Learn electronics
Plain-language guides to microcontrollers, circuits, sensors and power. Written for people who want to build things, not pass an exam. No account, no paywall, and nothing here assumes you already know the jargon.
Foundations
Start here if electronics is new to you. No prior knowledge assumed.
What a microcontroller actually is
A whole computer on a single chip, small enough to lose in your palm — what's inside one, how its programs work, and why it's the right tool for things a laptop can't do.
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Electricity, explained with water
Voltage, current, resistance and Ohm's law, plus what resistors, capacitors, inductors and transistors actually do, all built on one picture: water moving through pipes.
ReadWorking with hardware
How the parts actually behave once you start wiring things together.
Powering your project
Why your circuit works on one USB port and misbehaves on another — and how to size a supply before you burn an afternoon debugging code that was never broken.
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Staying inside the limits
Getting a circuit to work is the easy part. The real engineering is making sure every part can take the voltage, current and heat it will see, and the datasheet is where you find out.
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Getting the voltage you need
Why one project needs several different voltages, why a resistor can't give you one, and how LDOs and buck converters turn the supply you have into the supply you need.
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Buttons, pull-ups and bounce
A button is the simplest input there is, and it still has three surprises waiting: pins that read garbage, presses that count five times, and code that counts a hundred thousand. Here's how to tame all three.
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PWM: faking analog with fast switching
A microcontroller pin can only be on or off, yet it can dim an LED, set a motor's speed and play a tune. The trick is switching very fast, and choosing how long to stay on.
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Driving motors
Why a microcontroller pin can't run a motor on its own, how a transistor and an H-bridge take over, and the start-up current that catches almost everyone out.
ReadBuilding something
Sensors, power and the practical business of finishing a project.
Addressable LEDs, explained
How a single data wire controls hundreds of LEDs, why a strip that works on your desk misbehaves at full length, and how to power, protect and debug them.
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Doing several things at once
Blink an LED, watch a button and read a sensor, all at the same time. Why delay() makes that impossible, and the simple clock-watching pattern that fixes it for good.
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I2C and the Qwiic connector
How a single pair of wires can carry a motion sensor, a barometer, a compass and whatever you plug in next, and how to find and fix the problems when two of them disagree.
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Motion, pressure and heading: the Vector S3's sensors
Your board can tell which way is down, how fast it's turning, how high it is and which way is north. Here's what each sensor really measures, where each one lies to you, and how to combine them.
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