LED_round_watch

This is a watch featuring 72 LEDs and an Arduino ATmega328 SMD Chip. For time keeping I used a tiny DS3231 RTC. This is a very accurate SMD RTC from Maxim. Among 72 LEDs, I used 12 Blue LEDs for displaying the hours and the other 60 for displaying the minutes and seconds.

Following is the screenshot of the top 3D view of the watch:

Bottom view:

The diameter of the watch face is 40mm. Designing the watch casing from scratch is tough and time consuming. It is possible to design a watch case using 3D printer but it will not be so cool like a commercial watch case and will not be a sustainable design. So, I decided to use a commercial watch case and I bought one 40mm Stainless Steel Watch Case from my local watch shop, almost similar to the product from Aliexpress. See the following image.

Then I designed the PCB of the watch according to the size of the watch case and got it assembled from the JLCPCB. The actual PCB looks like the following:

This is the top side of the PCB watch. Only the ATMega328P microcontroller, 8 resistors and the LEDs are placed on the top side. All other components are placed on the bottom side for aesthetic purposes.

On the bottom side of the PCB, a button is placed for time adjustment. The RTC is also placed on the bottom side with some resistors and capacitors.

I kept 6 open pads on the bottom of the PCB for programming purposes. You can directly upload a program to the watch using a 6-pin 2.54mm Pogo Pin Probe Clip or directly solder wires to the pads.