Alun Morris’s Offline-Wikipedia using ESP32 is an open-source project that turns the inexpensive ESP32-2432S028, commonly called the “Cheap Yellow Display” or CYD, into a standalone Wikipedia reader. The hardware combines an ESP32 microcontroller with a 320×240 ILI9341 color display, an XPT2046 touchscreen, and a microSD card interface. Instead of depending on Wi-Fi or cloud services, the device stores Wikipedia content locally and displays it directly on the embedded screen.
The project uses a Kiwix ZIM database as its content source, with the Simple English Wikipedia edition being especially suitable for the device. Articles, images, and a full-text search index are stored on the microSD card, allowing users to search and browse the encyclopedia without an internet connection. The Simple English dataset is reported to contain approximately 285,000 articles and require around 3.3 GB of storage, making it practical for a modern microSD card, while the much larger full English Wikipedia may exceed the system’s storage and performance limits.
From a technical perspective, the repository includes the ESP32 firmware, preprocessing tools, and setup instructions needed to convert the original offline Wikipedia data into a format that can be accessed efficiently by a microcontroller. On first boot, the touchscreen can be calibrated, with the calibration data saved for future use. This project is a strong example of edge computing and embedded information systems: a low-cost microcontroller, local storage, and a simple graphical interface combine to provide useful knowledge completely offline. It could also serve as a foundation for additional features such as random-article browsing, bookmarks, multilingual content, or integration with other offline educational resources.
