Bay Area Maker Faire: Hackaday has arrived!

It’s a madhouse already at the 2011 Bay Area Maker Faire. Though the show doesn’t officially start until tomorrow, Friday is “Education Day”, a special preview for local schools. As makers scramble to set up their displays, a thousand impressionable young minds seek the most cacophonous mixture of taiko drumming, ArcAttack’s musical Tesla coils, and the beeping and booping of the R2-D2 Builder’s Club.

Maker Faire is returning for its sixth year at the San Mateo Event Center, and is shaping up to be bigger and zanier than ever. We’ll do our best to provide some live updates through the weekend. As always, check out the official site for pointers on hours, admission, parking and especially public transit options.

(Photo: Colossus, the death-defying centerpiece of the Midway area of the Faire.)

Send email, receive surveilance picture

This deathstar like ball is actually an autonomous surveillance camera. [Basil] wrote in to tell us about it. The body is custom designed for the project, then 3d printed.  It can be dropped anywhere, as it is battery powered for up to a month,  and communicates via cellar networks.  It checks an email folder once an hour and responds to any requests with a snapshot of what is going on. In the video, which you can see after the break, he gets an immediate response.  You can download the sourcecode as well as the files for the enclosure here.

If you wanted to reduce costs, that case could be done away with, but we suspect it helps with some moderate weather conditioning. We would also love to see a version that rotated around that equator on command for better pictures. Great job [Basil].

Continue reading “Send email, receive surveilance picture”

Introduction to the H-bridge motor controller

[Chris] sent us this fantastic tutorial, introducing beginners to H-bridge motor drivers. While many of you will consider this stuff basic, those who are trying to expand from building only things the arduino board can handle to bigger more expansive (and powerful) projects will find this quite helpful.  [Chris’s] tutorial is very in depth, not only going through the construction of the basic circuit but also showing you how to make your own PCB.  Pop on over there and learn some theory and some practice. Then you can build that battle bot you’ve always been dreaming of!

Using an AVR as an RFID tag

A few years ago, [Beth] came up with the idea of using an AVR as an RFID tag. She’s gotten sidetracked with a few other projects in the meantime but her idea has surfaced again, this time as a duct tape RFID tag. The build is just four components: 0.1 µF and 1 nF capacitors, an ATtiny85 microcontroller, and 100 turns of 40 AWG magnet wire, all soldered together and placed on a duct tape substrate.

Like most RFID tags, the power is drawn from the reader through the coil, but even in low power versions the ATtiny is only rated down to 1.8 Volts. Since the microcontroller is only getting about 1 Volt from the coil, the clock oscillator of the ATtiny won’t work. This isn’t a problem in this build, because the coil is connected to the the clock input – the 125 kHz coming off the reader provides the clock. Very clever.

Of course, the microcontroller is going to need some firmware to send some bits to the reader, so she used the AVRFID firmware (check out the comments in the source for a great walkthrough) to transmit under the HID protocol, itself a derivative of [Beth]’s earlier work with the EM4102 protocol.

Not only are we impressed with this hack, we’re amazed [Beth] is still perfecting her work more than two years after her first post on the subject. That’s dedication and unbridled cleverness.

Via adafruit

DIY Spectrophotometer

[Charlie] has been making a DIY Spectrophotometer, and while it is a “shambling mess of information-age technology!” it is still much better than ours. Focused around an arduino, bits of lego, and a flashlight, this creative device rotates a diffraction grating (flake of compact disc) aimed at a photo resistor. As the light spectrum is passed over the sample, the photo resistor measures how much light is reflected and that data is passed back to a pc.

As nothing is as ever easy as it should be, a big problem popped up with using a servo. It was way too course, meaning the entire spectrum would be jumped over in 6 steps. A quick robbery of a gear assembly from a floppy disk drive and the motor movement was smoothed out. A little too well because 120 degrees of the servo is not quite enough to cover the entire spectrum. Oh well there is always room for improvement.