The Count up Box

For Valentine’s day 2016, I decided to make a device to count up how much time has passed since my girlfriend and I first met.

What I came up with is a fairly simple design utilizing an Arduino nano, a real time clock, an LCD screen, and a rotary encoder.

As I have some decent experience with laser cutting from my Sleep Sensei project, I decided to have the project laser cut.

Demo Video

Photos

Technical Details

The knob on the top of the box is attached to a rotary encoder with a built-in momentary switch. I use this to change the unit display on screen and allow the user to adjust the date and time.

Getting the screen working was the largest challenge of this project. It is a 1602 16×2 HD44780 screen from aliexpress, and it uses an I2C converter to allow me to send it commands via an I2C interface, simplifying the wiring significantly. However, it was hard to find the correct arduino library to interface with it. After much searching and testing, the LiquidCrystal_I2C library was the one that worked for me. The documentation for this library isn’t the greatest, but the commands can be found in the LiquidCrystal_I2C.h file.

The whole project is powered directly from the Arduino nano. This allows for easy code swapping and prototyping since the power cable is also the communications cable, and it simplifies the design of the circuit board since I can use the nano’s on-board power supply.

The code, lasercutting files, board schematics, parts list, and more details can be found on my GitHub:

https://github.com/jerwil/Count_Up_Time

Circuit Board Design

The circuit board was designed in Fritzing, and the design files can be found on the GitHub page.