Simple toy created by a combination of modern integrated circuits. from site
Through 12 LEDs arranged in a circle indicates the direction of the tilt angle and in any light and LED always placed high above the ground.
The following figure shows the wiring diagram Gravitron.
The basis Gravitron is an integrated accelerometer ADXL322 Analog Device companies using technology MEMS . Thus, on-chip integrated micro mechanical elements based on silicon and sensed through changes in capacity between itself and the basic element of a silicon plate. The output of the ADXL322 circuit are then two analog signals (Xout, Yout) representing the size of the absolute acceleration range of ± 2g.
They are then scanned ATmega168 microprocessor, which after appropriate evaluation of LED lights.
Fig. 2: Photographs mounted boards Gravitron
Theme PCB is not available, but as a two-layer board with vias would be its domestic production as well very difficult. However, device contains only a few parts, it is not a big problem for those interested in design your board exactly to your liking.
The control program for the microprocessor is available for download at the end of the article, and is intended for the GCC compiler. The following picture settings fuse programming circuit.
Although this is a very simple and easily realizable involvement, he can take with him certainly a lot of fun.