From Electronics Fundamentals to PCB Design in KiCad

This workshop connects the basic vocabulary of electronics with the practical workflow of designing a printed circuit board in KiCad. The goal is not only to recognize components or draw traces, but to understand how lab instruments, sensors, actuators, microcontrollers, datasheets, schematics, footprints, PCB layout, and fabrication decisions fit together.

The flow is:

• lab instruments and signal measurement;
• power, signals, sensors, and data acquisition;
• microcontrollers and embedded systems;
• actuators, motors, and motor drivers;
• electronics fundamentals;
• symbols, schematics, datasheets, and footprints;
• PCB layout and routing;
• KiCad workflow;
• fabrication outputs and final checks.

Sections

• Lab instruments and signal measurement
• Power, signals, sensors, and interfaces
• Microcontrollers and embedded systems
• Actuators, motors, and motor drivers
• Electronics fundamentals
• Symbols, schematics, datasheets, and footprints
• PCB design: from circuit to board
• KiCad workflow and the workshop PCB
• Fabrication and final checks
• Credits and image notes

1. Lab Instruments and Signal Measurement

Electronics work starts with measurement. Before choosing a component, writing firmware, or designing a PCB, we need to know what is actually happening in the circuit.

The basic questions are:

• What voltage is present?
• How much current is being drawn?
• Is the signal DC, AC, PWM, digital, analog, noisy, or distorted?
• Is the circuit behaving the same way under load as it does with no load?
• Is the problem in power delivery, signal timing, wiring, firmware, or the component itself?

The four basic bench instruments are:

• Multimeter: measures voltage, current, resistance, continuity, and sometimes capacitance or diode drop.
• DC power supply: provides controlled voltage and usually a current limit.
• Function generator: creates known test signals such as sine, square, triangle, and pulse waveforms.
• Oscilloscope: shows voltage versus time.

For a DC power supply, the important settings are:

• maximum voltage;
• maximum current;
• current limit;
• fixed or variable output;
• single-channel or multi-channel output;
• whether the channels are isolated or share a common ground.

Current limiting matters because a prototype can have a wiring mistake, solder bridge, reversed connector, or shorted component. A current limit will not make a bad circuit correct, but it can reduce the damage during first power-up.

2. Power, Signals, Sensors, and Interfaces

One of the most useful distinctions in electronics is power versus signal.

• Power lines deliver energy.
• Signal lines carry information.
• A power path is usually sized for voltage drop, heating, connector rating, and current.
• A signal path is usually judged by voltage level, timing, noise, impedance, and logic compatibility.
• A motor, heater, LED strip, or actuator may need substantial current.
• A microcontroller pin is usually a control or sensing node, not a power source.

This distinction is important in robotics because sensors, microcontrollers, motors, and drivers are often connected in the same system but do very different electrical jobs.

A sensor should be selected by more than its name. For every sensor, check:

• supply voltage;
• current requirement;
• output type;
• analog range or digital logic level;
• sampling rate;
• connector or pinout;
• communication interface;
• mounting method;
• accuracy and calibration requirements;
• environmental range;
• datasheet notes about pullups, filtering, startup delay, or warm-up time.

Common sensor output/interface types include:

• analog voltage;
• analog current;
• digital output;
• PWM;
• I²C;
• SPI;
• UART;
• CAN or other field buses in larger systems.

Sensor categories from a practical design point of view:

• Active sensors: require power and produce an electrical output.
• Passive sensors: change resistance, capacitance, inductance, or another property and need a readout circuit.
• Powered modules: include supporting electronics and often expose an easy interface.
• Unpowered sensing elements: need excitation, signal conditioning, or measurement circuitry.

3. Microcontrollers and Embedded Systems

A processor executes instructions. A microprocessor is mainly a CPU and generally needs external memory and peripherals. A microcontroller combines the CPU, memory, timers, communication hardware, and I/O on one chip.

Microcontrollers are common in mechatronics because they can:

• read sensors;
• process data;
• control actuators;
• run timing-critical logic;
• communicate with a computer, phone, or another board;
• implement state machines;
• enforce safety limits;
• log data or transmit telemetry.

Examples include:

• Arduino boards;
• ESP32 boards;
• STM32 boards;
• PIC microcontrollers;
• development boards built around application-specific MCUs.

Typical microcontroller interfaces include:

• GPIO: on/off digital input or output;
• ADC: reading analog voltages;
• PWM: motor speed, LED dimming, or servo-style control;
• UART: serial communication;
• I²C: short-distance bus for many sensors;
• SPI: faster board-level communication;
• USB/Wi-Fi/Bluetooth: computer or network communication, depending on the board.

The key limitation is current. A GPIO pin can provide a control signal, but it cannot power a motor. That is why a motor driver is needed between the microcontroller and the motor.

4. Actuators, Motors, and Motor Drivers

Actuators convert electrical energy into physical action. In robotics and mechatronics, common actuator types include:

• DC motor: continuous rotation, speed control;
• geared DC motor: lower speed, higher torque;
• servo motor: position-controlled motion;
• stepper motor: precise incremental motion;
• BLDC motor: efficient, high-speed operation;
• linear actuator: controlled extension/retraction;
• solenoid: short-stroke on/off motion.

A motor driver is used because:

• a microcontroller pin cannot supply motor current;
• motors generate electrical noise;
• inductive loads can create voltage spikes;
• direction control often requires an H-bridge or inverter stage;
• speed control usually requires PWM switching;
• braking and enable behavior need proper switching circuitry;
• driver selection depends on motor voltage and peak/continuous current.

When choosing a motor driver, check:

• motor type;
• supply voltage range;
• continuous current rating;
• peak current rating;
• stall current of the motor;
• control interface;
• package and solderability;
• thermal behavior;
• protection features;
• whether the driver needs external diodes, capacitors, sense resistors, or heat sinking.

Size the power supply, driver, trace width, connector, and wiring for the worst credible current, not only the no-load current.

5. Electronics Fundamentals

The basic electrical terms become the language of debugging:

• Voltage: electrical potential difference, often treated as the driving force.
• Current: flow of charge through a closed path.
• Load: the device consuming power.
• Impedance: opposition to current flow.
• Closed circuit: complete path, so current can flow.
• Open circuit: broken path, so current cannot flow.
• Short circuit: very low impedance path, often causing excessive current.

Electrical power is usually estimated using:

P = V I

Important current terms:

• rated current: current during normal operation;
• starting current: current during startup, often higher than running current;
• stall current: current when a motor is energized but cannot rotate;
• peak current: short-duration maximum current;
• continuous current: current that can be sustained thermally.

For motors, the answer to "does current depend on resistance or load?" is: it depends on the operating condition. A motor is not just a fixed resistor. Its current depends on supply voltage, winding resistance, back EMF, mechanical load, speed, and driver behavior.

Common components include:

• resistors;
• capacitors;
• inductors;
• diodes;
• LEDs;
• switches;
• relays;
• fuses;
• connectors;
• sensors;
• power modules;
• microcontrollers;
• op-amps;
• motor drivers;
• voltage regulators.

6. Symbols, Schematics, Datasheets, and Footprints

A schematic is the logical representation of the circuit. It shows what is connected to what; it does not show the final physical placement of parts on the PCB.

Important schematic concepts:

• power symbols;
• ground symbols;
• wires;
• junctions;
• nets;
• net labels;
• reference designators;
• component values;
• pin numbers;
• pin names;
• connectors;
• no-connect markers;
• hierarchical blocks for larger designs.

When you do not know how to build a circuit around an IC, start from the datasheet. This is one of the most important practical habits in PCB design.

The datasheet usually tells you:

• pinout;
• absolute maximum ratings;
• recommended operating conditions;
• electrical characteristics;
• typical application circuits;
• component value recommendations;
• layout notes;
• thermal limits;
• package dimensions;
• part-number variants.

For a first circuit, the safest workflow is:

• start with the component datasheet;
• follow the manufacturer's recommended circuit;
• use reference designs and application notes;
• copy proven circuits before modifying them;
• use a development board when unsure;
• test the circuit before designing the PCB;
• only then convert the circuit into a custom board.

Examples:

• LED blinker: NE555P timer;
• dual DC motor control: DRV8833PWR motor driver;
• analog temperature sensing: LM35DZ/NOPB sensor;
• step-down voltage conversion: LM2596 buck regulator.

LM2596 example: why this circuit is included

The LM2596 circuit is not just a random datasheet image. It shows the normal engineering path from a need to a circuit:

• Need: convert a 12 V input to an adjustable 5 V output.
• Selected IC: LM2596-ADJ buck regulator.
• Reason for a buck regulator: dropping 12 V to 5 V with a linear regulator can waste significant power as heat, especially when the load current is not tiny.
• Next step: open the LM2596 datasheet.
• Starting point: use the manufacturer's typical application circuit.
• Design task: choose the external inductor, diode, capacitors, and feedback resistors according to the datasheet guidance.
• PCB task: place the switching loop carefully, keep high-current paths short, and pay attention to ground return and thermal behavior.
• Validation task: test output voltage, ripple, load behavior, and heating before powering downstream electronics.

The distinction between symbol, footprint, and part number is also critical:

• the symbol describes the electrical function in the schematic;
• the footprint describes the physical pads and dimensions on the PCB;
• the part number identifies the exact manufacturer-specific component.

Choose components by:

• electrical ratings;
• package;
• pinout;
• availability;
• cost;
• assembly method;
• operating environment;
• whether hand soldering is realistic.

Mounting styles include:

• through-hole;
• surface-mount;
• panel-mount;
• bulkhead-mount;
• module/header-based mounting.

7. PCB Design: From Circuit to Board

A printed circuit board holds and connects components. Copper traces replace wires, pads provide soldering points, and layers carry power and signals.

A good PCB is not only "a schematic turned into copper." It is also:

• electrical design;
• mechanical design;
• thermal design;
• manufacturing preparation;
• assembly planning;
• documentation.

Before starting layout:

• define the circuit and its function;
• test or simulate the circuit if possible;
• determine power and current requirements;
• select connectors and their physical placement;
• choose exact component part numbers;
• verify packages, pinouts, and footprints;
• draw and check the schematic in KiCad;
• begin PCB layout only after these steps.

During copper routing:

• connect pads with copper traces;
• keep paths short and organized;
• size traces for current;
• maintain spacing and clearance;
• use vias to change layers;
• keep noisy/high-current paths away from sensitive signals;
• use ground and power zones where appropriate;
• run Design Rule Check.

Important PCB physical concepts:

• substrate/core;
• copper layers;
• traces;
• pads;
• vias and plated holes;
• solder mask;
• silkscreen;
• board outline / Edge.Cuts;
• copper zones / pours;
• thermal relief;
• mounting holes;
• connector orientation.

8. KiCad Workflow and the Workshop PCB

Electronic Design Automation software is used for schematic capture, simulation, PCB layout, and manufacturing files. Examples include:

• KiCad;
• Altium Designer;
• Cadence OrCAD / Allegro;
• Autodesk Fusion Electronics / EAGLE;
• EasyEDA;
• LTspice / PSpice.

KiCad is useful for this workshop because it is:

• free and open source;
• capable of complete schematic and PCB workflow;
• supported by large symbol and footprint libraries;
• able to show 3D PCB visualization;
• not restricted by small educational board-size limits;
• widely used in education, hobby work, and professional engineering.

Download KiCad from: https://www.kicad.org/download/

Basic KiCad project flow:

1. Open the KiCad Project Manager.
2. Create a new project.
3. Open the Schematic Editor.
4. Place symbols.
5. Wire the circuit.
6. Assign reference designators.
7. Add values and part information.
8. Assign footprints.
9. Run electrical checks.
10. Open PCB Editor.
11. Import/update PCB from schematic.
12. Place components.
13. Route traces and copper zones.
14. Run DRC.
15. Inspect the 3D view.
16. Export manufacturing files.

The workshop design is a robot-controller PCB. The intended board includes:

• microcontroller mounted on pin headers;
• 12 V power input through a screw terminal;
• two 3-pin sensor connectors: 5 V, GND, SIGNAL;
• motor-driver and DC motor connectors;
• status LED with a 330 ohm resistor;
• power and ground net labels;
• mounting holes and labeled connectors.

Component choices from the workshop:

• controller: Adafruit Feather HUZZAH32 ESP32;
• motor driver: DRV8212PDSGR, WSON-8;
• 2-pin connector: JST_PH_B2B;
• regulator: 1117-5.0;
• LED: LED_1206_3216Metric;
• resistors: R_1206_3216Metric;
• mounting holes: MountingHole_3.2mm_M3;
• board size: 50 mm × 30 mm.

Managing a PCB project requires keeping track of:

• reference designators: R1, C1, U1, J1, and so on;
• exact manufacturer part numbers;
• component values and ratings;
• voltage ratings;
• current ratings;
• package sizes;
• Bill of Materials;
• footprint and package verification;
• net names and connector labels;
• silkscreen labels such as PWR, IN, OUT, and GND;
• Gerber files;
• drill files;
• pick-and-place files;
• CAD output and project archive.

9. Fabrication and Final Checks

Fabrication starts after schematic checks, footprint assignment, placement, routing, and DRC.

Fabrication options include:

• in-house DIY methods;
• university or lab PCB milling, when available;
• commercial PCB fabrication;
• PCB assembly service when the board uses many SMD parts.

Typical fabrication workflow:

1. Export Gerber files.
2. Export drill files.
3. Upload files for an instant quote.
4. Review the manufacturer preview.
5. Select size, layer count, quantity, copper weight, surface finish, solder-mask color, and delivery speed.
6. For assembly, provide a BOM and pick-and-place files.
7. Run DRC again before ordering.
8. Inspect the manufacturer preview before paying.

Examples of fabrication services mentioned in the workshop:

• DigiKey DKRed / PCB Builder: made in USA;
• JLCPCB / PCBWay: low-cost overseas prototypes;
• KiCad Plugin and Content Manager: PCBWay Fabrication Toolkit.

The cost depends on:

• board size;
• layer count;
• quantity;
• copper weight;
• finish;
• assembly requirements;
• shipping speed;
• whether special options such as castellated holes, impedance control, or panelization are required.

Before powering the fabricated board:

• inspect solder joints;
• check connector polarity;
• check for visible shorts;
• verify supply rails with a multimeter;
• use current limiting on first power-up;
• test the regulator output before attaching expensive modules;
• confirm microcontroller orientation;
• verify motor-driver pins before connecting a motor;
• test with the robot unloaded before full operation.

Credits and Image Notes

Workshop content and PCB CAD renders are credited to Umar Masood and the Society of Mechanical Engineering Graduate Students (SoMEGS), University of Houston, for the July 2, 2026 electronics and KiCad workshop.

Image/source notes:

• Product, instrument, component, and module reference visuals are used for educational explanation and remain credited to their respective manufacturers, vendors, or original rights holders.
• The LM2596 typical-application circuit image is credited to Texas Instruments documentation.
• KiCad names and marks belong to the KiCad project and their respective owners.
• The workshop PCB render images are from the workshop design material.