Waveshare’s New $27 ESP32-S3 Board Features a Unique ePaper-Like RLCD

Whether you’re a seasoned electronics engineer or just starting out as a hobbyist, it’s a good idea to have a few all-in-one development boards on hand. When inspiration strikes, the last thing you want to do is spend weeks designing a circuit and waiting for the parts to be shipped to your door. You want to strike while the iron is hot and turn that great idea into a reality. By integrating many commonly used components into a single package, all-in-one boards make prototyping fast and easy.

If you could use a new all-in-one board in your toolbox, you should take a look at the ESP32-S3 4.2-inch RLCD Development Board that was just released by Waveshare. It combines a powerful microcontroller with a very unique display technology, along with plenty of options for interfacing. Currently, the device is selling for just $27.

As the name implies, Waveshare’s latest creation is powered by an ESP32-S3 microcontroller. This dual-core Xtensa LX7 processor can run at up to 240 MHz and includes built-in Wi-Fi and Bluetooth 5 connectivity, making it well suited for modern IoT and connected applications. The board comes with 16 MB of onboard Flash and 8 MB of PSRAM, providing ample memory headroom for graphics, audio processing, and network stacks.

One of the most interesting features is the 4.2-inch reflective liquid crystal display (RLCD), which offers a 300×400 resolution in black and white. Unlike traditional LCDs, the RLCD uses ambient light instead of a backlight, resulting in an ePaper-like reading experience with very low power consumption and fast refresh times. This makes it particularly attractive for always-on dashboards, electronic calendars, and outdoor or brightly lit environments where conventional displays struggle with glare.

Beyond the display, the board is packed with peripherals that would normally require multiple add-on modules. An onboard audio subsystem includes a low-power audio codec, dual microphones, and a speaker header, enabling advanced audio features such as noise reduction, echo cancellation, and AI voice interaction.

Environmental sensing and timekeeping are also built in, thanks to an SHTC3 temperature and humidity sensor and a PCF85063 real-time clock. Storage expansion is handled via a TF card slot, while power can be supplied by USB-C or an onboard 18650 lithium battery holder, complete with charging and protection circuitry.

With support for both ESP-IDF and the Arduino IDE, plus plenty of exposed GPIO, UART, I2C, and SPI interfaces, the ESP32-S3 4.2-inch RLCD Development Board is clearly aimed at rapid prototyping. Whether you’re building a smart desktop ornament, an AI assistant, or experimenting with low-power display technologies, this board offers an unusually complete starting point at a very accessible price.