CircuitPython Experiments

Blinky

import board, digitalio, time

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT

while True:
    led.value = not led.value
    time.sleep(0.5)

Pulled-Up Button

import board, digitalio, time

btn = digitalio.DigitalInOut(board.D10)
btn.switch_to_input(pull=digitalio.Pull.UP)

while True:
    print(not btn.value)
    time.sleep(0.1)

I2C Scanner

import board, busio, time

# i2c = board.I2C()
i2c = busio.I2C(board.SCL, board.SDA)

while not i2c.try_lock():
    pass

print(i2c.scan())

Files

• neopixel.py: a demo for NeoPixel LEDs. Requires neopixel.mpy in the drivers bundle.
• audiomixer.py: a demo of using audiomixer to play multiple audio files
• hd44780.mpy: driver for I2C LCD1602. Fixed I2C timing and converted from bablokb/circuitpython-hd44780.

import busio, board
from hd44780 import HD44780

i2c = busio.I2C(scl=board.SCL, sda=board.SDA, frequency=400000)
display = HD44780(i2c=i2c, address=0x27)

display.clear()
display.write('Hello', 1)
display.write('World', 2)

Resource Links

• Firmware download
• Bootloader (SAMD21/51)
• CircuitPython Essentials
• CircuitPython Essentials Examples
• CircuitPython API Reference
• Circuit Playground Express CircuitPython API Reference
• Circuit Playground Driver bundle (py/mpy and examples)
• font5x8.bin is here