Gemma M0 - Color Wheel

code.py

# Gemma IO demo
# Welcome to CircuitPython 5 :)

import usb_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
from adafruit_hid.keycode import Keycode
from digitalio import DigitalInOut, Direction, Pull
from analogio import AnalogIn, AnalogOut
from touchio import TouchIn
import adafruit_dotstar as dotstar
import microcontroller
import board
import time
import random

# One pixel connected internally!
dot = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=0.2)

# Built in red LED
led = DigitalInOut(board.D13)
led.direction = Direction.OUTPUT

# Analog output on A0
aout = AnalogOut(board.A0)

# Analog input on A1
analog1in = AnalogIn(board.A1)

# Capacitive touch on A2
touch2 = TouchIn(board.A2)

# Helper to convert analog input to voltage
def getVoltage(pin):
    return (pin.value * 3.3) / 65536


# Helper to give us a nice color swirl
def wheel(pos):
    # Input a value 0 to 255 to get a color value.
    # The colours are a transition r - g - b - back to r.
    if pos < 0:
        # time.sleep(1)
        return [0, 0, 0]
    if pos > 255:
        # time.sleep(1)
        return [0, 0, 0]
    if pos < 85:
        # time.sleep(1)
        return [int(pos * 3), int(255 - (pos * 3)), 0]
    elif pos < 170:
        # time.sleep(1)
        pos -= 85
        return [int(255 - pos * 3), 0, int(pos * 3)]
    else:
        # time.sleep(1)
        pos -= 170
        return [0, int(pos * 3), int(255 - pos * 3)]

i = 0
while True:
    # spin internal LED around!
    dot[0] = wheel(i)
    dot.show()

    # set analog output to 0-3.3V (0-65535 in increments)
    aout.value = 100 * 256
    led.value = touch2.value
    i = (i + 1) % 256  # run from 0 to 255