app

#growlab app for Raspberry Pi

Record a timelapse and live preview image with sensor data from a Bosch BME280 temperature, humidity and air pressure sensor.

Example HTML output which can be synced to GitHub Pages, an S3 bucket, or served directly from the RPi using inlets

See also: app roadmap

Assembling the build

• You'll need a Raspberry Pi Zero W or any other Raspberry Pi.
• A BME280 sensor connected to GND, VCC SDL and SCL.
• An RPi camera connected - any version

Configuring the RPi

Using raspi-config

• Set your hostname such as growpi
• Enable i2c under interfacing options
• Change the password for the pi user

Getting started with the software

Install git and tmux:

sudo apt update -qy && \
  sudo apt install -qy git tmux

Clone the repo:

git clone https://github.com/alexellis/growlab
cd growlab/app

Get the roboto font:

curl -sSL https://github.com/googlefonts/roboto/releases/download/v2.138/roboto-unhinted.zip -o roboto.zip
unzip roboto.zip -d roboto

Install apt packages:

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

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

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

# From your PC:
scp pi@growlab.local:~/growlab.jpg Desktop/

# On a Mac:
open Desktop/growlab.jpg

# On a Linux desktop:
xdg-open Desktop/growlab.jpg

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

Edit the config.json file if needed and update the flip settings, and width and height to match the file that you got from your test growlab.jpg image.

{
    "images": {
        "output_dir": "./images/",
        "encoding": "jpeg",
        "width": 2592,
        "height": 1944,
        "image_quality": 70,
        "preview_seconds": 1,
        "vertical_flip": false,
        "horizontal_flip": false,
        "interval_seconds": 600
    },
    "text": {
        "colour": {
            "red": 255,
            "green": 255,
            "blue": 255
        },
        "size": 48
    }
}

Test the code:

python3 app.py

Serve a preview with GitHub pages

Configure GitHub pages and / or a custom domain using the CNAME approach

Set the folder for serving content to "docs"

Generate an SSH key:

cd growlab/app
mkdir -p .ssh

ssh-keygen -f `pwd`/.ssh/id_rsa

Remove the HTTPS git remote and add a SSH one, changing "alexellis" to your own name.

git remote rm origin
git remote add origin git@github.com:alexellis/growlab.git

Go to the repo settings and add the deploy key and check Allow write access

Now run the sample.sh bash script. Feel free to view its contents to see how it works

cd growlab/app

./sample.sh

You can also put this into a loop to run every 10 minutes:

while [ true ] ; do ./sample.sh && echo "waiting 10 minutes" && sleep 600 ; done 

Install growlab as a service

Install the systemd service:

touch /etc/default/growlab
sudo cp growlab.service /etc/systemd/system
sudo systemctl enable growlab
sudo systemctl start growlab