The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52.

It’s a significant update. The Arduino UNO and Arduino Mega 2560 update the Duemilanove and Mega respectively. They now use an ATMega8U2 instead of an FTDI USB to serial converter chip.

FTDI’s FT231XS takes care of USB connectivity. The board has a micro-USB connector rather than the bulkier type B used on UNOs. As per UNO, NerO has 14 digital interface pins plus six analogue inputs.

An FTDI Chip FT810 embedded video engine (EVE) IC powers the HMI operation, while a low-power, 3.1 DMIPs/MHz FT903 Super-Bridge microcontroller offers access to an Arduino Uno over SPI and a central ...