Import the code

light.py

@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: MIT
+#
+# Little christmas candle
+#
+# Author:    Nils Freydank <nils.freydank@datenschutz-ist-voll-doof.de>
+# Year:      2022
+# Copyright: MIT
+
+import machine
+import time
+
+pin_led1 = machine.Pin(22)
+pin_led2 = machine.Pin(10)
+pin_led3 = machine.Pin(8)
+
+
+def _get_new_duty(
+    factor: int, signed_step_width: int, limit_lower: int, limit_upper: int
+) -> Tuple[int, int]:
+    duty_fac: int = factor
+
+    duty_fac += signed_step_width
+    if duty_fac > limit_upper:
+        duty_fac = limit_upper
+        signed_step_width = (-1) * signed_step_width
+    elif duty_fac < limit_lower:
+        duty_fac = limit_lower
+        signed_step_width = (-1) * signed_step_width
+
+    return duty_fac, signed_step_width
+
+
+def flicker() -> None:
+    pwm_led1 = machine.PWM(pin_led1)
+    pwm_led2 = machine.PWM(pin_led2)
+    pwm_led3 = machine.PWM(pin_led3)
+
+    pwm_led1.freq(1_000)
+    pwm_led2.freq(1_000)
+    pwm_led3.freq(1_000)
+
+    duty_fac_led1: int = 0
+    signed_step_width_led1: int = 1
+    duty_fac_led2: int = 0
+    signed_step_width_led2: int = 1
+    duty_fac_led3: int = 0
+    signed_step_width_led3: int = 1
+
+    delay_s: float = 0.01
+
+    while True:
+        duty_fac_led1, signed_step_width_led1 = _get_new_duty(
+            duty_fac_led1, signed_step_width_led1, 240, 250
+        )
+        pwm_led1.duty_u16(duty_fac_led1**2)
+
+        duty_fac_led2, signed_step_width_led2 = _get_new_duty(
+            duty_fac_led2, signed_step_width_led2, 0, 200
+        )
+        pwm_led2.duty_u16(duty_fac_led2**2)
+
+        duty_fac_led3, signed_step_width_led3 = _get_new_duty(
+            duty_fac_led3, signed_step_width_led3, 30, 100
+        )
+        pwm_led2.duty_u16(duty_fac_led3**2)
+
+        time.sleep(delay_s)
+
+
+# vim:fileencoding=utf-8:ts=4:syntax=python:expandtab

main.py

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: MIT
+#
+# Little christmas candle
+#
+# Author:    Nils Freydank <nils.freydank@datenschutz-ist-voll-doof.de>
+# Year:      2022
+# Copyright: MIT
+
+import _thread
+
+from light import flicker
+from music import play_music
+
+if __name__ == "__main__":
+    _thread.start_new_thread(flicker, ())
+    play_music()
+
+# vim:fileencoding=utf-8:ts=4:syntax=python:expandtab

music.py

@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: MIT
+#
+# Little christmas candle
+#
+# Author:    Nils Freydank <nils.freydank@datenschutz-ist-voll-doof.de>
+# Year:      2022
+# Copyright: MIT
+
+import json
+import machine
+import time
+
+pin_piezo = machine.Pin(12)
+
+
+def _note_to_freq(note_name: str) -> int:
+    """
+    Translate note names from strings into frequency values.
+    """
+    freq: int = 0
+
+    # frequencies, see e.g.
+    # https://en.wikipedia.org/wiki/Piano_key_frequencies
+    note_names: dict = {
+        "c4": 262,
+        "cis4": 277,
+        "d4": 294,
+        "e4": 330,
+        "f4": 349,
+        "fis4": 370,
+        "g4": 392,
+        "a4": 440,
+        "b4": 466,
+        "h4": 494,
+        "c5": 523,
+        "cis5": 554,
+        "d5": 587,
+        "e5": 659,
+        "f5": 698,
+        "fis5": 740,
+        "g5": 784,
+        "a5": 880,
+        "b5": 923,
+        "h5": 988,
+        "c6": 1047,
+    }
+
+    try:
+        freq = note_names[note_name]
+    except KeyError:
+        freq = -1
+        print(f"exc in _note_to_freq() for {note_name}.")
+
+    return freq
+
+
+def _len_to_second(len_name: str, len_scaling: float = 0.6) -> float:
+    time: float = 0.0
+
+    len_names = {
+        "_t": 0.125 * len_scaling,  # thirty-second note or pause
+        "_s": 0.25 * len_scaling,  # sixteenth note or pause
+        "_e": 0.5 * len_scaling,  # eight note or pause
+        "_q": 1.0 * len_scaling,  # quarter note or pause
+        "_h": 2.0 * len_scaling,  # half note or pause
+        "_f": 4.0 * len_scaling,  # whole note or pause
+    }
+    try:
+        for elem in len_name.split("+"):
+            time += len_names[elem.replace(" ", "")]
+    except KeyError:
+        time = 0.0
+        print(f"exc in _len_to_second() for {elem}.")
+        print("Do you have a typo there, e.g. 'a' + 'b' instead of 'a + b'?")
+
+    return time
+
+
+def play_note(note_name: str, duration: str, loud: bool = False) -> int:
+    if loud:
+        duty_cycle: int = 16_000
+    else:
+        duty_cycle: int = 400
+    real_pwm_freq: int = 0
+
+    pwm_piezo = machine.PWM(pin_piezo)
+    pwm_piezo.freq(_note_to_freq(note_name))
+    real_pwm_freq = pwm_piezo.freq()
+
+    pwm_piezo.duty_u16(duty_cycle)
+
+    time.sleep(_len_to_second(duration))
+    pwm_piezo.duty_u16(0)
+    time.sleep(0.05)
+
+    return real_pwm_freq
+
+
+def pause(duration: str) -> None:
+    time.sleep(_len_to_second(duration))
+    time.sleep(0.05)
+
+
+def play_music(file_name: str = "o-tannenbaum.json") -> None:
+    data: dict = {}
+
+    try:
+        with open(file_name, "r") as f:
+            data = json.load(f)
+
+        try:
+            if data["metadata"]["format"] == "json-0.1.0":
+                for notes in data["music"]:
+                    for note in notes.keys():
+                        if note == "0":
+                            pause(notes[note])
+                        else:
+                            play_note(note, notes[note])
+            elif data["metadata"]["format"] == "json-0.2.0":
+                pass
+
+        except:
+            print(f"play_oh_tannnebaum() failed to parse {data}.")
+
+    except FileNotFoundError:
+        print("Could not load the JSON file containing the song's details.")
+
+
+# vim:fileencoding=utf-8:ts=4:syntax=python:expandtab