DIY ESP32 Board for Battery Powered IoT Applications

Custom ESP32 PCB for battery-powered IoT sensor nodes. Board features: TP4056 LiPo charging circuit with DW01A protection, 3.3V LDO regulator (AMS1117), battery voltage divider to GPIO34 ADC for SoC% calculation, onboard SSD1306 OLED header, I2C and SPI sensor headers, deep sleep current < 10uA, USB-C charging port, UART programming via CH340G. Schematic in EasyEDA, PCB manufactured via JLCPCB. Deep sleep wake sources: timer, external GPIO interrupt, touch pad. Code demonstrates: WiFi sensor reading, deep sleep 5 minutes, wake, read sensor, transmit, sleep. Average current 0.3mA giving 30+ days on 2000mAh LiPo. Perfect for remote weather stations, soil monitors, asset trackers.

Detailed Project Description

DIY ESP32 Board for Battery Powered IoT Applications focuses on a specific hardware interface or peripheral and shows exactly how to wire it, drive it from firmware and verify it is working.

How It Works
1. The peripheral is connected to the controller using the required bus (SPI/I2C/UART/I2S/CAN/RS-485/PWM/ADC).
2. The driver library is initialised and the peripheral configured.
3. Firmware exchanges data with the peripheral and processes it (measure, decode, render, play).
4. Results are verified on a display, serial monitor or the receiving device.

Key Components and Their Role
- ESP32: dual-core Wi-Fi + Bluetooth microcontroller that runs the firmware, reads the sensors and hosts the network connection.
- OLED display (SSD1306): 128x64 I2C display used to show live readings and status.
- Li-ion battery + charger (TP4056): portable power with charge management.

Implementation Steps
1. Collect the components and study each module's datasheet (pin-out, voltage, interface).
2. Wire the circuit on a breadboard following the pin mapping; power sensors from the correct rail (3.3 V / 5 V).
3. Install Arduino IDE, EasyEDA PCB Design, JLCPCB Manufacturing and the required libraries; flash a minimal test sketch for each module separately.
4. Write the main firmware: read sensors → process → drive outputs / send data.
5. Configure network or cloud credentials and test communication end-to-end.
6. Calibrate thresholds, add error handling (reconnect, sensor time-out) and run a long-duration test.
7. Finalise on a PCB / enclosure and document wiring, code and results.

Key Features
- Correct wiring and bus configuration
- Driver setup
- Data processing
- Verification on real hardware

Expected Output
On completion the student will have a working peripheral that is measured/driven exactly as intended.

Deliverables
- Complete source code with comments
- Circuit diagram and pin mapping
- Project report with screenshots and results
- Demonstration-ready build