Pico W Quick Reference

Pico W Quick Reference

Flashing MicroPython, Thonny setup, REPL, and pin notes.

Flashing MicroPython
Hold BOOTSEL + plug USB Enter mass storage mode ߀” board appears as RPI-RP2 drive
Drop .uf2 onto RPI-RP2 MicroPython firmware is flashed and board reboots automatically
Download from micropython.org/download/rp2-pico-w/ Always get the Pico W firmware ߀” not the plain Pico version
main.py runs at boot Save your program as main.py on the Pico W to auto-run on power-on
Thonny IDE
Tools ߆’ Options ߆’ Interpreter Set to MicroPython (Raspberry Pi Pico)
F5 ߀” Run current script Run on the Pico W from your PC
File ߆’ Save as ߆’ Raspberry Pi Pico Save file directly onto the board flash
Shell / REPL at bottom Interactive Python prompt ߀” type commands and see instant results
MicroPython Basics
from machine import Pin Import GPIO Pin class
from time import sleep Import sleep (seconds) and sleep_ms / sleep_us
import gc; gc.collect() Run garbage collection to free memory
gc.mem_free() Check available heap memory in bytes
Pin Notes
Pin("LED") Built-in green LED on Pico W (via CYW43 chip)
3.3 V logic only Pico W is NOT 5 V tolerant on any GPIO
GPIO ߉  header pin number GPIO 15 is not at position 15 ߀” always check the pinout diagram
ADC pins: GPIO 26߀“28 Only these three GPIO pins support analog input