The Exen Mini was categorized as one of the world’s smallest 32-bit Arduino compatible boards that was launched by Nerdonic, although the board was able to get the job done in some areas it still had limited capacity, it had only 8 I/O pins. Based on the success and limitations of the Exen Mini, Nerdonic has launched a new similar board, but with improved I/O options called the Exen Proto.
The Exen Proto is a small 32-bit Arduino compatible board based around the Arduino Zero bootloader, so projects built for the Arduino Zero won’t have problems working on the Exen Proto. The Exen Proto board is also breadboard compatible, meaning it will comfortably fit into a standard breadboard without the need for any extra connectors or manipulation.
The board is pretty small as compared to the likes of Arduino Zero and big as compared to its predecessor Exen Mini, it measures for about 14.9 x 29.8 mm and weighs just about 1.1 grams. It comes with 256KB of ROM (Program Memory), 32KB of RAM, processing speed of up to 48MHz, and up 20 I/O pins. The I/O pins include 19x PWM, 11x ADC (Analog), Serial, SPI, I2C and Digital pins. The Exen Proto can be powered by either the Micro USB port, 3.3v to 20v input pin (regulated to 3.3v with a 3.3v output pin), or directly to the 3.3v pin.
The board can be programmed with the Arduino IDE thanks to the pre-flashed Arduino Zero bootloader . The Exen Proto board is expected to come with some add-ons board or shields like a Li-Ion/Li-Po charge and discharge shield that can be charged by either the power pin or the USB port on the Exen Proto.