Microcontroller clock kit. The picture shows the 8031/8051 dice clock, made with the 8031 microcontroller, but aside from the fact that this uses one PIC16C57 and has 15 independently settable alarms instead of just 3 (and so there are 4 LEDs for RS3 through RS0, not just RS1 and RS0), this clock behaves in the exact same way. Contents are 49 LEDs, one programmed microcontroller, one 4-MHz crystal, 18 resistors, 2 capacitors for use with the crystal, an electrolytic capacitor, a 5-volt voltage regulator, 2 PNP transistors, 2 diodes, one miniature speaker, 2 pushbutton switches and a copy of the wiring diagram, which is also here:
A demonstration of this clock can be seen here (make sure to RIGHT CLICK on this link and tell it to save rather than left click to just open, because otherwise sneaky old mediafire will probably just redirect you to an ad):
Please feel free to check out our other electronic items at medexamtools.com/diodes.htm. These can be added into your order for combined shipping as well (the shopping cart system will do it automatically).