Electronics & Circuits

Electrical fundamentals, circuits, components, and power systems
Voltage Vera, your electronics guide

Your guide: Voltage Vera

“Before you blame the code, follow the current — most ‘bugs’ are a loose ground or a wrong resistor.”

Introduction to Electronics & Circuits

Electrical fundamentals, circuits, components, and power systems

About This Part

This is Part 2.1 of the IoT Class curriculum, which covers electronics & circuits topics as part of Module 2: Physical World.

If you are building IoT systems, this part explains how the physical device actually works. Sensors, LEDs, relays, motors, batteries, voltage dividers, transistor switches, ADCs, and PWM outputs all live here. Without this layer, code has nothing reliable to read from and nothing safe to control.

This section contains 19 chapters: this introduction page plus 18 teaching chapters organized into three learning blocks:

  • Electricity Basics: voltage, current, resistance, Ohm’s Law, common mistakes, and the first calculations you need for safe IoT circuits
  • Electronics Basics: components, semiconductors, diodes, and the transistor switching ideas behind real GPIO-to-load interfaces
  • Analog & Digital: binary representation, ADCs, sampling, PWM, and worked examples that connect physical signals to software behavior

Start Simple

Imagine a learner holding a sensor board, an LED, and a battery but not yet knowing why the parts behave. This module is the plain-language route from that object to the circuit rules behind it: make current safe, choose components deliberately, and turn physical signals into numbers the device can trust. Start with one visible effect, one measured voltage, one current path, and one reason the design will not damage the hardware.

Why Study This Part

Electronics is where IoT stops being only software and becomes a real device. This part explains why parts need protection, why microcontroller pins have limits, why batteries and resistors must be chosen carefully, and why a circuit that looks simple can still fail in practice.

If you are a beginner, the main goal is not to memorize formulas. It is to build enough physical intuition that you can look at a sensor, LED, relay, transistor, or analog input and explain what the circuit is trying to do.

What You Will Be Able To Do

  • Read beginner-level schematics with much less guesswork.
  • Choose safer resistor, diode, transistor, and power-interface arrangements for simple IoT projects.
  • Understand how analog sensor signals become digital data and how digital outputs become useful physical actions.
  • Debug common hardware problems with a clearer mental model instead of trial and error.

How to Study This Part

  • Go in order if you are new: the chapter sequence is designed to reduce overload.
  • Tie each chapter to a real object: think about a smart light, sensor node, relay board, fan controller, or battery-powered device as you read.
  • Use the interactive pieces actively: the simulators, quizzes, and worked examples are where the formulas become practical.
  • Pause between learning blocks: after electricity, electronics basics, and analog/digital topics, ask yourself what you can now explain or design that you could not before.