Serial Ports (USB and UART)¶
The Arduino-Pico core implements a software-based Serial-over-USB port using the USB ACM-CDC model to support a wide variety of operating systems.
Serial is the USB serial port, and while
Serial.begin() does allow
specifying a baud rate, this rate is ignored since it is USB-based.
(Also be aware that this USB
Serial port is responsible for resetting
the RP2040 during the upload process, following the Arduino standard
of 1200bps = reset to bootloader).
The RP2040 provides two hardware-based UARTS with configurable pin selection.
Configure their pins using the
setXXX calls prior to calling
Serial1.setRX(pin); Serial1.setTX(pin); Serial1.begin(baud);
For detailed information about the Serial ports, see the Arduino Serial Reference .