ESP32 4-Layer PCB & Sensor Module

A custom 4-layer PCB integrating ESP32, sensor suite & analog front-end

📹 Project Demo

YouTube: Design & assemble the 4-layer ESP32 IoT PCB

🧩 Project Overview

This project presents the end-to-end design, layout, fabrication and testing of a custom 4-layer printed circuit board (PCB) built around the ESP32 microcontroller. The board integrates multiple sensors and analog front-end components to facilitate IoT, sensing and embedded systems prototypes.

Key integrated components

• ESP32 WiFi/Bluetooth microcontroller (as the main compute node)
• Amplified microphone input for audio sensing
• BME280 module (temperature, pressure, humidity)
• Photocell / photorésistance for light sensing
• 4-layer PCB stack-up with dedicated power and ground planes for improved signal integrity and noise performance

📐 Design Highlights

• Full schematic capture and layout in KiCad (or Altium Designer if you used it)
• 4-layer routing: inner power/ground planes, optimized trace widths, controlled-impedance/clearance where required
• Careful placement and routing of analog front-end (microphone + amplifier) with respect to power & ground to minimise noise
• Testing and validation of all Input/Output (E/S) signals: sensor data acquisition, digital communications (UART, I²C, SPI)
• Serial communication validation with ESP32 to ensure correct sensor data capture and transmission

🛠️ Tools & Technologies

• PCB design: KiCad (or Altium Designer)
• Microcontroller: ESP32 (firmware written in C/C++ using ESP-IDF or Arduino framework)
• Sensors: BME280, microphone + amplifier, photorésistance
• Protocols & interfaces: I²C, SPI, UART, WiFi/Bluetooth
• Production & testing: board fabrication, assembly, signal validation, functional testing

✅ What You’ll Find in This Repo

• schematic/ – Folder containing the PCB schematic files
• layout/ – Folder for PCB layout/copper layer files
• firmware/ – ESP32 code (data acquisition, sensor reading, serial output)
• docs/ – Design notes, BOM (bill of materials), stack-up description, test results
• images/ – Photos of assembled board, test setup, sensors, measurements

🚀 Use Cases & Applications

This board is ideal for:

• IoT sensor nodes (environmental monitoring, audio sensing)
• Prototyping connected devices with multiple sensing modalities
• Embedded systems coursework or rapid prototyping for research
• Integration in robotics, wearables, smart home systems

📚 Next Steps & Enhancements

Possible future enhancements include:

• Integration of LoRa or LTE-M/NB-IoT communication for long-range connectivity
• Addition of power-management (e.g., battery, solar) for off-grid sensing nodes
• Enclosure design and industrialisation for deployment
• Firmware enhancement: edge-processing, machine-learning inference on-board

📄 License

This project is released under the MIT License. Feel free to use, adapt or remix the design for your own work.

🙋‍♂️ About Me

Marwen Mekni — Electrical Engineering student (Embedded Systems & IoT), with strong experience in embedded software, hardware design and IoT system integration.
🔗 LinkedIn
📧 mekni0845@gmail.com