Every embedded device, from a smart thermostat to a factory sensor, is an electronic circuit first and a piece of software second. Before you write any firmware, it helps to understand what the hardware is doing, because most "software bugs" in this field turn out to be wiring, power, or signal problems.
You'll start with the three quantities behind everything, voltage, current, and resistance, and the way Ohm's law connects them. Then you'll meet the components that make up a board (resistors, capacitors, diodes, and transistors) and learn to read a schematic so you can follow how they are wired together.
Finally, you'll pick up your first piece of test equipment, the multimeter, and see how to measure voltage, current, resistance, and continuity. Once you've finished, move on to Microcontroller Architecture to see what sits at the center of the board.
Uses a water pump analogy to explain voltage, current, and resistance, then shows how Ohm's law ties the three together.
A beginner-friendly tour of the parts you will meet on every board: resistors, capacitors, diodes, and transistors, with what each one does and how to recognise it.
An introduction to circuit diagrams: how a schematic differs from a wiring diagram, what the common symbols mean, and how to follow the connections.
Setting up a digital multimeter and using it to measure voltage, current, resistance, and continuity, the first tool you reach for when a circuit misbehaves.