Hardware

As can be seen form Figure 1 below and the schematic in the appendix, the system is very simple. All the parts chosen are cheaply and readily available off the shelf components. There is one spare I/O pin in the design that I would like to use in the future to set the alarm time increment amount.

Figure 1 Hardware overview.

Photos 3 and 4 below show the completed device that used an old pocket FM radio to house the timer and laser pointer. A CR2032 lithium cell has been used but found to be a little small for this project and so in future designs a more substantial power source would be used. Despite its second hand nature and rather untidy inside appearance the radio was an exceptionally good fit with the laser module slotting in nicely to shine out the hole originally intended for the headphone socket.

Photo 3Completed device using a salvaged pocket FM radio as a case. (click to zoom)		Photo 4 Completed device internals. Some modifications and super glue were required to effectively retro fit my design to the case. (click to zoom)