Alarm Notifies The Office When The Coffee Is Ready

[Stian] thought it would be nice if his coworkers could be electronically notified when the latest batch of coffee is ready. He ended up building an inexpensive coffee alarm system to do exactly that. When the coffee is done, the brewer can press a giant button to notify the rest of the office that it’s time for a cuppa joe.

[Stian’s] first project requirement was to activate the system using a big physical button. He chose a button from Sparkfun, although he ended up modifying it to better suit his needs. The original button came with a single LED built-in. This wasn’t enough for [Stian], so he added two more LEDs. All three LEDs are driven by a ULN2003A NPN transistor array. Now he can flash them in sequence to make a simple animation.

This momentary push button supplies power to a ESP8266 microcontroller using a soft latch power switch. When the momentary switch is pressed, it supplies power to the latch. The latch then powers up the main circuit and continues supplying power even when the push button is released. The reason for this power trickery is to conserve power from the 18650 li-on battery.

The core functionality of the alarm uses a combination of physical hardware and two cloud-based services. The ESP8266 was chosen because it includes a built-in WiFi chip and it only costs five dollars. The microcontroller is configured to connect to the WiFi network with the push of a button. The device also monitors the giant alarm button.

When the button is pressed, it sends an HTTP request to a custom clojure app running on a cloud service called Heroku. The clojure app then stores brewing information in a database and sends a notification to the Slack cloud service. Slack is a sort of project management app that allows multiple users to work on projects and communicate easier over the internet. [Stian] has tapped into it in order to send the actual text notification to his coworkers to let them know that the coffee is ready. Be sure to watch the demo video below.

12 thoughts on “Alarm Notifies The Office When The Coffee Is Ready

  1. cloud? really? and two of them?

    I has a sad ;(

    I just don’t get the embrace of doing things over a public wan that don’t need to go over a public wan, much less several public websites.

  2. Mr. Goldberg would be proud.
    Some things need to be scheduled, you just know when it’s time.
    I prefer a Melita cone under a no longer pod equipped pod style maker. Pushbutton convenience with low waste and one perfect cup. Turnaround time with this setup is 1 or 2 minutes.

  3. Eh. It’s okay. Needs more automation. Machine needs to automatically fill, coffee grounds need to automatically change itself, and should automatically detect when coffee pot is empty, and make a new batch. Or that’s what I would like to see. I need to submit my Keurig that never empties.

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