- Electricity: charge, current, voltage, resistanceThe four quantities behind every circuit, explained with a water hose, and your first LED that you predict before you build.
- Series, parallel and the voltage dividerWhere the current goes when there is one path or two, how a potentiometer's three pins work, and why the middle position measures less than you expect.
- Measuring with a multimeter: volts, amps, ohms and the beepThe one tool that shows you what is really happening in a circuit: how to measure voltage, current and resistance, find broken wires with the beep, and never blow the fuse.
- Capacitors: storing charge, RC timing and clean powerWhat a capacitor does, how to read its markings, why it charges along a curve, the RC time constant you can measure with a stopwatch, and the small capacitors that keep a robot from resetting.
- Current, magnetism and the DC motorWhy two wires with current pull or push each other, how that turns into a spinning motor, and why a motor needs a driver instead of a pin.
- The microcontroller and your first MicroPython programWhat a microcontroller is, the five kinds of pins, how to put MicroPython on an ESP32, and a blinking LED you write yourself.
- PWM: half a volt from a pin that only knows on and offThe bathtub puzzle, frequency and duty, how to turn a duty number into an average voltage, and a dimmer you program yourself.
- Diodes and transistors: switching big currents with a small pinThe diode as a one-way valve, the flyback diode that protects your circuit from a motor, and transistors that let a 3.3 V pin switch a motor or an LED strip, with PWM speed control in MicroPython.
- Sensors: buttons, knobs, light and measuring distance with soundDigital inputs, pull-up resistors and bouncing buttons, reading a knob and a light sensor with the ADC, the ultrasonic sensor that every small robot uses, and a first look at sensors that talk over I2C.
- Batteries, power supplies and safetyHow long a battery lasts, series and parallel cells, the rules for lithium cells, fuses, and why a buck converter beats a regulator that just burns the extra voltage.
- Reading schematics and datasheetsThe map of every circuit: symbols, dots, ground and net labels, part names like R1 and 4k7, then how to find the few numbers that matter in a datasheet. Ends with a complete robot power and motor circuit you can read on your own.