# README

weather

Raspberry Pi weather station

A simple weather station based on a raspberry pi. It used a BME280 sensor for pressure and humidity and some generic weather station parts for the rain guage, wind speed and wind direction sensors. I'm using a MCP9808 for temp as I found the BMEwas off by 0.5C

MCP9806 has a typical accuracy of 0.25C and a max error or 0.5C https://ww1.microchip.com/downloads/en/DeviceDoc/25095A.pdf

It's written in go which is each to cross compile for the pi.

I use a prometheus time series database to scrape and record the values. These are displayed on a grafana dashboard. It's served from my home server using nginx reverse proxy.

Below are just notes and common commands (easier to cut and paste than to type out each time!)

MetOffice

The UK Met Office run an observation site for users to submit thier own data.

https://wow.metoffice.gov.uk

We send data to the Met Office if the two relevent env variables are set:

WOWSITEID The site ID WOWPIN The site PIN SENDWOWDATA=true SENDPROMDATA=true

Pi setup

Use raspi-config to enable ssh and i2c

compilation

env GOARCH=arm GOARM=5 GOOS=linux go build -o weatherServer.exe

transfer and logs

scp weatherServer.exe [email protected]:/home/pi

journalctl -f -e -u weather.service

service file

[Unit]
Description=Weather monitor service
After=network.target
StartLimitIntervalSec=0
StartLimitBurst=5

[Service]
Type=simple
Restart=always
RestartSec=1
User=root
Environment=SENDWOWDATA=true
Environment=SENDPROMDATA=true
Environment=WOWSITEID=aaa-bbb-ccc-ddd-eee-fff
Environment=WOWPIN=0123456789
ExecStart=/usr/local/bin/weatherServer.exe
ExecStartPre=/bin/sh -c "cp -f /home/pi/weatherServer.exe /usr/local/bin"

[Install]
WantedBy=multi-user.target

prometeus

chgrp -R nogroup /prometheus

docker run -d --name prometheus_weather -p 9090:9090 -v /prometheus/config/prometheus.yml:/etc/prometheus/prometheus.yml -v /prometheus/data:/prometheus prom/prometheus --config.file=/etc/prometheus/prometheus.yml


global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
  - static_configs:
    - targets:
      # - alertmanager:9093

# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  # - job_name: 'prometheus'
    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.
  #  static_configs:
  #  - targets: ['localhost:9090']
  - job_name: weather
    scrape_interval: 30s
    static_configs:
    - targets:
       # change to match weather station ip
      - 192.168.1.202:80
  - job_name: river
    scrape_interval: 30s
    static_configs:
    - targets:
      - localhost:50000