A fun, simple LED clock, that will give you the time to the nearest half hour using single-color LEDs. Parts needed are as follows:
- Arduino Nano
- 400 tie-point Breadboard
- Ribbon Cable
- DS1307 RTC IC
- 32.768 kHz Crystal
- (12) 10mm LEDs
- (12) 180 Ohm resistors
- (2) 10k Ohm resistors
- 0.1″ spaced, 12 wire ribbon cable, 7″ long
- Jumper wires
- 18″ x 6″ 1/8″ acrylic
The tools needed for this job are:
- Laser Cutter
- Soldering iron, flux, solder
- Wire cutter
- Wire stripper
- Needle-nose pliers
- Vice (optional)
- Hot glue gun
- Arduino IDE installed on a computer
Step 1: Laser-cut clock casing
The first thing that needs to be done for this LED clock is to design the clock case! This gives the layout of your LEDs as well as a good housing to use to help keep the assembly very neat and simple. I attached my illustrator file that can be used on a laser cutter with 1/8″ acrylic and is designed to snap together.

Step 2: Place LEDs in Holes
The easiest way I have found to assemble this clock is as follows:
- Clamp the clock face in a vice and angle it so the engraved side faces downward
- Drop the 10 mm LEDs in the back of the clock in each of the 12 holes
Read more: Arduino-powered LED Clock