snweatherstation 1.2.1

Another Raspberry Pi Weatherstation

snweatherstation

Another weather station for Raspberry Pi, logging temperature, humidity and pressure in a database table or to a file. If configured, also foracast data from https://openweathermap.org/ are logged in the database.

A web application is available to visualize measured data together with historical and forecast data.

Getting started

Step	Action
1.	Install snweatherstation ([sudo] pip install snweatherstation)
2.	Connect the chosen sensor to the Raspberry Pi GPIO pins (see Supported Sensor Types)
3.	Create a new MariaDB database or select an available one (see MariaDB below)
4.	Create table for weather data (see Database Schema Setup)
5.	If forecast data are intended, create also the database tables for forecast data
6.	Stage and configure the configuration file (see Configuration)
7.	Do a test run (see Usage)
8.	Set up Weatherstation service (see Configure Weatherstation Service)

Usage

usage: weatherstation.py [-h] [-t] [-s] [-l] [-L] [-F] [-f FILE] [-v]
                         [-c CONFIG]

    This program periodically reads environment sensor data
    and stores these either in the database and/or in a file and/or just prints measured values.

    If not otherwise specified on the command line, a configuration file
       weatherstation.json
    will be searched under $HOME/.config or under /etc.

    This configuration file specifies the database connection and other runtime parameters.


optional arguments:
  -h, --help            show this help message and exit
  -t, --test            Test run - single cycle - no wait
  -s, --service         Run as service - special logging
  -l, --log             Shallow (module) logging
  -L, --Log             Deep logging
  -F, --Full            Full logging
  -f FILE, --file FILE  Logging configuration from specified JSON dictionary file
  -v, --verbose         Verbose - log INFO level
  -c CONFIG, --config CONFIG
                        Path to config file to be used

Configuration

Configuration for weatherstation needs to be provided in a specific configuration file. By default, a configuration file "weatherstation.json" is searched under $HOME/.config or under /etc.

For testing in a development environment, primarily the location ../tests/data is searched for a configuration file.

Alternatively, the path to the configuration file can be specified on the command line.

Inclusion of weatherforecast data

weatherstation can record foracast data for the geographic position of the weather station in order to be visualized together with measured data. Currently, only the service from https://openweathermap.org/ is supported. In order to be able to request data from this site, it is necessary to create an account (which is free) and to generate an API key. The service is free for a limited number of requests (60) per second, which will never be exceeded by weatherstation.

Structure of JSON Configuration File

The following is an example of a configuration file:

{
    "sensorType": "DHT22",
    "raspiPin": "PIN13",
    "measurementInterval": 900,
    "dbOut": true,
    "fileOut": false,
    "includeForecast": true,
    "dbConnection":
    {
        "host": "localhost", 
        "port": 3307, 
        "database": "weather", 
        "table": "weatherdata",
        "user": "testuser", 
        "password": "$[TestUser-1]@?"
    },
    "fileName": "weatherData.txt",
    "forecast":
    {
        "source":
        {
            "url": "https://api.openweathermap.org/data/2.5/onecall",
            "payload":
            {
                "lat"   : "54.188055",
                "lon"   : "7.869444",
                "units" : "metric",
                "lang"  : "de",
                "appid" : "xxxxx"
            }
        },
        "height": 226,
        "forecastDbOut": true,
        "forecastFileOut": false,
        "forecastTables":
        {
            "hourlyForecast": "weatherforecast",
            "dailyForecast" : "dailyforecast",
            "alertsForecast": "alerts"
        },
        "forecastFile": "forecastData.txt"
    }
}

Parameters

Parameter	Description	Mandatory
sensorType	Type of the environment sensor (see supported sensor types, below)	Yes
raspiPin	Raspberry Pi GPIO pin in BOARD notation used for data signal, if required	See SesorType
measurementInterval	Measurement interval in seconds.	Yes
dbOut	Specifies whether measured values shall be stored in the database (true, false)	Yes
fileOut	Specifies whether measured values shall be written to the specified file (true, false)	Yes
includeForecast	Specifies whether forecast data shall be tracked (true, false)	Yes
dbConnection	Database connection parameters	For dbOut=true
- host	Host name or IP address of database server	Yes
- port	Port for MariaDB service	Yes
- database	Name of the database where data shall be stored	Yes
- table	Name of database table where data shall be stored	Yes
- user	Database user	Yes
- password	Password for database user	Yes
fileName	Path to file to which data shall be written (optional)	For fileOut=true
forecast	Parameters for forecast	For includeForecast=true
- source	Parameters for forecast source	Yes
-- url	URL of forecast service provider (currently only https://openweathermap.org/)	No
-- payload	Service call parameters	Yes
--- lat	Geographical coordinates of the location of the weatherstation (latitude)	Yes
--- lon	Geographical coordinates of the location of the weatherstation (longitude)	Yes
--- units	Units in which to return data ('metric' or 'imperial')	No
--- lang	valid language code for language specific data (default: 'de')	No
--- appid	Your unique API key (https://openweathermap.org/ account page under "API key" tab)	Yes
-- height	Height of weatherstation above sea level (for barometric formula)	Yes
-- forecastDbOut	If foracast data shall be stored in the database (true, false)	Yes
-- forecastFileOut	If forecast data shall be written to file (true, false)	Yes
-- forecastTables	Table names for forecast data	For forecastDbOut=true
--- hourlyForecast	Table name for hourly forecast	Yes
--- dailyForecast	Table name for daily forecast	Yes
--- alertsForecast	Table name for alerts	Yes
-- forecastFile	Path to file for forecast data. File output is JSON as received from weather service	For forecastFileOut=true

Supported Sensor Types

See also https://github.com/signag/snraspi-lib/blob/main/docs/EnvironmentSensors.md

SensorType	Description	Measured Data	Raspi bus	raspiPin
DHT11	DHT11	temperature, humidity	1-Wire	1-Wire pin
DHT22	DHT22	temperature, humidity	1-Wire	1-Wire pin
BME280_I2C	BME280	temperature, humidity, pressure	I2C	--
BMP280_SPI	BME280	temperature, humidity, pressure	SPI	Chip Select

MariaDB

weatherstation stores weather data in a MariaDB database (see https://mariadb.org/).

MariaDB is available on Linux and Windows platforms. A MariaDB server is also provided as plugin on most of the popular NAS systems. For weatherstation, you may use any of your available MariaDB servers, as long as it is visible to your Raspberry Pi.

Alternatively, you may also install a MariaDB server on your Raspberry Pi.

NOTE MariaDB Client and connectors are installed together with weatherstation.

Setup MariaDB Server on Raspberry Pi

INFO Skip this step if you will be using an existing MariaDB server

Installation

sudo apt install mariadb-server php-mysql
sudo apt install phpmyadmin

Service configuration

For automatic start:

sudo systemctl enable mariadb

For manual start:

sudo systemctl disable mariadb

sudo systemctl start mariadb
sudo systemctl stop mariadb

Database Schema Setup

weatherstation requires a database table with a specific structure. For forecast data, two additional tables are required.

An SQL script template is available under ./data: createDBtable.sql in the installation folder.

The table names can be adjusted in the script and configured in the weatherstation config file so that different tables can be used to distinguish different physical weather stations in the same database.

Run this SQL script against the database to create the required database table(s).

Configure Weatherstation Service

To continuously log weather data, weatherstation should be run as service.

See https://www.raspberrypi.org/documentation/linux/usage/systemd.md

A service configuration file template can be found under ./data in the installation folder.