This project is a compact, battery-powered environmental monitoring device built around the ESP32. It is designed to measure temperature, humidity, and atmospheric pressure, and transmit data wirelessly over Wi-Fi.
The system integrates power management, battery charging, sensing, and communication into a single PCB, making it suitable for IoT applications and embedded product prototyping.
- ESP32-based Wi-Fi connectivity
- Environmental sensing (temperature, humidity, pressure)
- Battery-powered operation (Li-Po)
- USB-C power input and charging
- Integrated battery protection
- Low-power design (deep sleep capable)
- UART interface for programming and debugging
The system is composed of the following main subsystems:
- USB-C 5V input
- Li-Po battery charging IC
- Battery protection circuit
- 3.3V regulation stage
- Bulk and decoupling capacitors
- ESP32-WROOM-32 module
- Boot configuration and reset circuitry
- UART programming interface
- BME280 environmental sensor (I2C interface)
- Pull-up resistors for I2C communication
USB-C → Charger → Battery → Regulator → ESP32 → Sensor (I2C)
- Modular schematic organization (power / MCU / sensor)
- Proper decoupling and power distribution
- ESP32 antenna keep-out respected
- I2C bus design with pull-up resistors
- Battery protection and safe charging design
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ESP32 Module Selection Used a pre-certified ESP32 module to simplify RF design and ensure reliable Wi-Fi performance.
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Battery-Powered Architecture Designed around a single-cell Li-Po battery for portability and real-world IoT use cases.
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Power Regulation Strategy Implemented a regulated 3.3V rail to ensure stable operation during ESP32 current spikes.
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USB-C Power-Only Configuration USB-C connector used strictly for power input, avoiding unnecessary USB data complexity.
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I2C Sensor Interface Selected a digital sensor with I2C to minimize pin usage and simplify routing.
- 2-layer PCB
- Ground plane for signal integrity
- Compact component placement
- Standard SMD components (0603 passives)
- Connector placement optimized for usability
- Schematic files
- PCB layout files
- Gerbers
- Drill files
- Bill of Materials (BOM)
- Pick-and-place files
- Block diagram
- Rendered board images
- IoT environmental monitoring
- Smart home systems
- Remote sensing nodes
- Battery-powered embedded systems
- Power path optimization (load sharing / advanced charger IC)
- Lower power consumption tuning
- OTA firmware update support
- Enclosure design integration
- Additional sensor support
Hardware design and layout by Abdelwahed Eloued
This project is open-source and available under the MIT License.