Kindle 2 teardown


The people at iFixit have shown that they’re still on top of their game by tearing down the new Kindle 2 eBook reader. The main processor is a 532MHz ARM-11 from Freescale. Interestly, there isn’t any significant circuitry behind the large keyboard; it seems its existence is just to hide the battery.

Related: previous teardowns on Hack a Day

[via Make]

Bristle bot controversy


When the Bristlebots were released back in 2007 by Evil Mad Scientist Laboratories, we all thought they were pretty cool. Apparently someone at Klutz did too. They have released a book, with the title “Invasion of the BristleBots”. The bots seem to be identical and the name is identical. There is no mention of Evil Mad Scientist Laboratories anywhere in it. [Phillip Torrone] has attempted to contact Klutz and the book publisher Scholastic directly to find out more information.

[Windell] and [Lenore] from EMSL had this to say:

“This is the first that I’ve heard of it. Frankly, I am a bit offended. Klutz makes some nice things, and I’m surprised that they wouldn’t have contacted us, asked permission, or at least given us credit. (Locomotion by ratcheting bristles isn’t remotely new — it occurs in nature — but the name ‘Bristlebot’ is surely ours, and I don’t know of any prior implementation with a toothbrush.)”

You probably know EMSL from their other projects such as the Peggy and Meggy jr. How would you feel if a project you did was published without credit? Would you care or not?

Wattcher, twittering Kill A Watt plans posted


You probably saw [Phillip Torrone] and [Limor Fried]‘s twittering Kill A Watt earlier this week. It was an entry in the Core77/Greener Gadgets Design Competition. We saw a little bit about how it was assembled, but now they’ve posted a full guide to assembling the hardware. Each Kill A Watt gets an XBee radio that transmits back to a receiver that logs the power usage. The difficult part when putting this design together was the XBee required 50mA when transmitting. This is well above the Kill A Watt’s internal power supply. They remedied this by adding a 10,000uF supercap to act as a rechargeable battery. The daily twittering is just a side-effect of the project. The Kill A Watts transmit every 2 seconds, so you’ll get a very accurate report of your power usage. This is a great project for renters who can’t permanently modify their power infrastructure. Each Kill A Watt can support quite a few appliances since they’re rated for 15A, ~1800W.

Tiny projector teardown


The team from Tech-On has taken the time to teardown two interesting microprojectors. The first model they tackled was the Optoma PK101. It’s based around a digital micromirror device (DMD) like those used in DLP. Separate high intensity red, green, and blue LEDs provide the light source. A fly-eye style lens reduces variations between images. They noted that both the LEDs and processors were tied directly to the chassis to dissipate heat.

The next projector was the 3M Co MPro110. It uses Liquid Crystal on Silicon (LCoS) technology. The light source is a single bright white LED. The projector seems to have more provisions for getting rid of heat than the previous one. The most interesting part was the resin polarizing beam splitter. It not only reflected specific polarizations, but also adjust the aspect ratio.

[via Make]

Make: television premiering today


Make’s television series will be premiering on public television across the US over the next couple days. If it’s not showing in your area, you aren’t out of luck. All of the segments from the first episode have already been published online at

Make: The Resistor

Embedded above is a short segment produced by Make about one of our most fundamental circuit components: the resistor. Although brief at just five minutes, it covers resistor basics and the historical development of Ohm’s law.

Arduino buyers guide and the Seeeduino


Make has assembled a buyers guide for the many different types of Arduino devices. The Arduino is an open hardware platform designed to make prototyping easily accessible. The design allows for other people to modify, expand, and improve on the base, and many people have started producing their own versions. The guide features a lot of the hardware we’ve covered in the past like the LilyPad, Arduino Pro, Sanguino, Duemilanove, Ethernet Shield, and Freeduino.

Out of the pack, the Seeeduino (pictured above) definitely caught our eye. It’s a low profile SMD design much like the Arduino Pro. They’ve taken advantage of the space saved by the SMD ATmega168 by adding more useful headers. In addition to the ICSP, you get the pins in UART order and an I2C header. Vcc is switch selectable for 3.3 or 5volts. The reset switch has been moved to the edge plus two additional ADC pins. Our favorite feature is the new spacing on the digital pins. Arduino digital pin headers have an inexplicable 160mil gap between the banks. The Seeeduino has the standard row for shield compatibility, but has an additional row spaced at standard 100mil spacing for use with protoboard. At $23.99, it’s competitively priced too.