Use propper midi to hertz formula

stechuhr_client/client.py

@@ -181,34 +181,37 @@ def dispatch_buzzer(state, config):
 
 def set_buzzer(state, config):
     global buzzer_pin
-    f = 8.175799
     buzzer = GPIO.PWM(buzzer_pin, f) # Set frequency to 1 Khz
 
     state = str(state).strip().lower()
     if state in ["startup", "ready"]:
         buzzer = GPIO.PWM(buzzer_pin, f) # Set frequency to 1 Khz
         for i, note in enumerate(config["buzzer"]["startup_notes"]):
-            buzzer.ChangeFrequency((1+note)*0.083333333*f)  # Set frequency to 1 Khz
+            buzzer.ChangeFrequency(midinumber_to_hertz(note))  # Set frequency to 1 Khz
             buzzer.start(50) # Set dutycycle to 10
             time.sleep(repeat(config["buzzer"]["startup_note_lengths"], i))
             buzzer.stop()
             time.sleep(repeat(config["buzzer"]["startup_note_stop_lengths"], i))
     elif state in ["success"]:
         for i, note in enumerate(config["buzzer"]["success_notes"]):
-            buzzer.ChangeFrequency((1+note)*0.083333333*f)  # Set frequency to 1 Khz
+            buzzer.ChangeFrequency(midinumber_to_hertz(note))  # Set frequency to 1 Khz
             buzzer.start(50) # Set dutycycle to 10
             time.sleep(repeat(config["buzzer"]["success_note_lengths"], i))
             buzzer.stop()
             time.sleep(repeat(config["buzzer"]["success_note_stop_lengths"], i))
     elif state in ["failure"]:
         for i, note in enumerate(config["buzzer"]["failure_notes"]):
-            buzzer.ChangeFrequency((1+note)*0.083333333*f)  # Set frequency to 1 Khz
+            buzzer.ChangeFrequency(midinumber_to_hertz(note))  # Set frequency to 1 Khz
             buzzer.start(50) # Set dutycycle to 10
             time.sleep(repeat(config["buzzer"]["failure_note_lengths"], i))
             buzzer.stop()
             time.sleep(repeat(config["buzzer"]["failure_note_stop_lengths"], i))
 
 
+def midinumber_to_hertz(number) -> float:
+    return 440 * 2**(number-69)/12
+
+
 def process_request(output_queue, config=None, logger=None):
     """
     Process a event from the output queue.