phyduino/02_digital/tone_pitch_follower/main.py

Plays a pitch on a piezo buzzer on D8 that follows the voltage on A0, from 120 Hz at 0 V to 1500 Hz at 3.3 V, and prints the reading and the pitch.

Wiring

A piezo buzzer between D8 and GND, and a potentiometer wiper (ends on GND and 3.3 V) or a light sensor divider on A0.

Uses

pwm(), analog_read()

# Plays a pitch on a piezo buzzer on D8 that follows the voltage on A0, from
# 120 Hz at 0 V to 1500 Hz at 3.3 V.
#
# Connect a piezo buzzer between D8 and GND, and a potentiometer wiper (ends
# on GND and 3.3 V) or a light sensor divider to A0.
 
import time  # sleep_ms() for pauses
 
import phyduino as mcu  # the Phyduino Pico library, used as mcu.<name>
 
LOW_HZ = 120  # pitch at 0 V
HIGH_HZ = 1500  # pitch at 3.3 V
 
buzzer = mcu.pwm("D8", duty_u16=32768)  # Puts D8 into PWM mode at half duty and saves the control variable to the 'buzzer' variable.
 
while True:  # repeats until stopped: Interrupt in PyCharm, or mpremote soft-reset
    reading = mcu.analog_read("A0")  # 0 (0 V) to 4095 (3.3 V)
    pitch = LOW_HZ + reading * (HIGH_HZ - LOW_HZ) // 4095  # scale 0-4095 to LOW_HZ-HIGH_HZ; // divides to a whole number
    print(reading, pitch)
    buzzer.freq(pitch)  # change the pitch
    time.sleep_ms(10)  # a short pause between readings