#growlab app for Raspberry Pi

Record a timelapse and live preview image with sensor data from a DHT22 temperature and humidity sensor.

The @alexellisuk growlab preview

Inspired by the Alex Ellis application

Assembling the build

• You'll need a Raspberry Pi Zero W or any other Raspberry Pi.
• A DHT22 sensor connected to GND, VCC SDL and SCL.
• An RPi camera connected - any version

Features [FR]

• Taking pictures at regular intervals
• Storage of photos for creation of a timelapse
• Use of a DHT22 sensor (temperature and humidity) to embed in the pictures
• Publish the last picture on a github page

Configuring the RPi

Using raspi-config

• Enable i2c under interfacing options
• Change the password for the pi user

Getting started with the software

Install git :

sudo apt update -qy && \
  sudo apt install -qy git\
  python3 \
  python3-pip \
  libopenjp2-7 \
  libopenjp2-7-dev \
  libopenjp2-tools

The libopenjp2 package is for overlaying text on top of the images.

Install the project

# clone project
git clone https://github.com/amouchere/growlab-project


# Get the roboto font
cd growlab-project
curl -sSL https://github.com/googlefonts/roboto/releases/download/v2.138/roboto-unhinted.zip -o roboto.zip
unzip roboto.zip -d roboto
rm roboto.zip

Install Python modules with pip3:

sudo pip3 install -r requirements.txt

Capture a test image to determine if you need a horizontal or vertical flip or not:

# On the RPi
raspistill -o growlab.jpg

If needed, test again with -vf or -hf to flip the image.

Edit the config.json (flip if needed, preview repository path ..)

{
    "time": {
        "interval_seconds": 600,
        "start": 8,
        "end": 20
    },
    "preview":{
        "git_dir":"/home/pi/growlab-preview",
        "git_path":"git@github.com:<>Your github here/growlab-preview.git"
    },
    "images": {
        "output_directory": "/home/pi/timelapse/",
        "encoding": "jpeg",
        "width": 2592,
        "height": 1944,
        "image_quality": 100,
        "preview_seconds": 1,
        "vertical_flip": true,
        "horizontal_flip": false,
        "meter_mode": "matrix"
    },
    "text": {
        "colour": {
            "red": 100,
            "green": 255,
            "blue": 100
        },
        "size": 52
    }
}

Test the code:

python3 app.py

Serve a preview with GitHub pages

Configure GitHub pages in your own repo

Set the folder for serving content to "root"

Install the service

sudo cp ~/growlab-project/growlab-project.service /etc/systemd/system/growlab-project.service
sudo systemctl enable growlab-project.service
sudo systemctl start growlab-project.service

Hardware

Some pictures of my growlab installation.

• Reclaimed wood
• Raspberry pi V2 with Wifi USB Stick
• PI Camera
• Temparature and Humidity sensor (DHT22)
• On/Off Button for shutdown the PI without opening an ssh session

The wood structure

The growlab

A view from below with the camera and the DHT22 sensor