Stephen Musangi

PCB Design • Embedded Systems • IoT Hardware

Hello — I'm Stephen

Creating hardware that thinks — embedded systems & PCB design done right.

I design reliable microcontroller-based systems, structured PCB architectures, and integrated IoT platforms. My work spans driver-level firmware, high-speed digital interfaces, and complete hardware products — with a strong focus on stability, efficiency, and real-world deployability.

200+ Circuits & PCBs
7 Products
34k Hours
View projects
LTE Tracker PCB

LTE GPS Tracker with dual Power Modes

LTE Cat M1 / NB-IoT GPS tracker designed for asset monitoring, featuring efficient power management (dual supply), GNSS accuracy, and cloud connectivity.

LTE GPS Cloud IoT
Energy Controller PCB

Multi Channel Energy and IO control with WiFi and LTE

General purpose energy controller for managing multiple power sources (generator and mains) and loads with WiFi and LTE connectivity.

Energy Power Management Controller WiFi LTE
Inertia-Based LED Controller PCB

Inertia-Based LED Controller

An LED strip controller that uses inertial measurement unit (IMU) data to create dynamic lighting effects based on motion and orientation.

IMU LED Controller Inertia Lighting Effects
Cable Orientation Tester PCB

Cable Orientation and Connection Tester

A PCB that tests and verifies correct cable connections and orientations for various types of cables to ensure proper functionality and prevent damage.

Cable Tester
MIDI Controlled Steam Powered Calliope PCB

MIDI Controlled Steam Powered Calliope

A MIDI controller for musical solenoid valves pushing steam through whistles to create music with 12V power supply and ESP32 microcontroller.

MIDI Calliope ESP32 Solenoid Valves
STM32 PoE UWB Board PCB

PoE-Powered STM32 Board with DWM3000 UWB Module and USB Isolation

PoE powered STM32 microcontroller board integrated with DWM3000 UWB module for precise indoor positioning, featuring USB isolation for enhanced signal integrity.

PoE STM32 DWM3000 UWB
ESP32 HID Device PCB

ESP32 HID Device

A Human Interface Device (HID) based on the ESP32 microcontroller, designed for custom input/output applications and peripherals.

ESP32 HID USB LiPo
ESP32 S3-Based Control Board PCB

ESP32 S3-Based Control Board

A control board based on the ESP32 S3 microcontroller, designed for embedded applications requiring WiFi, Bluetooth, real-time clock and Data logging capabilities.

ESP32 S3 Control Board
Compute Module 4/5 Carrier Board PCB

Compute Module 4/5 Carrier Board

Compute Module 4 Carrier Board for servo control and sensor interfacing, camera support and Google Coral integration.

CM4 CM5 Carrier Board
LED Controller PCB

LED Controller

LED controller with USB C Power Delivery Input, MCU control, Timer circuit and vibration sensor integration.

LED Controller USB C Power Delivery Timer Vibration Sensor
E-Bike Controller PCB

E-Bike Controller

An E-Bike controller PCB designed to manage motor control, battery management, Lights switching, and user interface for electric bicycles.

E-Bike Motor Control User Interface
ESP32 Camera and Data Logger Board PCB

ESP32 Camera and Data Logger Board

Data logger and camera module based on the ESP32 microcontroller, designed for capturing images and logging data for various applications.

Data Logger Camera Module ESP32
Solenoid Locks Controller PCB

Solenoid Locks Controller with WiFi and BLE (ESP32)

Controller for solenoid locks with WiFi and Bluetooth Low Energy (BLE) connectivity, based on the ESP32 microcontroller.

Solenoid Locks ESP32 WiFi BLE
Yaw, Pitch, Roll Sensor Module PCB

Yaw, Pitch, Roll Sensor Module (9-Axis IMU)

A sensor module that measures yaw, pitch, and roll using a 9-axis inertial measurement unit (IMU) for applications in robotics, drones, and motion tracking.

Yaw Pitch Roll 9-Axis IMU
Access Control PCB

Access Control with Relay control, External LTE, NFC and QR code scanner, Ethernet and RTC

Ethernet based access control system with relay control, external LTE, NFC and QR code scanner, and RTC for time-based access management.

Ethernet Access Control Relay Control LTE NFC QR Code
Stepper Motor LED Controller PCB

Stepper Motor LED Controller

High Current Stepper Motor LED Controller

High Current Stepper Motor LED Controller

Client PCB Designs — Manufacturing & Test Validation

Freelance Hardware & Embedded Systems Work

Shown below are selected printed circuit boards designed for clients and later manufactured and tested by them. Images were provided by clients during validation and bring-up phases following design delivery.

Client PCB assembled for testing
Client PCB assembled for testing
Manufactured client PCB during validation
Client PCB under functional testing
Client PCB under functional testing
Client PCB under functional testing
Client PCB under functional testing

Client identities and proprietary details are omitted for confidentiality. All designs shown were completed and delivered for client-led testing. All PCB images shown are used with explicit permission from the respective clients for portfolio and professional showcase purposes.

Applied Research & Product Development — CDED

Product Engineer · Dedan Kimathi University of Technology

I was directly involved in the design, prototyping, and validation of the three embedded products shown below — including an air quality monitoring device, an attendance and clock-in system, and a smart card programming device — taking each from concept through functional hardware prototypes, firmware development, and system-level testing with emphasis on reliability, manufacturability, and real-world deployment.

CDED Air Quality Monitoring Device CDED Attendance and Clock-in System CDED Smart Card Programming Device

About Me

I’m an embedded systems and hardware engineer specializing in designing reliable, simulation-driven electronic systems. My expertise spans the entire hardware development pipeline, including:

  • Requirements-to-Hardware Translation: Turning functional requirements into validated circuit designs and embedded architectures.
  • Simulation-Driven Engineering: Using LTspice and analytical methods to verify behavior, optimize performance, and eliminate design risks early.
  • Circuit & PCB Development: Creating production-ready schematics and PCB layouts with focus on signal integrity, power delivery, EMI/EMC, thermal paths, and manufacturability.
  • Custom Development Boards: Designing test and evaluation boards to accelerate firmware development, sensor testing, driver tuning, and system validation.
  • IoT Hardware Architecture: Integrating sensors, wireless radios, power systems, and MCU-level control into complete, deployment-ready hardware platforms.
  • Low-Level Firmware Engineering: Implementing drivers, peripheral interfaces, and embedded control logic for ESP32, STM32, nRF, and Atmega platforms.
  • End-to-End Hardware Delivery: Documenting design decisions, generating BOMs, preparing manufacturing files, and supporting prototype-to-production transitions.