Test It!

Most CircuitPython boards have an LED built into the board, which makes testing very easy! Create a blank document named code.py in the CIRCUITPY drive.

Open the file with your editor of choice (e.g. Notepad on Windows, TextEdit on macOS), and enter the following code:

import board
import digitalio
import time

pin_name = board.L

led = digitalio.DigitalInOut(pin_name)
led.direction = digitalio.Direction.OUTPUT
while True:
    led.value = True
    time.sleep(0.1)
    led.value = False
    time.sleep(0.1)

Note! You might have to change board.L to another value. Find your board in the list below to see which value you should use.

Save the program. Your board should reset automatically, and the onboard LED should begin blinking rapidly.

If you see the LED flashing, you know that CircuitPython is up and running on your board!

WARNING! Make sure you unmount the CIRCUITPY drive before resetting or unplugging your CircuitPython-enabled board (especially on Windows). Some operating systems (like Windows) have delayed writes to drives, which could corrupt the filesystem on the board. If this happens, you will need to reinstall CircuitPython.
This guide was first published on Dec 14, 2018. It was last updated on Dec 14, 2018. This page (Test It!) was last updated on Aug 18, 2019.