# SPDX-FileCopyrightText: 2018 Collin Cunningham for Adafruit Industries # # SPDX-License-Identifier: MIT import board from rainbowio import colorwheel import neopixel from analogio import AnalogIn n_pixels = 10 # Number of pixels you are using dc_offset = 0 # DC offset in mic signal - if unusure, leave 0 noise = 100 # Noise/hum/interference in mic signal lvl = 10 # Current "dampened" audio level maxbrt = 127 # Maximum brightness of the neopixels (0-255) wheelStart = 0 # Start of the RGB spectrum we'll use wheelEnd = 255 # End of the RGB spectrum we'll use mic_pin = AnalogIn(board.A7) # Set up NeoPixels and turn them all off. strip = neopixel.NeoPixel(board.NEOPIXEL, n_pixels, brightness=0.1, auto_write=False) strip.fill(0) strip.show() def remapRangeSafe(value, leftMin, leftMax, rightMin, rightMax): # this remaps a value from original (left) range to new (right) range # Force the input value to within left min & max if value < leftMin: value = leftMin if value > leftMax: value = leftMax # Figure out how 'wide' each range is leftSpan = leftMax - leftMin rightSpan = rightMax - rightMin # Convert the left range into a 0-1 range (int) valueScaled = int(value - leftMin) / int(leftSpan) # Convert the 0-1 range into a value in the right range. return int(rightMin + (valueScaled * rightSpan)) while True: n = int((mic_pin.value / 65536) * 1000) # 10-bit ADC format n = abs(n - 512 - dc_offset) # Center on zero if n >= noise: # Remove noise/hum n = n - noise # "Dampened" reading (else looks twitchy) - divide by 8 (2^3) lvl = int(((lvl * 7) + n) / 8) # Color pixels based on rainbow gradient vlvl = remapRangeSafe(lvl, 0, 255, wheelStart, wheelEnd) for i in range(0, len(strip)): strip[i] = colorwheel(vlvl) # Set strip brightness based oncode audio level brightness = remapRangeSafe(lvl, 50, 255, 0, maxbrt) strip.brightness = float(brightness) / 255.0 strip.show()