AirPost_Station — the smart landing pad (IoT)

This repository is a landing station in the AirPost drone-delivery system: the physical helipad a drone takes off from and lands on, made "smart" by a Raspberry Pi and a handful of sensors.

What it is, in plain terms

A station is a small always-on IoT device sitting under a helipad with an AprilTag marker. Its job is to make the pad known, safe, and landable at any time:

• Knows where it is — a GPS module reports the pad's exact coordinates, so the backend can route drones to it (no hardcoded map).
• Knows its condition — temperature, humidity and a light sensor report the pad's environment.
• Stays landable at night — when the light sensor reads "dark", the station turns on a pad LED (lamp) so the drone's downward camera can still see the AprilTag and precision-land. This is the station's key trick: vision landing needs light, so the pad provides its own.
• Checks clearance — a Pi camera can verify the landing space is clear.

Where it sits in AirPost

AirPost_Station (Raspberry Pi)
  ├─ GPS, temp, humidity, light  ──MQTT──► Sink ──► Kafka ──► backend (map + dashboards)
  └─ light sensor "dark?" ──► turn ON pad LED ──► drone camera can read the AprilTag at night

The station continuously publishes its sensors over MQTT; the Sink forwards them to Kafka, and the backend stores/charts them and shows the station on the live map. The night-lamp rule is driven by the light reading (locally and/or via the backend's logic engine).

In the simulation, station_iot.py plays this exact role: each station self-registers with the backend and streams GPS/temp/humidity/ light, raising a virtual pad lamp in the dark — so the simulated world behaves like these real boards.

The rest of this README is the hardware list and the Raspberry-Pi bring-up (wiring and installing the GPS, camera, DHT11, light sensor, LED, and the MQTT client).

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Companion Computer

• Raspberry Pi

Sensors

• USB-Port-GPS Module SKU:EZ-0048

  

  To specify station coordination through gps.

  Wiki

  Product Link

• Raspberry Pi Camera Module V2

  

  To measure cleaerence of landing space

  Product Link

• DHT11 Temperature, Humid Sensor

  

  To measure status of landing space.

  Product Link

• Light Sensor

  

  To measure light value of landing space. Sensor value used for actuating LED to ensure landing space visibility at night.

  Product Link

Actuators

• LED

  

  Product Link

Communication Method

• MQTT

  Between sink node server and station

• GPIO

  Between companion computer and sensors

Guide

• Run

  • type following command python3 run.py

• Packages

• GPS

  • Preparing

    1. install packages for GPS module.

       sudo apt-get update && sudo apt-get -y install gpsd gpsd-clients python-gps

       pip3 install gps

    2. Start the gpsd service and control it.

       Enable it: sudo systemctl enable gpsd.socket

       Start it: sudo systemctl start gpsd.socket

       Restart it: sudo systemctl restart gpsd.socket

       Check status: sudo systemctl status gpsd.socket

    3. Modify the configuration file of gpsd in /etc/default/gpsd Modify the "DEVICE" parameter according to the name of serial port in /dev folder. It is usually named "/dev/ttyUSB0" if you connect it to Raspberry Pi via USB cable. You can use "nano" or "vim.tiny" editor to finish it.

       

    4. Restart service: sudo systemctl restart gpsd.socket

       Finally, use this command to get information from GPS module. sudo cgps -s

• Camera

  • Preparing

    • Camset
      1. enable rasberry pi camera in sudo raspi-config
      2. sudo vim /etc/modules and add bcm2835-v4l2 below

    • opencv-python

      1. install dependent packages

      2. sudo apt-get update && sudo apt-get upgrade -y
         sudo apt-get install build-essential cmake pkg-config -y
         sudo apt-get install libjpeg-dev libtiff5-dev libjasper-dev libpng-dev -y
         sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev -y
         sudo apt-get install libxvidcore-dev libx264-dev -y
         sudo apt-get install libfontconfig1-dev libcairo2-dev -y
         sudo apt-get install libgdk-pixbuf2.0-dev libpango1.0-dev -y
         sudo apt-get install libgtk2.0-dev libgtk-3-dev -y
         sudo apt-get install libatlas-base-dev gfortran -y
         sudo apt-get install libhdf5-dev libhdf5-serial-dev libhdf5-103 -y
         sudo apt-get install libqtgui4 libqtwebkit4 libqt4-test python3-pyqt5 -y
         sudo apt-get install python3-dev -y
         

      3. install opencv-python with pip3

         sudo pip install opencv-contrib-python==4.1.0.25

    • apriltag

      cd Requirements/apriltag
      cmake .
      sudo make install
      

    • other packages

      pip install Cython
      pip install --upgrade imutils
      # Update pip
      python -m pip install -U pip
      # Install scikit-image
      python -m pip install -U scikit-image
      

  • Preparing

    • py-spidev

      cd py-spidev/
      sudo python setup.py install
      

• TempHumid Sensor

  • Prepareing

    • Adafruit_DHT

      sudo python3 -m pip install --upgrade pip setuptools wheel
      sudo pip3 install Adafruit_DHT
      

    • python board package

      pip3 install board

• MQTT client

  • mosquitto-client python

    sudo apt-get install build-essential libc-ares-dev uuid-dev libssl-dev libcurl4-openssl-dev libmysqlclient-dev
    sudo apt-get install mosquitto-clients
    pip3 install paho-mqtt
    

Reference Link

• Gps Wiki

• Raspberry Pi Camera Setting

• Opencv raspberry pi camera streaming

• LightSensor ADC setting

• mosquitto installation

• pqho-mqtt installation