General

XBee Broadcast Time as received by Luscious Electric Delight – click for movie (L.E.D. created by Leif Krinkle with Rob Faludi and Benedetta Piantella) The real-time clock which broadcasts time to the entire ITP floor via XBee ZigBee radio is now complete. Its time signal can be picked up by any project on the floor […]

Ariel’s Portrait Sai Sriskandarajah, Matt Chmiel, Teresa Porter and I created the Human Empowered, Pixel Optimized Camera Rendering Asynchronous Process for the Physical Computing without Computers course at ITP. This project recreates the digital camera rendering process, but instead of using microprocessors, human beings are enlisted to encode, digitize and render the image. Matt Encodes

New Micros makes an nifty yet expensive XBee Dongle carrier that plugs an XBee radio directly into your computer’s USB port. It’s also available bundled with an XBee Pro. The schematic indicates that the hardware handshaking pins are connected, so this dongle should work for firmware upgrades as well.

Setting your own unique PAN ID prevents your radios from conflicting with other people’s projects. Most importantly, it prevents other people from accidentally interfering with your projects. Everyone at ITP that is using ZigBee 802.15.4 radios should select one or more unique PAN IDs for themselves, and set all their radios to use those PAN

XBee radios can now record and output multiple channels of digital and analog data without using microcontrollers. The latest firmware (version 10A1) supports up to seven channels of analog input, nine channels of digital I/O and two channels of analog (pulse-width modulation) output. These will be great for creating small sensor modules or miniature output

The AVR ATMEGA8 chip that comes with the basic Arduino board has 8K of memory. This isn’t very much and it quickly fills up even with a small amount of code and variables. The Arduino system now supports the ATMEGA168 chip as well, which has 16K of memory–comparatively huge! However Arduino 0006 environment does not

Heather, Zach and myself created four logic gates out of Legos scrounged from various Lego Technics vehicle model kits. Here’s an AND gate made using strings: 00 position 01 position 10 position 11 position, output is activated MOVIE! Here’s an Inverter created with rods: 0 postion, 1 output 1 postion, 0 output MOVIE! We made

Heather, Zach and myself created a two-bit adder using laser-cut foam core board, wire and marbles. We initially tried a “boat” design similar to the one used in our one-bit adder. The boats didn’t quite come together properly, so we decided to try Zach’s secondary design that was cut at the same time. It worked

This moisture sensor circuit is based on a design by Forrest Mims, and adds a Shunt Ammeter so that the output is 0 to +5 Volts instead of amperes. We are using it for the ITPlants project, so that when soil moisture drops below a minimum, the plant can make a phone call for help.

Heather, Zach and myself created a one-bit mechanical adder (with a carry function) that runs on marbles. I found the basic design online and we modified it to our purposes. Zach and Heather used cardboard, foamcore and genius to prototype the flip-flop mechanism, then mounted each on a cardboard box, adding ramps and chutes to