CPX Circuit Python: Super-quick start (with “Blink” demo code)
Based on the Adafruit tutorial.
- Connect the CPX (Circuit Playground Express) and make sure it’s ready to be programmed (green lights). Single- or double-click RESET; whichever works. CPLAYBOOT should appear on the desktop.
- Download Circuit Python for CPX to CPLAYBOOT. If successful, new drive CIRCUITPY will appear.
- Now download this sample Python program to CIRCUITPY as code.py.
Here’s what the code looks like:
import board import digitalio import time led = digitalio.DigitalInOut(board.D13) led.direction = digitalio.Direction.OUTPUT while True: led.value = True time.sleep(0.5) led.value = False time.sleep(0.5)
The red LED should be blinking.
To go back to MakeCode, double-click RESET and load new program as usual into CPLAYBOOT.
Using the Mu editor
- Download Portamu to Desktop (it’s kinda big).
- Double-click the downloaded zip file to unpack the editor.
- Start Portamu.
- Be sure “Mode” is set to “Adafruit”.
- Click “New”, then cut and paste the following:
led = digitalio.DigitalInOut(board.D13)
led.direction = digitalio.Direction.OUTPUT
led.value = True
led.value = False
- “Check” before you try to save. Editor is finicky, but that’s good!
- “Save”, always as “code.py” to CIRCUITPY. (Once you select a file to save to, you can’t change it except by starting a new program.)
You should see the red LED blinking again.
Now try this code:
from adafruit_circuitplayground.express import cpx
x, y, z = cpx.acceleration
print((x, y, z))
Be sure to Save as code.py into CPLAYBOOT.
Hmm, not much is happening. Click the “Serial” button in the editor.
A window labelledAdafruit CircuitPython REPL” opens at the bottom and you can see the CPX reporting its orientation every half-second.
Using interactive Python
- Click “Serial” in the mu editor if you haven’t already..
- Click in the “Adafruit CircuitPython REPL” window, type Control-C (yes, “Control”, even on Macs). Then press any key. You will see the prompt for interactive Python.
- You can use it as a calculator. Try typing in some simple arithmetic.
- Type Control-D to exit to Console.
Now check out the Circuit Python for CPX guide, with lots of cut and paste code
Online Python for Beginners