Meeting Light Prototype

This project was created during COVID-19 when I was working at home. Being in many meetings each day, I wanted a physidig way to let my husband know when I was in a meeting. I decided to take my calendar (via the Google Calendar API) and map my free/busy periods to an LED output (green for free, red for busy/in meeting).

This project was created as part of the experiential research the physidig team conducted as part of our capstone project.

As a note, the main project is located in the app/ directory. In the prototype_scripts/ directory, you'll find some other scripts I used to get started and test out my board with pyfirmata.

Getting started for /app (the main project)

Required materials

• Arduino Uno
• Solderless breadboard
• 3 male-to-male jumper wires
• Two LEDs (one red and one green)
• Two 220 ohm resistors
• USB A to USB B cord

Arduino Setup

• Plug in your Arduino Uno to your machine using the USB A to USB B cord
• Launch the Arduino IDE software (note that I built this on MacOS Catalina)
• Configure your board and port via Top Menu Bar > Tools > Board > Select Arduino Uno and Tools > Port > some serial bus port (mine was 1420)
• Because I've opted to write the interface in Python (Firmata protocol via pyfirmata client), we need to load the StandardFirmata code example via File > Examples > Firmata > StandardFirmata
• Compile and load this example onto your Arduino Uno

Great, now your board is ready to run the Python Firmata client - pyfirmata!

• Unplug your board from your machine to cut power
• Assemble this circuit insert schematic here
• Plug your board back in

Google Calendar API Setup

• Go to the Google Calendar API Python Quickstart
• Click Enable Google Calendar API (note that you need a Google account)
  • This will open a module and download a credentials.json file which you should copy into the root directory of the project

Code Setup

Install Required Packages

• Open this repo in your editor/IDE of choice (I like Visual Studio Code ;) )
• Select Python 3.7 as your interpreter
• Create a virtual environment via python3 -m venv venv via the terminal within the root directory of the project
• Install the requirements.txt via pip install -r requirements.txt to install required Python packages

Configure your calendar

• Create a file called calendar_id.py in the /app directory with a constant called CAL_ID
• Go to your Google Calendar
• Find a calendar you want to use
• Click the Options (the three dots beside the calendar name) > Settings
• Scroll to 'Integrate Calendar' and copy the ID (your default calendar ID is 'primary')
• Paste this ID as the value for your CAL_ID constant
• Open the app/get_calendar_events.py and run it
• In the terminal, you should see a Google link
• Click the link to authenticate in the browser. Once you've done this, the browser will tell you that you can close the window
• Go back to your editor/terminal and verify that there are no other errors

Running the script

• Go to /app/hardware_interface.py
• Replace the port in the board=pyfirmata.Arduino('/dev/cu.usbserial-1420') line if your port is not 1420
• Run this file and you should now see one of your LEDs light up on your board (red if your calendar says you are in a meeting and green if you are free)
  • You can test this by creating a new meeting on your Google calendar and verify that LEDs switch