Keep Your Kids In Line With A Time Clock

December 19, 2010 by Mike Szczys 68 Comments

When the cat’s away the mice will play, but a least you’ll know when they came home if you use this time clock. It’s called the Kid-e-log and [John Boxall] developed it to help a friend who wanted to keep track of their teenage children’s after school activities while they were still at work. He figured having them punch a time clock would at least let you know if they came straight home as they were supposed to. An RFID tag was issued to each (no, they didn’t implant the tags) and used to record the time. To keep fraud to a minimum the hardware has a battery back-up for its real-time clock, and the tag read events are stored to EEPROM for retention between power cycles. This doesn’t prevent common tricks like taking the reader with you, or sending your tag with a sibling, but it’s a start. See it in action after the break.

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Bluetooth Temperature Module

December 10, 2010 by Mike Szczys 11 Comments

Wanting to know the outside temperature, [Jamie Maloway] built his own temperature sensor that can be read with a Bluetooth device. Let’s take a tour of the hardware above from right to left. There’s a linear voltage regulator with two filtering caps and a terminal block to attach a 9V battery or other power source. Next there’s an 8 MHz crystal and it’s capacitors, followed by a programming header on top and a 1-wire temperature IC, the DS18B20 we’re all familiar with hanging off the bottom. These both connect to the 8-pin PIC 12F675 that drives the system, and transmits using a Bluetooth module from Sure Electronics. Since this is using a serial protocol and transmitting ASCII data, it can be read using an automated script, or simply by using a terminal program.

Now, who’s going to be the first to get rid of the battery and leech off of the mains through inductance?

Home Brew Coffee Machine

December 8, 2010 by Joseph Thibodeau 23 Comments

There are already a lot of different ways to brew up a decent coffee at home, from the humble saucepan to the elegant vacuum flask. In an office environment the choice of coffee-making technique can have a major impact on workplace harmony—how can people be expected to work happily when the kitchen is filthy with grounds and the coffee is always stale? “Someone have mercy,” [Christian Finger] lamented, “and boil a pot of fresh.”

In the end he took extreme measures, building a machine that grinds whole beans, measures out a dose, brews a cup and self-cleans. He used all sorts of odds and ends to put the thing together, detailed in his long and hilarious build log (english translation—and check out the dude’s sweet ride). Refer to his shockwave animation for a summary of the intended operation.

The end result is an extremely impressive Goldbergian contraption—download the video from the build log. It is pretty noisy and probably energy- and water-hungry, but that wouldn’t stop us from using it every day, if given the chance. Hell, this here could form a major part of your next breakfast machine.

We’re sure that there is further potential in this, because to get the really freshest possible cup of coffee you’d want to roast the coffee beans just before grinding them. Then you’d be well on your way towards something else entirely: a delicious breakfast machine.

Christmas Tree Low-water Monitor

December 8, 2010 by Mike Szczys 24 Comments

The end of the year is rapidly approaching and there’s a good chance you have a slowly dying tree in your living room. Help it hold on a little longer by using [Eric Ayars’] Christmas Tree water monitor. He’s built a sensor out of a piece of strip board. Three bus strips on the board allow for a variety of alerts. When all three are submerged everything is ok. When the two longer traces are still under water but the third is not an LED will blink to let you know it’s time. If you don’t pay attention and there’s no water left, a piezo buzzer makes noise until you add water (or the coin cell runs out of juice).

This project centers around an ATtiny85 that [Eric] programmed using an Arduino, one of the methods we covered in our AVR Programming Tutorial. But if this simple circuit isn’t high-tech enough for you, we saw a similar method last year that will send an alert to your iPhone.

Knitting Machine Hack By Keypad Emulation

December 6, 2010 by Mike Szczys 3 Comments

[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.

They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.

Star Trek Inspired Pocket Doors

December 6, 2010 by Mike Szczys 60 Comments

Do you have enough confidence in your hacking abilities to build a project into the walls of your home? [Marc] used his skills to build an air-powered sliding door for his bedroom. It is similar to the sliding door you’d find on the Enterprise, two sections that slide nicely into the wall to let you pass. Although the picture above shows the internals, he followed through and ended up with a fully finished room that looks fantastic. A compressor in the attic provides the pressure necessary to move the door sections. It is automated, but uses a button press or keypad combination to run instead of detecting motion. Of course, since he’s using a PIC microcontroller to drive the system there’s always room for future changes. Check out how great the finished look is in the video after the break.

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