d3473r / rsc-2019-weather-station

A Weather Station implementation for the 1st Undergraduate Robotic Sailing Challenge 2019

rsc-2019-weather-station

A Weather Station implementation for the 1st Undergraduate Robotic Sailing Challenge 2019

Table of contents

• Components
• Requirements
• Installation
• Running
• Usage
• Autostart
• Data
• Demo

Components

Weather station

SparkFun Electronics SEN-08942

Data sheet

PCB

The Gerber files are in the pcb directory

The pcb design is here: https://easyeda.com/D3473R/weather-station

Wifi Adapter

Alfa Network AWUS036NHA

Wifi Adapter Bracket

You will need 2 M3 screws with min. 15mm length and two nuts

Side 1

Wifi_Adapter_Bracket_20mm_Side_1.stl

Side 2

Wifi_Adapter_Bracket_20mm_Side_2.stl

Requirements

Update packages

• sudo apt update
• sudo apt install python3-dev

pipenv

• Remove pip from apt as it may collide with pip installed from pipenv sudo apt remove python-pip
• Install pipenv curl https://raw.githubusercontent.com/kennethreitz/pipenv/master/get-pipenv.py | sudo python

git

• Install git with sudo apt install git-core

mosquitto

• Install mosquitto with sudo apt-get install -y mosquitto

Installation

• Clone the repository with git clone https://github.com/D3473R/rsc-2019-weather-station.git
• Navigate in the cloned directory with cd rsc-2019-weather-station
• Install the python dependencies with pipenv install

Running

• Start a pipenv shell with pipenv shell
• Run weather.py with python src/weather.py

To receive the data on another machine you can use any MQTT Client, e.g. mqttfx.

Simply connect to the ip of the raspberry and subscribe to the channel weather

To receive the data in python you can also use paho-mqtt

Usage

usage: weather.py [-h] [--server MQTT_SERVER] [--path MQTT_PATH]
                  [--speed SPEED_PIN] [--dir-error DIRECTION_ERROR]
                  [--dir-prec DIRECTION_PRECISION] [--send-sleep SEND_SLEEP]
                  [--chart]

optional arguments:
  -h, --help            show this help message and exit
  --server MQTT_SERVER, -s MQTT_SERVER
                        the ip of the mqtt server (default: localhost)
  --path MQTT_PATH, -p MQTT_PATH
                        the path of mqtt packets (default: weather)
  --speed SPEED_PIN     the gpio pin which is connected to the wind speed
                        sensor (default: 25)
  --dir-error DIRECTION_ERROR
                        the direction value that will be written if an invalid
                        direction was read (default: 359)
  --dir-prec DIRECTION_PRECISION
                        the precision in Volts of the mapped direction values
                        (default: 0.015)
  --send-sleep SEND_SLEEP
                        the time in seconds between two mqtt packets (default:
                        0.2)
  --chart, -c           enable asciichartpy (default: False)

Autostart

Autostart of the weather station can be accomplished via systemd.

Create a service file:

sudo nano /etc/systemd/system/weather-station.service

And enter the following:

Unit]
Description=Weather Station Service
After=network.target

[Service]
User=pi
Restart=always
Type=simple
WorkingDirectory=/home/pi/rsc-2019-weather-station/
ExecStart=/usr/local/bin/pipenv run python /home/pi/rsc-2019-weather-station/src/weather.py

[Install]
WantedBy=multi-user.target

Reload the systemd daemon with:

sudo systemctl daemon-reload

Start the service with:

sudo systemctl start weather-station

If you want the weather station to start on boot enter:

sudo systemctl enable weather-station

Data

A JSON packet consists of the timestamp the packet was sent, the wind direction in degrees (in 16 steps) and the wind speed in m/s.

{"timestamp": "2019-02-13T15:01:13Z", "direction": 67.5, "speed": 4.32}

Demo