I have always want to play drones, and I have rented a big found for flying. Fortunately, TELLO has been found recently, I have bought an addiction. By the way, the integrated barcode scan function is tried. Now there are many warehousing management to use drones to scan the code inventory.

Python 3 Control TELLO UAV

DJI's official GitHub warehouse has already put sample codedji-sdk/Tello-Python. However, this code can only support Python 2.7, and it is also no longer maintenance. To run this code on Python 3, you need to make some modifications.

First get the source code:

git clone https://github.com/dji-sdk/Tello-Python.git

Open the project in VSCode, replace the following sections through the global search:

# 2.7
import Tkinter
# 3.7
import tkinter
 
# 2.7
print ""
# 3.7
print()
 
# 2.7
packet_data = ""
# 3.7
packet_data = bytes()

In addition, the H264 decoding library needs to be recompiled into the version of Python 3. My environment is Windows, first download compilationvcpkg:

git clone https://github.com/microsoft/vcpkg
cd vcpkg
bootstrap-vcpkg.bat

Then install vcpkgffmpeg：

vcpkg.exe install ffmpeg:x64-windows

Next, compile the Python module of the H264 decoder:

git clone https://github.com/DaWelter/h264decoder.git
cd h264decoder
python setup.py build_ext --cmake-args="-DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]/scripts/buildsystems/vcpkg.cmake"

You can now run TELLO sample code using Python 3:

python3 main.py

Integrated Python barcode identification SDK

Barcode recognition will occupy the CPU. If you run in the python thread, because Python's GIL will cause video stream carton. Use the DynamSoft Python barcode to identify SDK to avoid this. Since the supplied video stream decoding interface is running on the C / C ++ thread:

• start_video_mode()
• append_video_frame()
• stop_video_mode()

Install Python Barcode SDK:

pip install dbr

intello.pyCreated in the fileBarcodeReaderObject:

from dbr import *
self.reader = BarcodeReader()
self.reader.init_license('LICENSE-KEY') # Get license: https://www.dynamsoft.com/customer/license/triallicense

Set parameters and callback functions:

parameters = self.reader.init_frame_decoding_parameters()
self.frameWidth = 640 # max: 960
self.frameHeight = 480 # max: 720
self.results = None
parameters.image_pixel_format = EnumImagePixelFormat.IPF_RGB_888
parameters.max_queue_length = 2
parameters.max_result_queue_length = 2
parameters.width = self.frameWidth
parameters.height = self.frameHeight
parameters.stride = self.frameWidth * 3
parameters.auto_filter = 1
self.reader.start_video_mode(parameters, self.on_barcode_result)

Tello's camera is known to be 720p. I am ready to narrow the resulting image to 640x480.

Save the result in the callback function for UI draw:

def on_barcode_result(self, data):
    self.results = data

Find a video stream receiver function_receive_video_thread(). Reduce the frames and put them in the decoding queue:

for frame in self._h264_decode(packet_data):
    self.frame = cv2.resize(frame, (self.frameWidth, self.frameHeight))
 
    try:
        ret = self.reader.append_video_frame(self.frame)
    except:
        pass

Finally, in the destructorstop_video_mode()：

def __del__(self):
    self.reader.stop_video_mode()

test

I did test in the office. From the display effect, it is not very ideal. In an environment in which the light is poor, the image is not focus:

In addition, there will be problems with hovering. The TELLO drone hovered in the office drift.

Source

https://github.com/yushulx/tello-drone