XY axes

Making an XY axis bot requires two stepper motors, and then either 2 belts or 2 rods.  Been used many times before in CNC machines and 3-D printers:
including
Makerbot
RepRap

Nice tutorial on constructing Y-axis and also idler pulley assembly from Makerbot

Stepper motors

Parallax #27964

Unipolar, 12VDC, 7.5o step angle.  Wiring is
1. Orange
2. Yellow
3. Black
4.Brown
COM Red


Using the adafruit stepper motor shield, with a bipolar stepper from an HP scanner, there was a bad smell, little crack, and I think I just fried half of the shield.  Well only the first blown chip so far, so not bad.

Motor mounts

Servo city has somegreat motor mounts

Controlling multiple RGB LEDs

The TLC 5940 - PWM driver chip can drive 16 channels from a single serial port. Sparkfun sells them.

Also Sparkfun has a great 3 RGB breakout board for making a great light for $9

Beautiful mathematical sand sculptures

From Bruce Shapiro, the inventor of the egg-bot, some beautiful sand sculptures that plot mathematical patterns

Tom Igoe from ITP and the Arduino team talks about the Arduino Uno

Video with Tom Igoe talking about the new arduino uno

tom_igoe_from_itp_and_the_arduino_t.html

Easy SMS messaging from arduino

from Make Club

Cheap and easy SMS via GSM for your MCU

http://hackaday.com/2010/10/18/cheap-and-easy-sms-via-gsm-for-your-mcu/

Non acronym version of the title: send and receive text messages via cell phone communication towers using an Arduino or other microcontroller. “We’ve been doing that for years!” you cry, well yes, technically. But [Fincham] lays it outs simply; commercial offerings are expensive and finding a cell phone that uses RS232 now a days is getting difficult, so a new way of doing the same old is necessary. The good news is USB GSM modems are readily available, cheap, and only require a few interface pins to get them talking with an Arduino. In fact, the image above is all you need.