The ESP32-C3 SuperMini Expansion Board is a specialized companion PCB designed to solve the limitations of the ultra-compact ESP32-C3 SuperMini development board. It bridges the gap between the tiny, space-saving microcontroller and the practical requirements of prototyping, battery management, and sensor integration. Key Features & Hardware Specifications: Integrated Battery Management: It features a built-in lithium battery charger (typically utilizing the LTH7R chip) paired with a PH2.0 JST connector. This allows you to plug in a standard 3.7V LiPo or lithium-ion battery directly to achieve power independence. Charging Diagnostics: The board includes onboard status LEDs (typically green or blue depending on the factory revision) that indicate when the battery is actively charging via the microcontroller’s main USB port. Color-Coded SVG Header Rails: Rather than dealing with crowded breadboards, it breaks out every available GPIO pin into standard, organized triple-pin headers (Signal, Voltage, Ground). This simplifies connecting multiple peripheral modules. Dual Power Outlines (VCC1 and VCC2): Features an S201 voltage regulator to handle low-power regulation. It outputs standard 3.3V and 5V power rails. The factory default output for the configurable power zones is 3.3V, but you can bridge specific pads on the back of the PCB to output higher voltages. Physical Dimensions: It measures an incredibly compact 37.4mm × 22.53mm, keeping your project footprint minimal for wearables and small IoT enclosures. Why Prototypers Use It: While the standalone ESP32-C3 SuperMini board is highly valued for its size, it lacks integrated battery charging circuits and features very few power pins. Using this expansion board eliminates the need for separate external 5V/3.3V step-up or step-down modules and external TP4056 battery charger boards. It makes the SuperMini behave like a fully-featured, battery-powered development kit for remote IoT sensors and smart clothing.