Circuit Lake

There are many ways to create PCB at home. You can manually laying out the traces with trace transfers (not recommended), photo reproduction (specialized, and expensive), or the use of a laser printer using the toner transfer method. During my experience, creating PCB using the toner transfer method is easiest and low cost.
The procedure [...]

People still use 16-key keypad as input device for any embedded project. I could be used as code input device for opening a door or as a general input to any project that requiring the input like alarm circuits, games, puzzles, DTMF generators.
This project will show you how to interface a 16-key keypad to [...]

In this video tutorial, nerdkits show you how to use the timer interrupts on an ATMega168 chip to make a simple timer. It is possible to make your own reasonably accurate alarm clock, create systems to perform timed automated tasks, or create a multitude of other projects with real time clock in AVR.

If you want to learn Reverse Engineering you can use photoshop as aid tools. For example, This 12-keys keypad failed after years of daily use. No schematic or replacement parts from the original manufacturer. The only option was to replace it with an off-the-shelf telephone-style keyboard.Following the maze of each and every PCB track in [...]