COVID-19 Hand-Washing Timer

This academic project was completed in December 2020 for my Digital Systems class (ELET 2303). This course taught me the application of digital electronics, combinational logic circuits, MSI, and memory devices.

We decided to focus on engineering solutions for the COVID-19 pandemic, hence the idea of a hand-washing timer. Since we aimed to have these devices in every public facility, we carefully factored component costs.

The device is triggered by a motion sensor and counts down for 20 seconds and indicates the time with an LED display.

Looking back at this project, I would have improved the up/down counters by adding buffers to better simulate the timer. However, this project was a fun group learning experience that solidified my the understanding of digital logic.

Tools and Technologies:

• - Digital Logic
• - Boolean Algebra
• - AC/DC Circuit Design
• - NI MultiSim 14
• - NI Ultiboard 14

74LS192 Pin-Out Diagram

74LS47 Pin-Out Diagram

Block Diagram

MultiSim Circuit Design

2D Ultiboard PCB Design

3D Ultiboard PCB Design

Bulk Purchase Cost Breakdown (Minimum 10 pcs.)