Raspberry Pi Terminal Hub

Turning a RPi into a server hub using Raspian OS Lite.

Credits: Icons created by @erikflowers

The main.go file contains the primary logic of continuously running the code. It handles starting and stopping the various underlying services.

NOTE: PWM usage requires root privleges

Configuration

• --owm: For passing in the OpenWeatherMap api key. This can also be passed via an OWM environment variable
• Configuration of variables in the code can be done via -ldflags

go run -ldflags "-X github.com/aalu1418/rpi-terminal-hub/types.WEATHER_LOCATION=hello" main.go

• build + upload to RPi commands (using SSH)

env GOOS=linux GOARCH=arm GOARM=5 go build
scp rpi-terminal-hub pi@<rpi-ip>:/home/pi/

Modules

Various integrations for controlling / reporting devices and information.

[service] Web Server

The web server module provides an user facing endpoint for the weather panel, controlling the vacuum, and prometheus metrics host.

• GET /: Main endpoint with a stylized HTML page for weather
• POST /vacuum: Used for triggering the IR emitter to issue vacuum commands (start, stop, 30min, home)

curl -X POST -d "start" localhost:5000/vacuum

• GET /metrics: prometheus metrics endpoint

[service] Weather

The weather service polls the OpenWeatherMap API for weather data and provides it in a consumable form to the Web Server.

Learn more here: https://openweathermap.org/api

[service] Vacuum

Uses the IR emitter to control the robotic vacuum and issue commands on a set schedule.

Original inspiration (actual circuit is slightly different): https://www.hackster.io/austin-stanton/creating-a-raspberry-pi-universal-remote-with-lirc-2fd581

[service] Alerts

Polling and parsing various endpoints to monitor for alerts. Currently supported:

• NOAA/NWS weather alerts for given LAT/LON

[service] Connectivity

Polling a DNS service to determine internet connectivity. Information is reported to the metrics service.

[service] Metrics

Handles various incoming messages from other services and tracks accordingly using prometheus metrics.

Exporting to Grafana: https://grafana.com/oss/prometheus/exporters/node-exporter/

[service] Post Office

Message router for the various services to communicate.

[service] Base

Underlying service that provides base functionality for each services incoming and outgoing messages, frequency of processing, etc.

[GPIO] Infrared

Provides basic utilities for recording and emitting IR PWM signals

• --emit-ir: flag for testing an IR signal
• --record-ir: flag for recording an IR signal, prints out golang formatted time durations

Notes

Setting up SSH on RPi

• https://www.tomshardware.com/reviews/raspberry-pi-headless-setup-how-to,6028.html

Autorun on RPi using CRON

• https://phoenixnap.com/kb/crontab-reboot
• Included a delay to allow internet connection to be established

@reboot sleep 15 && sudo /home/pi/rpi-terminal-hub --owm=<API_KEY> >> ~/cron.log 2>&1

RPi Timezones

• https://raspberrypi.stackexchange.com/questions/87164/setting-timezone-non-interactively

Server Inspiration

• https://shkspr.mobi/blog/2020/02/turn-an-old-ereader-into-an-information-screen-nook-str/
• completed look: