35 lines
1.2 KiB
Python
35 lines
1.2 KiB
Python
# SPDX-FileCopyrightText: 2017 Limor Fried/ladyada for Adafruit Industries
|
|
# SPDX-FileCopyrightText: 2017 Phillip Burgess for Adafruit Industries
|
|
#
|
|
# SPDX-License-Identifier: MIT
|
|
|
|
"""
|
|
Adafruit Trinket/Gemma Example: Simple Theramin
|
|
Read the voltage from a Cadmium Sulfide (CdS) photocell voltage
|
|
divider and output a corresponding tone to a piezo buzzer
|
|
|
|
Photocell voltage divider center wire to GPIO #2 (analog 1)
|
|
and output tone to GPIO #0 (digital 0)
|
|
"""
|
|
|
|
import time
|
|
|
|
import analogio
|
|
import board
|
|
import pwmio
|
|
|
|
photocell_pin = board.A1 # CdS photocell connected to this ANALOG pin
|
|
speaker_pin = board.D0 # Speaker is connected to this DIGITAL pin
|
|
scale = 0.03 # Change this to adjust tone scale
|
|
|
|
# Initialize input/output pins
|
|
photocell = analogio.AnalogIn(photocell_pin)
|
|
pwm = pwmio.PWMOut(speaker_pin, variable_frequency=True, duty_cycle=0)
|
|
|
|
while True: # Loop forever...
|
|
# Read photocell analog pin and convert voltage to frequency
|
|
pwm.frequency = 220 + int(scale * float(photocell.value))
|
|
pwm.duty_cycle = 32767 # 50% duty cycle
|
|
time.sleep(0.4) # Play for 400 ms (adjust to your liking)
|
|
pwm.duty_cycle = 0 # Stop playing
|
|
time.sleep(0.05) # Delay 50 ms between notes (also adjustable)
|