Coffee Maker Mod

Sure… anyone can go to the local store and buy a coffee maker with a timer. That was not good enough for our new member Ryan Merl.  Keeping in the hacking spirit, Ryan decided to make his own internet controlled coffee maker. He installed a relay between the wall cord and the power switch on the coffee pot. The relay is controlled by his arduino. He used this tutorial as a guide.  An ethernet shield is used to connect the arduino to the network.

You can find the source code for this project here: Be sure to checkout the Readme.doc for more details.

Special Features

  • 15 minute automatic shutoff
  • Controlled via HTTP Requests
  • Status, start, and stop requests
  • Returns JSON meant for AJAX interfaces
  • Ready and running LEDs

HTTPCoffeePot can be connected to your arduino with an ethernet shield and attached to the network. It will listen on port 80, like a normal web server, and take several different request URLs to control it. The URLs return JSON with the intention that an AJAX interface will be built over it:

  • /status/ – This will return some information about the current status of the coffee pot
  • /start/ – This will start the coffee pot assuming that it is currently ready to be started and not started already
  • /stop/ – This will turn off the coffee pot

Currently the process will work like this:

  1. Put in coffee grounds/filter/water
  2. Press ready button to enter coffee pot into ready state
  3. When coffee is desired, send /start/ request
  4. Wait for coffee to finish
  5. Send manual /stop/ request OR wait for timed automatic shut off to take place after 15 minutes

I have a very simple coffee maker which is really only a switch. The modifications I made to the pot were to cut the power inside of it between the wall and the switch on the pot and place a relay in between. The relay is then activated by the Arduino board when sent the /start/ request.

Useful wireless solution comparison chart

Last week I was having a discussion with one of our members about solutions on how we can control his biped robot he is working on.  I was trying to explain that we could go something like zigbee (which he has a zigbee servo controller already) but you’re going to trade off throughput, if you wanted to add streaming video to it, and we’ll need to construct something for the pc to talk to the zigbee network.  We could go bluetooth, or even wifi, etc.  And it became a discussion of push pull’s difficulty implementing it, writing code for, cost of parts, etc.

(Biped robot pictured below if you havent’ seen it, it’s really awesome!)










Anyway, I stumbled on this article on digikey’s web site that goes into further detail, but I wanted to share this nice little chart they have in the article.  It really sums up cost vs range vs throughput vs robustness.  I found it useful, thought someone else might also.  Enjoy.