Catnip Electronics' Paper WiFI Is a Compact, Connected ESP32-C3 ePaper Display
Powered by two AA batteries and featuring an ePaper display, this compact desktop tool includes an on-board environmental sensor.
Lithuanian maker Albertas Mickėnas has put together a compact ePaper device designed for low-power connected display projects: the Espressif ESP32-C3-powered Paper WiFi.
"This is a pre-packaged solution for all the cases when you need a low power display for your sensor data with Wi-Fi or BLE [Bluetooth Low Energy] connectivity — to exchange data with online services or provide it to mobile apps," Mickėnas explains of the board's design. "The board is easy to program via USB cable using PlatformIO, [and the] code is Arduino compatible."
Built around the Espressif ESP32-C3 system-on-chip, the Paper WiFi features a single 32-bi RISC-V microcontroller core running at up to 160MHz, 400kB of static RAM (SRAM), 2.4GHz Wi-Fi and Bluetooth 5.0 Low Energy (BLE) radios, and a series of general-purpose input-output (GPIO) pins — of which the Paper WiFi makes two, plus a UART bus, available to the user.
The device is designed primarily for use with external I2C hardware, providing an I2C port with switched power — though the board also includes a Sensirion SHT40 relative humidity and temperature sensor, giving it the ability to work as an environmental monitoring display with no extra hardware required.
The display, meanwhile, is a 2.13" 212×104 ePaper unit — providing only black and white imagery and with a relatively low resolution, but boasting the big advantage that power is only required when the imagery is being changed. When the display is static, it draws no power — making the most of the two AA batteries used to give it untethered operation.
Mickėnas is selling the Paper WiFi on the Catnip Electronics Tindie store at $42 or $59 with optional 3D-printed case; design files and source code, meanwhile, are available on GitHub under an unspecified open-source license.