I've been interested in the idea of hacking a coffee maker to connect it to the google assistant for a while now and thought it was time to give it a try. The idea is that you can say a command to the google assistant (on your phone, Google Home, etc) and that would trigger the coffee maker to start brewing a cup of coffee.
I took inspiration from two sources, an instructable on how to make a Keurig machine auto-brew coffee, and a part of YouTube series about using controlling a laser-pointer turret with google assistant.
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Step 1: Supplies
I used the following supplies and tools. You can make substitutions for some based on what you have access to.
1. Coffee maker (mine was ~ $15 at Walmart, it brews k-cups)
2. Raspberry Pi (mine is a version 3 model B, but as long as it is able to connect to the internet it should be fine)
a. HDMI cable
b. USB to micro USB cable and USB wall plug
c. Monitor for Raspberry Pi
3. Micro SD card (to load the raspberry Pi OS)
4. Jumper wires
7. Soldering iron
9. Multi meter
10. Rotary tool (some way to cut into the casing of the coffer maker to access the PCB)
12. Adafruit IO account (see the linked video in the Introduction, at 4:15, for setup)
12. Coffee supplies
a. Coffee cup
b. Test coffee (in my case k-cups)
Step 2: Assembly
First I cut open the coffee maker to expose the PCB under the brewing buttons. I then located the button for the brewing setting that I wanted. I tried to use a multi-meter to determine the current that was needed to trigger the brewing process after the button was pressed. Then I soldered two wires to the button contacts, and connected them up to the breadboard.
NOTE: Be sure to have water in the reservoir and a cup under the nozzle to catch the hot water before pressing the brew button
NOTE: My coffee maker's on button and brew button are the same which caused problems for me soon after this step
Step 3: Writing the Code, Setting Up Google Assistant
For this portion of the project I borrowed heavily from the YouTube video in the introduction. The you-tuber has uploaded all of his code to GitHub which I then modified to fit my needs. He also gives detailed instructions on how to setup the IFTTT app and link it to your Adafruit IO feed. He also shows how to create and export hte OS for the raspberry pi. The last two pictures above show my settings for the IFTTT applet. Below is the GitHub repository for my project, please reference the readme for descriptions of what each file does. The idea is that the google assistant can change the value of the feed through the IFTTT applet. The raspberry pi should then listen for the change, and once it 'hears' it will trigger the brew button on the coffee maker
NOTE: my code is bugged, and doesn't read changes to the Adafruit IO feed ad of 10/26/18
GitHub Repository: https://github.com/spartan405/googleCoffee
Step 4: Murphy's Law Strikes
After multiple tests with the IFTTT applet version not working, I decided to just get the coffee maker to brew after sending a command through the raspberry pi. I had just gotten the new code onto my Pi and was about to test it when the two wires I had soldered to the button on the coffee maker both touched pins on my Pi. This resulted in a completed circuit directly through my raspberry pi, which fried my pi killing it outright. Until I can get a new one, this project has been put on hold.
When I come back to this, I plan to solve the bugs in the code so that it will work with the google assistant.