frequency.py

import RPi.GPIO as GPIO
import time

buzzerpin = 4 # pin the PWM Signal will run on, separate from GND / VCC
start_epoch = time.time()

# Sets up the GPIO and PWM frequency stuff
def setup():
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)
    GPIO.setup(buzzerpin, GPIO.OUT)
    
    global Buzzer, allocated_time
    Buzzer = GPIO.PWM(buzzerpin, 500) # PWM on buzzerpin pin, initial 500 frequency
    Buzzer.start(50) # drop out
    allocated_time = 999 # Allocated time, while not erroring, the script will run for

# Cleanup function
def destroy():
    Buzzer.stop()
    GPIO.cleanup()

# This loops whilst we're under the allocated time
def loop():
  # Buzzer.ChangeFrequency()
  pass

# Returns true if we've passed the allocated time
def past():
    cur = time.time()
    dif = cur - start_epoch
    if dif >= allocated_time:
        return True
    return False

if __name__ == '__main__':
    try:
        setup()
        while not past():
            loop()
    except:
      raise
    finally:
        destroy()