The Concept

I sometimes have trouble waking up in the morning, so I wanted to make a challenge for myself whenever I try to turn off my alarm clock. I already made a memory game, and I made a simple design for outputting to a 7-segment LED display, so I decided I wanted to integrate those designs into an alarm clock.

The Design

The box

I found an inexpensive aluminum project box online and decided to use it as the body for the alarm clock. I found some buttons with built-in LEDs for the memory game portion, and I decided to strategically drill holes in the front of the box to allow the time display to shine through. Like I mention in the demo video, I didn’t do a great job of this.

The Circuit Board

The main electrical components I have on the PCB are:

ATMega328 – system logic and I/O
DS1307 – Real Time Clock
3V coin cell for real time clock
LED Display
MAX7219 for LCD screen
Buzzer for alarm
Resistors, capacitors, and crystal oscillators

In order to fit everything into the small project box, I went with a stacking PCB design with two 2-layer boards.

: The first layer

: Second layer added

: Boards fitting into the case

The buttons and lights are connected by wires to the circuit board where they are directly soldered on. In future, I would like to modify this to a plug-in connection to make it easier to take the lid off for battery replacement.

Features