Digital Circuit Design 2�

Schematic Design

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Instructor: Soheyl F. Hagh

University of Vermont, Summer 2025

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Motivation

• Design your circuit
• Learn about design platforms
• Learn the wiring, Nets, Ports, etc.
• Learn about component footprints

Lecture (2/3) – Schematic Design

• Design the digital circuit on EasyEDA
• Convert the schematic to PCB

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Previously

• We assembled the circuit on a breadboard, but this has several drawbacks:��

• Unstable connections: Wires or parts can easily come loose.

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• Low current capacity: Not suitable for high-power circuits.

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• Signal interference: Stray capacitance affects sensitive signals.

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• Messy layout: Hard to track connections in complex circuits.

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Solution:

Design a schematic and convert it to Printed Circuit Board.

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Schematics introduction

• Why Use PCBs – Durable and compact, PCBs support components and provide reliable electrical connections.

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• Key PCB Factors – Include material, copper thickness, layers, trace width, spacing, and impedance control.

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• PCB Design Tools – Tools like EasyEDA, KiCAD, and Altium streamline schematic-to-PCB workflows.

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• From Breadboard to PCB – Transition improves reliability; starts with schematic design in EasyEDA.

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• Starting with EasyEDA – Create an account at easyeda.com using Google or email.

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• Creating a Project – After logging in, select “Design Online” → “Std Edition” to begin designing.

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Section 1 (a): EasyEDA

• Navigate to https://easyeda.com
• Click on the Login/Register button in the right corner of the screen.
• You may either use your Gmail and click the “Sign in with Google” button and follow the instructions, or use an Email address and a password to sign up.
• Enter your information, click “Send Code” to verify your email, and finally log in.

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Section 1 (b): A Blank Project

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Canvas and Library

Placing a resistor on Canvas

Library

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Section 2 (a): The schematic

Find and place the components below on your canvas, then use ‘W’ to start the wiring

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Section 2 (a): Finished schematic

This is the basic circuit required to program the microcontroller.

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Section 2 (b): LEDs and DHT22 Sensor

Use the Net Port option to connect your LEDs and peripherals.

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Section 2 (b): Ultrasonic sensor

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Section 2 (c): 3.3V regulator and OLED

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