#the4thLichuangcompetition#Bluetooth version of small four-axis drone-Zhixuan No.1

Note: * is required.

[Please fill in during the registration stage↓] * Brief introduction to the work: Secondary development based on open source small four-axis UAV data on the Internet. The main goal is to omit the remote control board and integrate the NRF2401 communication of the four-axis UAV board. Omit it and switch to Bluetooth 2.0 communication, which connects directly to the mobile phone to achieve short-distance communication and remote control of the drone via the mobile phone APP, thereby reducing the production cost and technical difficulty of personal DIY small four-axis drones.

[Please fill in during the competition stage↓]   1. Details of the work; 1. Picture display of the work: Screenshot of the front of the PCB                  Screenshot of the back of the PCB                  3D proofing 8520 coreless cup motor bracket footing (to prevent the motor from being fixed crookedly and the installation height is different)              2. The function of the work Description: The Bluetooth version of the small four-axis drone uses the BT2.0 module to communicate with a mobile phone or PC. The operation and parameter settings of the drone have been implemented using Bluetooth serial communication. In this way, it is an independent aircraft. You can connect and control it with your mobile phone.   2. Describe the challenges faced by the work and the problems it solves; There is a lot of open source information on small four-axis on the Internet, from PCB to flight control source code, which can be found everywhere. It is really difficult for a flight control novice like me to have never worked on a four-axis For aircraft, if you don’t even know what the flight control algorithm is and just build a drone, you can only “move bricks”, and you can only move bricks with the lowest technical threshold. Therefore, I collected a lot of flight control information from the Internet and looked at many implementation plans, and finally chose the "DST open source small four-axis" to test the waters. There are three reasons. First, its main control chip is STM32F103C8T6, a very popular microcontroller that I am very familiar with. Second, its cost is low, and I can make it cheaper to DIY by omitting the remote control board. One set is enough for less than 100 yuan. Third, after seeing its PCB structure, I had a new idea. I wanted to add an electromagnet to it to carry small objects, so that small valuable objects such as medicine spoons and game coins can be picked up and put down in flight. , that would be more entertaining. Challenges faced: The first time I came into contact with a drone, I first had to make it fly. I think this was my biggest threshold. Problems solved: The remote control board is omitted, and the mobile phone APP controls the flight of the aircraft through Bluetooth, thereby reducing the production cost of a DIY small quadcopter by half. The entire system saves the remote control part, simplifies the software program, and reduces the technical difficulty. The installation structure solves the problem of inconsistent inclination and height of the coreless motor and PCB installation.

* 3. Describe the key points involved in the hardware and software parts of the work; The hardware circuit board is modified from the flight board of the "DST open source small four-axis drone", the unused parts are deleted, and an electromagnet is added. The control interface is as shown below. I only use one circuit here, because using mobile phone Bluetooth communication, the original remote control board is no longer needed, saving half the money and debugging time. For specific changes, you can see the original PCB file I uploaded later, or the project I shared on Lichuang EDA https://lceda.cn/editor#id=|60b4edc5c19b4cffbb72b4bfa24b3eeb  . The software engineering directory is as shown below: the framework of the program has not been changed, the relevant drivers and functions of SPI communication have been deleted, and the serial port is used to realize data communication. It can communicate directly with the computer or mobile phone through Bluetooth, and the communication has also been changed according to the anonymous host computer. command, you can directly use the anonymous host computer to view the operating parameters and calibration sensors of the Bluetooth version of the small four-axis UAV. The communication instructions for controlling the drone through the APP have also been added, allowing the drone to be flown directly using a mobile phone.

* 4. List of materials for the work; Accessories: Motor fixed support (3D printed part), 4 forward and reverse coreless cup 8520 motors and slurries (two forward and two reverse), one BT2.0 Bluetooth module, slurry protective cover (required) equipment, safety first), 3.7V 350mAh lithium battery, rubber band (for fixing the battery). BOM list of PCB: | 2.2NF (222) ±10%16V X5R | | 22PF (220) ±5%50V C0G | | 100NF (104) ±10%16V X7R | | Green light | | 1UH ±10% | | AO3400A N-channel X0YV1T SOT-23 | | 10KΩ (1002) ±1% | | 22KΩ (2202) ±1% | | 470Ω (4700) ±1% | | 0Ω (0R0 ) ±1% | | STM32F103C8T6 | | MPU-6050 | |

* 5. Upload pictures of the work; (the PCB must have the contest logo on it and take a photo and upload it, if not, it will be deemed as giving up the competition) 1. 3D printed motor footings

2. Proofing PCB

3. Assembled small four-axis UAV 4. PID debugging of small four-axis UAV 5. Calibration of MPU6050 sensor. I always say that the sensor of my aircraft is not calibrated properly, so I will enlarge the trick and float it in the basin to calibrate it. You can always keep it level.

* 6. Demonstrate your work and record it as a video for upload; (The video content must include: introduction of the work; function demonstration; performance test; close-up shot of the competition logo on the PCB. Failure to do so will be deemed as giving up the competition) Bluetooth small four-axis drone 1 Zhixuan No.1 PID calibration https://v.youku.com/v_show/id_XNDM2Nzk3MjIyMA==.html?spm=a2h3j.8428770.3416059.1 Bluetooth small four-axis drone 2 Zhixuan No.1 flight video https://v .youku.com/v_show/id_XNDM2Nzk3MjI0MA==.html?spm=a2h3j.8428770.3416059.1 Bluetooth small four-axis drone 3 Zhixuan No. 1 flight video https://v.youku.com/v_show/id_XNDM2Nzk3MjI1Ng==. html?spm=a2h3j.8428770.3416059.1 Bluetooth small four-copter drone 4 Zhixuan No. 1 outdoor flight video https://v.youku.com/v_show/id_XNDM3MDI3MTYyNA==.html?spm=a2h3j.8428770.3416059.1

7. Open source documents. The project information comes from the Internet and all secondary development materials are also open source. Secondary development materials are for study and research only and may not be used for commercial purposes without my permission.