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Flash firmware

A brand-new board often arrives empty. This page shows you how to put MicroPython onto it using Snakie's built-in flasher, so your board is ready to run your code.

What is firmware?

Firmware is the base software that lives on the board itself. MicroPython is the firmware here — it is the program that lets your board understand Python. Learn more in What is MicroPython?.

Flashing replaces what is on the board

Flashing installs fresh firmware over the top of whatever is already there. Any MicroPython files you saved on the board can be wiped, so copy anything you want to keep to your computer first.

Open the flasher

Click the ⚡ Flash firmware button on the right of the status bar (the strip along the bottom of the window).

Snakie looks for connected boards automatically. Press ⟳ Detect at any time to scan again after you plug a board in.

📸 Screenshot

Show: the Flash firmware dialog with a detected board and the Board type dropdown open.

1. Pick your board

Choose your board from the Board type list:

Board How it flashes
RP2040 / Pico (UF2) Copies a .uf2 file to a special drive
ESP32 / ESP8266 (esptool) Flashes over the serial (USB) port
BBC micro:bit (.hex) Copies a .hex file to the micro:bit drive

Not sure your board is in the list? See Supported boards.

2. Choose the firmware

Pick where the firmware comes from:

  • Download from MicroPython.org — choose a Family → Model → Variant → Version and Snakie fetches the correct file for you. This is the easy choice.
  • Local file — browse to a firmware file you already downloaded (.uf2, .bin or .hex).

3. Flash it

  1. Unplug the board.
  2. Hold down the BOOTSEL button while you plug it back in, then let go.
  3. A drive called RPI-RP2 appears — pick it in the dialog.
  4. Press Flash. Snakie copies the file across and the board reboots into MicroPython.
  1. Pick the serial port for your board.
  2. Leave the flash offset as filled in.
  3. Press Flash.

esptool needed

ESP boards flash with a helper called esptool. If the dialog says it is missing, install it once from a terminal: 

pip install esptool

  1. Pick the MICROBIT drive.
  2. Press Flash.

Warning

If you see a MAINTENANCE drive instead, unplug and replug without holding the reset button. Flashing in maintenance mode can break the board, so Snakie will not let you.

A progress bar and a live log show each step. When it finishes, press Done.

Try it out

Now connect to your board, open the shell, and toggle the onboard LED to check MicroPython is running:

from machine import Pin
import time

led = Pin("LED", Pin.OUT)
while True:
    led.toggle()
    time.sleep(0.5)

The light should blink on and off. 🎉

Keeping firmware up to date

When a board is connected, Snakie can tell you if a newer MicroPython is available and offer to update it from the same ⚡ button. You can switch this on or off in Settings ▸ Editor ▸ Firmware updates.

Tip

You only need to flash firmware once (or when you want a newer version). After that, just connect and start coding.