Except, on the Micro, there is no actual serial bus involved in programming the Arduino, as everything is done over USB. So the TX and RX leds are driven by a couple of pins on the ATmega32U4 (see a ...

Wyatt]’s CPUVolt library provides a fast way to measure voltage using no external components, and no I/O pin. It only applies to certain microcontrollers, but he provides example Arduino code ...

PD Micro is the first Arduino-compatible board with USB Type-C Power Delivery, which allows your project to make use of voltages from 5-20 V. It’s perfect for projects that would require ...

Microduino actually isn't the smallest Arduino clone on the market. The Femtoduino, boasting the "same power and pin count of an Arduino Uno," measures just 0.81" × 0.6".