I never really set out with the goal of roasting my own coffee beans, it just kind of happened.
It started a month ago when we got a coffee grinder. Naturally we started getting whole bean coffee, which we used at a rate of about one pound per week. While I’m not (by any standards) a coffee connoisseur, I found myself noticing that the first pot of coffee out of the new can really was just betterthan the last pot of coffee out of the old can– meaning that the coffee quality does actually decline noticeably after just a week.
Now, that’s a minor annoyance, and hardly cause for action. But, two weekends ago I happened to be browsing in a home brewing store (needed champagne yeast– that’s another story) where there were sealed bags of green coffee beans just sitting there on the shelf. Fair trade, organic, and in a number of varieites. Only 5 bucks a pound. So what the heck, right?
It turns out that there’s a common and cheap method of roasting coffee at home: using a regular air popcorn maker. You put the beans in the popper as though they were popcorn kernels, heat them for a few minutes until they’re properly roasted, and then cool them. (You can read the details of this process here, here, here, and here, amongst other places.) This is kind of neat because it doesn’t take much in the way of equipment and it roasts just enough for a big pot of coffee.
The weak point in the popper method is the cooling. The beans keep roasting as long as they are still hot, so many of the sites suggest pouring the beans back and forth between a couple of metal colanders until they cool down. We tried it, and while it did cool them faster than a cookie sheet, it was more tedious than fun. It also seemed a bit silly to use this nice semi-automatic roaster and then turn it over to a manual process for the next few minutes. So, here is our better (if somewhat obvious) solution: a dedicated coffee cooling tower, built from a second modified air popper. Continue reading Roasting coffee at home: a DIY coffee bean cooler
While trying to figure out what to do with about 75 pounds of fruit that our citrus trees bestowed upon us in January, we came across an interesting fact: marmalade is really easy to make. People of older generations may know this already, but so far as we knew, marmalade was one of those mysterious things that strictly comes from a jar. It turns out that all you need is citrus fruit, water, sugar and some time on the stovetop.
Question: What the heck is PONG supposed to be?
When you’re playing it, it feels like the video game representation of some real-life sport. You’re bouncing a ball back and forth with another player, which at first glance sounds a lot like like table tennis, AKA ping pong– and that would seem to explain the name. And yet, PONG is two-dimensional and free of gravity. The ball goes in a straight line, at a fairly constant rate of travel. And you don’t play ping pong by rotating a wheel. Come to think of it, it’s not a darned thing like ping pong. So what the heck is it?
To answer this important question, we built this real-life Tabletop Pong game.
Continue reading A playable game of Tabletop Pong
Some time ago, we wrote up a tutorial about using an ADXL330 accelerometer with an AVR microcontroller. A couple of years have passed, and so we’ve returned to update and clean up some loose ends on this project.
Continue reading Basics (updated): Using an accelerometer with an AVR microcontroller
Woo-hoo! We got a box of MakerBeam to keep us busy through the long dark winter evenings. For more info, see their kickstarter page, and the google group. They’ve been busy actually getting stuff made, so we’ll forgive them for not updating much lately.
The beam cross section is shown here with an LED for scale.
Come join us at the ComBots Cup at the San Mateo Fairgrounds on Saturday, December 19 and Sunday, December 20 from 2-7 pm. (Get tickets here.) And if taking your loved ones to see combat robotics wasn’t gift enough, you can do a little last minute holiday shopping without having to brave the mall! We’ll have a selection of kits (and a few robot repair parts) on hand. You can try out Meggy Jr RGB and see the new Bulbdial Clock in person.
Read more about the event at Suicide Bots. Special treat for our readers who attend: mention this post and we’ll give you an RGB LED in your choice of style. Hope to see you there!
Joyce and Kaufman sent in this truly fantastic Star Trek Pez LED menorah that they made. Joyce made it last year to hold candles, and this year Kaufman brought it right into the 24th 21st century by mind-melding modding it with one of our Deluxe LED Menorah kits.
Let’s give them both double credit for a fantastic job. Overengineering at its finest, this is.
