Adds an lcd 16x2 example that also uses buzzer and buttons

pingo/examples/lcd16x2_countdown.py

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+""" A countdown in a 16x2 LCD.
+It is possible to pause or reset the countdown using buttons.
+When the countdown ends buzzes continuously.
+
+Requires:
+- Adafruit_CharLCD (https://github.com/adafruit/Adafruit_Python_CharLCD)
+
+Hardware:
+- 16x2 LCD (8 digital pins)
+- Buzzer (1 digital pin)
+- 2x buttons (1 digital pin each)
+
+"""
+
+
+import time
+import pingo
+
+import Adafruit_CharLCD.Adafruit_CharLCD as LCD
+
+
+lcd, buzzer, pause, pause_status, reset, countdown, COUNTDOWN = (None,) * 7
+
+
+def startup():
+    global lcd, buzzer, pause, pause_status, reset, countdown, COUNTDOWN
+
+    # LCD pins
+    lcd_rs = 18
+    lcd_en = 27
+    lcd_d4, lcd_d5, lcd_d6, lcd_d7 = 22, 23, 24, 25
+
+    # LCD config
+    lcd_backlight = 4
+    lcd_columns = 16
+    lcd_rows = 2
+
+    lcd = LCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns,
+              lcd_rows, lcd_backlight)
+
+    board = pingo.detect.get_board()
+
+    # buzzer pin (BOARD)
+    buzzer = board.pins[33]
+    buzzer.mode = pingo.OUT
+
+    # pause and reset buttons (BOARD)
+    pause = board.pins[29]
+    pause.mode = pingo.IN
+    reset = board.pins[31]
+    reset.mode = pingo.IN
+
+    COUNTDOWN = 300
+    pause_status = False
+    countdown = COUNTDOWN
+
+
+def beep(interval=0.06, times=4):
+    for _ in range(times):
+        buzzer.hi()
+        time.sleep(interval)
+        buzzer.lo()
+        time.sleep(interval)
+
+
+def seconds_to_minutes(seconds):
+    minutes = str(countdown / 60).zfill(2)
+    seconds = str(countdown % 60).zfill(2)
+    return '{} min {} seg'.format(minutes, seconds)
+
+
+def reset_countdown(delay_seconds=3):
+    beep(interval=0.03, times=3)
+    for seconds in reversed(range(1, delay_seconds + 1)):
+        lcd.clear()
+        lcd.message(u'RESETANDO...\n{} sec'.format(seconds))
+        time.sleep(1)
+    global countdown
+    countdown = COUNTDOWN
+    lcd.clear()
+
+
+if __name__ == "__main__":
+    startup()
+    while True:
+        lcd.clear()
+
+        if pause.state == pingo.HIGH:
+            pause_status = not pause_status
+            lcd.clear()
+            beep(interval=0.03, times=2)
+
+        if pause_status:
+            lcd.message(u'PAUSADO em\n{}'.format(seconds_to_minutes(countdown)))
+            time.sleep(2.5)
+            continue
+
+        if reset.state == pingo.HIGH:
+            reset_countdown(3)
+
+        if countdown == 0:
+            lcd.message(u'Acabou! Acabou!\nO turno acabou!')
+            beep()
+            time.sleep(0.999)
+            continue
+
+        lcd.message(u'Turno acaba em:\n{}'.format(seconds_to_minutes(countdown)))
+
+        time.sleep(0.999)
+        countdown -= 1