buzzer example addopted

examples/14-buzzer/main.py

@@ -0,0 +1,37 @@
+# Source:
+# https://micropython-on-wemos-d1-mini.readthedocs.io/en/latest/basics.html#beepers
+#
+# FireBeelte v2 pinout:
+# https://image.dfrobot.com/image/data/DFR0654/pinout.png
+
+from machine import Pin
+from machine import PWM
+import time
+
+tones = {
+    'c': 262,  # https://muted.io/note-frequencies/
+    'd': 294,
+    'e': 330,
+    'f': 349,
+    'g': 392,
+    'a': 440,
+    'b': 494,
+    'C': 523,
+    ' ': 1,
+    }
+tempo = 3
+
+# Frequency can be from 1 Hz to 40 MHz
+# 10-bit duty range 0--1023 (default 512, 50%)
+beeper = PWM(Pin(17, Pin.OUT), freq=440, duty=512)
+
+melody = 'cde fgabC'
+rhythm = [8, 8, 8, 8, 8, 8, 8, 8, 8]
+
+# zip() is used to combine two iterables into "tone" and "length"
+for tone, length in zip(melody, rhythm):
+    print(f"Tone: {tone} \tDuration: {tempo/length}")
+    beeper.freq(tones[tone])
+    time.sleep(tempo/length)
+
+beeper.deinit()