The Arduino Nano uses a bootloader for handling programming the MCU, which requires the USB to serial bridge to be disconnected from anything that could interfere with the programming.

The Arduino Nano and Raspberry Pi Pico support different input voltages, so they also use different power sources. However, they can both be powered with a 5V supply via their onboard USB ports.

Both the Arduino Nano and Uno can be powered via their integrated USB connectors. This automatically supplies regulated 5V power to the board, allowing you to use any USB-supported power source ...

Adafruit has announced the launch of a new product today in the form of the VERTER power converter, which has been created to convert just about any battery pack to 5V for just $9.95 ...