Mesh_Handheld

1. Introduction

Mesh Handheld is a portable ESP32-based embedded system designed for decentralized communication and environmental sensing. The device integrates wireless networking, multiple onboard sensors, and a battery-powered system into a compact handheld form factor.

The goal of this project is to create a self-contained, modular platform for experimenting with mesh networking, embedded systems, and sensor integration.

2. Design Overview

The system is centered around an ESP32 microcontroller, selected for its integrated WiFi capabilities and support for mesh networking protocols. The design combines multiple subsystems into a single compact PCB:

Power management using the IP5306 charging and boost IC

Battery-powered operation with USB charging

Multiple onboard sensors (environmental and biometric)

Status LEDs for system feedback and debugging

Expandability through available GPIO

The device is intended to operate as a standalone node in a mesh network, while also serving as a general-purpose embedded development platform.

3. System Architecture

The system is divided into several functional blocks:

Power System: Battery input, charging IC, voltage regulation

Microcontroller: ESP32 handling communication and control

Sensors: Connected via I2C and other interfaces

User Interface: LEDs and potential input controls

These subsystems are carefully integrated to minimize interference and ensure reliable operation in a compact layout.

4. PCB Design Considerations

The PCB is being designed with focus on signal integrity, power stability, and compact layout:

Use of a 4-layer stackup (SIG-GND-PWR-SIG)

Continuous ground plane for low impedance return paths

Dedicated power distribution layer for stable voltage delivery

Careful placement of decoupling capacitors near ICs

Separation of noisy and sensitive signals where possible

Special attention is given to the ESP32 RF section to ensure proper antenna performance and minimal interference.

5. Current Progress

The schematic design has been completed, and PCB layout is currently in progress. Initial component placement and routing have been started, with focus on power integrity and compact design.

6. Challenges

The main challenges in this project include:

Routing density due to compact handheld form factor

Power system stability in a battery-powered design

Managing noise and interference between subsystems

Ensuring reliable RF performance for wireless communication

7. Why PCBWay Sponsorship Helps

This project requires multiple PCB iterations to validate and improve:

Power delivery and battery charging performance

Sensor integration and signal reliability

RF performance and antenna behavior

Access to high-quality PCB fabrication and fast turnaround times would allow rapid iteration and significantly improve the development process.

8. Additional Notes

This project is supported by a Hack Club grant and will be documented throughout development, including design decisions, challenges, and testing results.