Arduino Based Hourglass

This is a project that is functional and working so that anybody can make a real one. I had made the same circuit using attiny2313.

https://www.instructables.com/Attiny2313-Based-Electronic-Hourglass/

This was a little complex circuit to teach younger kids, considering the programming of the attiny chip and soldering all the LEDs and connecting them. So I made another one using arduino it will be easier for kids of grade 3 and above. Yes, I teach as a hobby.

Supplies

Nothing more than your hands, a computer and an internet connection.

Step 1: Truth Table

The truth table for the circuit can be seen in the adjoining figure. I have planned to connect the LED's in a way so that single pin can be used for the top and bottom triangle. You can understand the circuit in the next step.

Step 2: Circuit

Circuit is simple single pin is used to control 2 different LED's. Make sure the VCC is always connected to 3.3V. Connecting it to 5V makes both the LED's to light up and defeat the circuit's purpose.

Basic step: When pin is high one LED glows and when pin is low other LED glows.

Step 3:

Using the Above 2 steps start connecting the LEDs to the arduino.

For programming no complexity in loop function are used. Only straight program with delays are used.

Basic step: When pin is high one LED glows and when pin is low other LED glows.

Finally it is done. All working. Check the video for the functionality.