[adafruit] wrote in to let us know that the Tweet-a-Watt is now available in kit form. While the plans have been available for a while, a kit is a welcomed addition. The kit doesn’t include the Kill-a-Watt monitor, but rather the XBee adapters and parts necessary to make it talk to your Arduino or computer. The kit is $90, while the Kill-a-Watt can be found for roughly $20.
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.
ZigBee is a low-power communication system using digital radios. It’s intended to be easier to work with than Bluetooth. Adafruit recently added an adapter board for Digi’s XBee product line and has put together a great how-to to show the devices potential. Using two XBee radios and adapters you can wirelessly program an Arduino board. This would be great if your Arduino was installed in an inaccessible area or maybe it’s over 100feet away from where you’re working. The radios do serial communication just fine. What the how-to covers is getting the reset line working so the Arduino can restart automatically after you program it. Once the radio pair is configured properly, it will pass the RTS line state directly from one device to the other.
With the release of the Arduino Duemilanove, Adafruit is trying to shift out some old stock Arduino Diecimila by offering 10% off. [amk] noted that the new Duemilanove is not so much an upgrade as an Arduino with a new hat. The only changes were autoselecting power and a cutable reset line. The best part about the Adafruit sale is they’re offering Atmega328s preloaded with the Arduino bootloader as a $5 upgrade. The Atmega328 gives you twice the flash memory, twice the RAM, and twice the EEPROM than the original Atmega168.
[blip.tv ?posts_id=1345490&dest=-1]
Drawdio, designed by [Jay Silver], is a fun, simple toy that uses the conductive nature of pencil graphite to generate different sounds. When you use the Drawdio pencil to draw or write, you also simultaneously create music. The entire kit is available for sale at Adafruit Industries, or for the more adventurous, separate components and parts are listed. The circuit is fairly simple and we wonder what other devices people can come up with based on this theme.
Adafruit Industries sent us one of their SIM Reader kits a few weeks ago to test. Assembly was a breeze thanks to the through hole components and good documentation. We plugged it into our USB -> RS232 converter and tried out the provided pySimReader software. It worked fine, but our modern SIM card out of an N95 didn’t prove very interesting. It was too new to attempt cloning and being a smart phone it doesn’t rely on the SIM for storing anything unless you specifically tell it to. The story was the same for a SIM we pulled out of a Treo. We tried the device with [Dejan]’s SimScan and a copy of Woron Scan. Both worked without any issue. Conclusion: the device works great despite us lacking anything interesting to do with it.
ladyada continues to produce more and more interesting Arduino shields. This new GPS logger plugs into a standard Arduino board and has support for four different GPS receiver modules. On the backside of the board is an SD card slot where it stores the coordinates in a text file. The total runtime can vary from five hours to twenty depending on how you choose to power the device and how you use the device. How often you read the device and whether you maintain the GPS lock will affect the power consumption. Like all of ladyada’s projects, you’ll find a great construction guide and example code on her site.
