Build Your Own Simple Smartwatch

The Simple Smartwatch system centers around the IndusBoard Coin microcontroller, which acts as the core processing unit for gathering sensor data and rendering the graphical user interface. To monitor vital signs, the device integrates a MAX30100 sensor module, which utilizes optical plethysmography—emitting specific wavelengths of light through the skin to measure changes in light absorption caused by pulsating blood flow, thereby calculating both heart rate and blood oxygen saturation (SpO2). Body temperature data is captured via an integrated temperature sensor wired into the microcontroller. Once raw measurements are processed by the ESP32-based IndusBoard Coin, the user interface and real-time health metrics are outputted visually to a vibrant GC9A0 display screen, allowing the wearer to view their vital signs directly on the wrist. Communication between the microcontroller and its peripheral sensors relies on standard digital communication protocols, while power management and physical assembly are achieved using connecting wires and standard soldering equipment to secure the hardware into a cohesive, wearable unit programmed via the Arduino IDE.