We recently built a LED spinning top with message display. Its an improved version of a similar top published by Elektor in their December 2008 issue. The Elektor top can be spun only in one direction. The synchronization required to print message on the LEDs arranged along the radius of the top is achieved by detecting the earth’s magnetic field.
Our top can spin in either direction and print a message accordingly. In our improved version of the spinning top, we used 2-channels of magnetic field detector circuit placed 90 degrees apart along the circumference of the circular PCB, to provide quadrature phase output that allows the top to detect the direction of spin and thus is able to adjust the LED pattern appropriately.
The top uses a Tiny44 microcontroller and is powered by 2×1.5V AAA size batteries with a MAX756 DC-DC converter to provide the +5V power supply to the circuit. The circular PCB was made on the Modela milling machine.
Here are some photos of the stationary top:
What are your recent projects? Have you made your own circuit board lately? How about working with the Atmel microprocessors? What do you like about making your own toys or modifying the ones created by other people? Add your comments to the conversation, and contribute your photos and video to the Make Flickr pool.