Adding candy claw code

Adding code for the BLE Candy Claw learn guide. Uses a CPB with a servo and the Bluefruit connect app. Buttons in the app open and close the servo-powered claw.

Author: BlitzCityDIY

BLE_Candy_Claw/code.py

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+import time
+import board
+import pulseio
+from adafruit_motor import servo
+from adafruit_bluefruit_connect.packet import Packet
+from adafruit_bluefruit_connect.button_packet import ButtonPacket
+from adafruit_ble import BLERadio
+from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
+from adafruit_ble.services.nordic import UARTService
+
+ble = BLERadio()
+uart = UARTService()
+advertisement = ProvideServicesAdvertisement(uart)
+
+pwm = pulseio.PWMOut(board.A3, duty_cycle=2 ** 15, frequency=50)
+
+my_servo = servo.Servo(pwm)
+
+while True:
+    print("WAITING...")
+    # Advertise when not connected.
+    ble.start_advertising(advertisement)
+    while not ble.connected:
+        pass
+
+    # Connected
+    ble.stop_advertising()
+    print("CONNECTED")
+
+    # Loop and read packets
+    while ble.connected:
+        if uart.in_waiting:
+            packet = Packet.from_stream(uart)
+            if isinstance(packet, ButtonPacket):
+                #  if buttons in the app are pressed
+                if packet.pressed:
+                    if packet.button == ButtonPacket.DOWN:
+                        print("pressed down")
+                        for angle in range(90, 170, 90):  # 90 - 170 degrees, 90 degrees at a time.
+                            my_servo.angle = angle
+                            time.sleep(0.05)
+                    if packet.button == ButtonPacket.UP:
+                        print("pressed up")
+                        for angle in range(170, 90, -90): # 170 - 90 degrees, 9 degrees at a time.
+                            my_servo.angle = angle
+                            time.sleep(0.05)
+    # Disconnected
+    print("DISCONNECTED")