Adding example for AIO Basics: Servo

Author: brentru

Adafruit_IO/_version.py

@@ -0,0 +1,72 @@
+"""
+`servo.py`
+------------------
+Control a servo
+with Adafruit IO
+
+Requires:
+    - Adafruit-Blinka
+    - Adafruit-CircuitPython-PCA9685
+    - Adafruit-CircuitPython-Motor
+"""
+# import system libraries
+import time
+
+# import Adafruit Blinka
+from board import SCL, SDA
+from busio import I2C
+
+# import the PCA9685 module.
+from adafruit_pca9685 import PCA9685
+
+# import the adafruit_motor library
+from adafruit_motor import servo
+
+# import Adafruit IO REST client
+from Adafruit_IO import Client, Feed, RequestError
+
+# Set to your Adafruit IO username.
+# (go to https://accounts.adafruit.com to find your username)
+ADAFRUIT_IO_USERNAME = 'YOUR_AIO_USERNAME'
+
+# Set to your Adafruit IO key.
+# Remember, your key is a secret,
+# so make sure not to publish it when you publish this code!
+ADAFRUIT_IO_KEY = 'YOUR_AIO_KEY'
+
+# Create an instance of the REST client.
+aio = Client(ADAFRUIT_IO_USERNAME, ADAFRUIT_IO_KEY)
+
+try: # if we have a 'servo' feed
+    servo_feed = aio.feeds('servo')
+except RequestError: # create a servo feed
+    feed = Feed(name='servo')
+    servo_feed = aio.create_feed(feed)
+
+# Create the I2C bus interface.
+i2c_bus = I2C(SCL, SDA)
+
+# Create a simple PCA9685 class instance.
+pca = PCA9685(i2c_bus)
+
+# Set the PWM frequency to 50hz.
+pca.frequency = 50
+SERVO_CHANNEL = 0
+
+# counter variable for the last servo angle
+prev_angle = 0
+
+# set up the servo on PCA channel 0
+my_servo = servo.Servo(pca.channels[SERVO_CHANNEL])
+
+
+while True:
+    # grab the `servo` feed value
+    servo_angle = aio.receive(servo_feed.key)
+    if servo_angle.value != prev_angle:
+        print('received <- ', servo_angle.value, 'Degrees')
+        # write the servo to the feed-specified angle
+        my_servo.angle = int(servo_angle.value)
+    prev_angle = servo_angle.value
+    # timeout so we don't flood IO with requests
+    time.sleep(0.5)