Running the RTTTL music example

Run the code in the chapter08/passive_buzzer_rtttl.py file, and your buzzer will play a simple musical scale.

The code to perform this is quite simple. In line (1) in the following code, we are using the rtttl module to parse an RTTTL music score into a series of notes defined by frequency and duration. Our score is stored in the rtttl_score variable:

from rtttl import parse_rtttl
rtttl_score = parse_rtttl("Scale:d=4,o=4,b=125:8a,8b,        # (1)
    8c#,8d,8e,8f#,8g#,8f#,8e,8d,8c#,8b,8a")

Next, in line (2), we loop through the parsed notes in rtttl_score and extract the frequency and duration:

    for note in rtttl_score['notes']:                        # (2)
        frequency = int(note['frequency'])
        duration = note['duration'] # Milliseconds
        pi.hardware_PWM(BUZZER_GPIO, frequency, duty_cycle)  # (3)
        sleep(duration/1000)                                 # (4)

In line (3), we set the frequency...