GUI, downloaded with the codes. Under the MultiWiiConf folder find your OS folder, and run the MultiWiiConf ("MultiWi 2.4\MultiWiiConf\YourOS\MultiWiiConf").
Now you must calibrate some of the board's sensors.
You can start by attaching the motors and the ESCs to the frame, as shown in the image. The next thing we'll connect is the receiver to the board. Take a look at the pins indicated with blue lines: It shows where to connect each channel of the receiver. In our case, these are the receiver channels functions:
So you can connect each pin to its corresponding channel. In our receiver the second and third lines of pins are used for the energy supply, the second line is common 5V, connect it to de "+" pin on the board, and the third line is the common ground, corresponding to the "-" pin on the MultiWii. The ESCs are the next thing we'll connect to the board. How we'll do it will depend on the multirotor type. The following image show how to connect each ESC according to the type. We are using the quad X configuration for our multirotor, so we just have to look at the configuration type image to see which ESC we must connect to each pin. For an example, if the motor is marked with 10 in the image, connect the corresponding ESC cable to the D10 pins on the MultiWii. Pay attention to the wires order in the pins, in our ESCs the black wires are the ground, the red ones are the Vcc, and the whites are for the square wave.
There we see the motors 11 and 3, respectively, note that the black and yellow connections are reversed from one to another. The connection of the motor 10 must be equal to the 11, while the connections of the 3 are equal to the 9, this for a quad X.
The image shows how the ESCs are connected to the battery. Our frame works as the power distribution board, we just have to solder the ESCs power wires and the battery connector wires to the corresponding spots on the board. Connections on the board:
A, B and C corresponds to the ESCs connectors, and Y, R and B represents respectively the yellow, red and black wires of each motor.
If you try to do that and it works, your remote controller is probably ready to go, that was not the case with our Turnigy TGY 9X. These are the steps to get the TGY 9X to work:
The STICK SET in MODE2 corresponds to that: Now the remote controller must be able to turn the board on. If you have a different remote controller you might have to search for different orientations, but the numbers should be the same for our MultiWii.
The MultiWii offers you different flight modes, depending on which sensors it's using, and your needs while controlling your multirotor. The following table shows which mode makes use of each sensor ( x = required hardware, o = recommended hardware):
The PID tuning is made through the MultiWiiConf GUI, and it is the fine adjust of your UAV. It'll depend on the quadrotor behavior when it's taking off, landing and the attitude when flying. Here you'll find more information about what is the PID, how it works, how its coefficients values will affect the attitude of your VTOL and how can you tune it.
To change a value click and hold it, then slide the pointer to the right or left, to respectively increase or decrease the value. The above instructions tells the basics of how to set-up a multirotor using a MultiWii flight control board. Despite that we're using quadcopters in X configuration, the steps can be easily adapted to other build types. There are plenty a lot of material on the internet about this subject, and in the end of this page you'll find a lot of links leading to where the information here comes from. The finished quadcopter: The battery plugged, and the board armed: MultiWii 2.4.zip - MultiWii v2.4 files. Taken from the MultiWii open source project page Quadcopter beginner guide - A good read for beginners MultiWii - MultiWii open source project page MultiWii wiki - MultiWii project Wiki Flight modes - More information about each flight mode and its sensors PID Tuning - Information about how a PID works, and how its coefficient values will affect the attitude of the multirotor Youtube playlist with tutorials and tips - This link leads to a youtube playlist that contains a guide to set-up a MultiWii multirotor and a lot of information and tips related to the subject Arduino software - Link to the Arduino software, that we use to edit the MultiWii codes and send the software to the board Tutorial for the MultiWiiConf GUI - More detailed information about the MultiWiiConf GUI and its usage |