AquaBot

The AquaBot project aims to provide a set of tools, to configure and operate a cloud native aquaponics monitoring system. The monitoring system requires, a raspberry pi for collecting metrics from an aquaponics system, and a monitoring workstation to view and analyze the metrics. an AWS account for long term metrics storage is also required. The setup instructions for each of these components, especially the AWS section, are currently incomplete.

The raspberry pi is configured to read from attached sensors, and send their readings to an AWS IOT Gateway, via MQTT messages. Once the MQTT messages hit the AWS IOT Gateway, a rule writes the reading to a DynamoDB table.

The goal of the AWS account portion of this project, is to store aquaponics system metrics on serverless cloud based infrastructure, that can be run using the AWS Free Tier, and stood up in an automated fashion.

The monitoring workstation runs a set of docker containers, which include Grafana, InfluxDB, and Importer. Grafana provides a local monitoring platform, accessible through a web browser. InfluxDB is used to store a continually updating local mirror of the metrics stored in DynamoDB. The Importer is purpose build for the AquaBot project. It continually updates InfluxDB with metrics pulled from DynamoDB.

Setting up your raspberry pi

The raspberry pi for this project should be setup to use the raspbian operating system.

The following additional steps should also be taken:

• run sudo raspi-config, and turn on the One-Wire Interface
• append dtoverlay=w1-gpio,gpiopin=4 to /boot/config.txt
• run sudo modprobe w1–gpio
• reboot the system (you might need to run this step between each of the above steps)
• set up passwordless ssh with ssh keys
  • create an ssh key on the monitoring station
    • ssh-keygen -f ./AquaBot/rsync/ssh/id_rsa
  • copy the public key to ~/.ssh/authorized_keys on the raspberrypi
• run some commands
  • pip install influxdb influx_line_protocol
  • `sudo cp pi/systemd/aquabot.service /lib/systemd/system/``
  • sudo systemctl daemon-reload
  • sudo systemctl enable aquabot.service
  • sudo su
  • apt-get update
  • apt-get unstall pip
  • pip install influx influx_line_protocol
  • reboot
• clone the AquaBot repository into a ~/Workshop directory
• setup a cron job to pull changes to this repository
  • add a new ssh key in github for the new aquabot
  • run ( crontab -l && printf -- 'echo * * * * * /home/pi/Workshop/AquaBot/cron-gitops.sh >> ~/.aquabot-gitops.log\n' ) | crontab
  • this cron job also create and pushes git tags with status updates

Setting up your monitoring station (example uses arch linux package manager)

Installing docker

sudo pacman -S docker-compose
sudo usermod -aG docker $USER
sudo systemctl enable docker
sudo systemctl start docker
systemctl status docker.service

Installing python packages

pip install influx_line_protocol

Temperature sensor python script

The temperature sensor script reads the output of the temperature sensor on the GPIO pins, and writes the output to stdout.

It can be run using the following command.

It will output logs to ./logs/temperature.log

Importer-InfluxDB-Graphana Stack (IIG Stack)

This project originally used a TIG Stack (Telegraf-InfluxDB-Graphana Stack), but the Telegraf component did not come to fruition. Instead an importer written in python is used to copy data from DynamoDB to the local InfluxDB database.

The importer copies up to 5000 datapoints every 5 seconds. This use close to 87.0 amazon read credits. AWS Free Tier allows for 25 amazon read credits every second. After a bit of math, the importer falls within the Free Tier range.

Grafana Dashboard

A pre-build dashboard can be imported through the Grafana UI. The dashboard filepath is grafana/aquabot-dashboard.json.

Wiring Diagram

An equivalent diagram can be found here.