Installing CircuitPython is easy and it allows you to write code in the language designed specifically to work with Circuit Playground Express.
Click the button below to open the Circuit Playground Express page on CircuitPython.org.
Click the DOWNLOAD .UF2 NOW button near the top of the page. Save the UF2 file to a convenient location on your computer.
Use the micro USB cable to connect Circuit Playground Express to a free USB port on your computer.
Once connected, Circuit Playground Express will begin running its default code. You should see the built-in neopixel LEDs light up and start animating. Pressing the large button on the left side of the board will play a simple melody.
Press the small Reset button in the middle of the board once. You should see all of the LEDs turn green.
A new drive will appear on your computer named CPLAYBOOT.
Copy the CircuitPython .uf2 file to your Circuit Playground Express by dragging and dropping it onto the CPLAYBOOT drive.
After the file is copied, the CPLAYBOOT drive will disappear and a CIRCUITPY drive will appear in its place.
That's all - you've successfully installed CircuitPython on your Circuit Playground Express!