Personalised DIY E-Paper Clock Using ESP32 Microcontroller

The Personalised DIY E-Paper Clock operates by coordinating timekeeping, processing, and visual output across several interconnected hardware modules. At the core of the system is the ESP32 microcontroller (MOD1), which manages the overall logic and coordinates data updates. Because accurate timekeeping is critical for a clock, the system relies on an external DS3231 Real-Time Clock module (MOD3) to track hours, minutes, and seconds independently, maintaining precision even if the main processor enters low-power states. To ensure a stable and reliable power supply, input voltage is regulated down to a steady 3.3 volts by the HT7333A voltage regulator (IC1), supported by two 10 microfarad 16-volt electrolytic capacitors (C1, C2) that filter out voltage spikes and smooth out transient current demands. When the time changes or a display refresh is triggered, the ESP32 sends updated image data to the large 19-centimeter (7.5-inch) black-and-white e-paper display (MOD2). Unlike traditional LCD or LED screens, the e-paper display only draws power when its image is actively changing; once the tiny microcapsules inside the panel shift to form the text or graphics, they retain that visual state indefinitely without consuming any electrical current. This unique characteristic allows the system to remain in ultra-low power states for extended periods, making it ideal for continuous, battery-friendly operation.