add adafruitio_ethernet mmqt example

Author: brentru

examples/minimqtt_adafruitio_eth.py

@@ -0,0 +1,87 @@
+# Adafruit MiniMQTT Pub/Sub Example
+# Written by Tony DiCola for Adafruit Industries
+# Modified by Brent Rubell for Adafruit Industries
+import time
+import board
+import busio
+from digitalio import DigitalInOut
+
+from adafruit_wiznet5k.adafruit_wiznet5k import WIZNET5K
+import adafruit_wiznet5k.adafruit_wiznet5k_socket as socket
+
+import adafruit_minimqtt as MQTT
+
+# Get Adafruit IO details and more from a secrets.py file
+try:
+    from secrets import secrets
+except ImportError:
+    print("Adafruit IO secrets are kept in secrets.py, please add them there!")
+    raise
+
+cs = DigitalInOut(board.D10)
+spi_bus = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
+
+# Initialize ethernet interface with DHCP
+eth = WIZNET5K(spi_bus, cs)
+
+### Feeds ###
+
+# Setup a feed named 'photocell' for publishing to a feed
+photocell_feed = secrets['aio_username'] + '/feeds/photocell'
+
+# Setup a feed named 'onoff' for subscribing to changes
+onoff_feed = secrets['aio_username'] + '/feeds/onoff'
+
+### Code ###
+
+# Define callback methods which are called when events occur
+# pylint: disable=unused-argument, redefined-outer-name
+def connected(client, userdata, flags, rc):
+    # This function will be called when the client is connected
+    # successfully to the broker.
+    print('Connected to Adafruit IO! Listening for topic changes on %s' % onoff_feed)
+    # Subscribe to all changes on the onoff_feed.
+    client.subscribe(onoff_feed)
+
+
+def disconnected(client, userdata, rc):
+    # This method is called when the client is disconnected
+    print('Disconnected from Adafruit IO!')
+
+
+def message(client, topic, message):
+    # This method is called when a topic the client is subscribed to
+    # has a new message.
+    print('New message on topic {0}: {1}'.format(topic, message))
+
+
+# Initialize MQTT interface with the ethernet interface
+MQTT.set_socket(socket, eth)
+
+# Set up a MiniMQTT Client
+# NOTE: We'll need to connect insecurely for ethernet configurations.
+mqtt_client = MQTT.MQTT(broker = 'io.adafruit.com',
+                        username = secrets['aio_username'],
+                        password = secrets['aio_key'],
+                        is_ssl = False)
+
+# Setup the callback methods above
+mqtt_client.on_connect = connected
+mqtt_client.on_disconnect = disconnected
+mqtt_client.on_message = message
+
+# Connect the client to the MQTT broker.
+print('Connecting to Adafruit IO...')
+mqtt_client.connect()
+
+photocell_val = 0
+while True:
+    # Poll the message queue
+    mqtt_client.loop()
+
+    # Send a new message
+    print('Sending photocell value: %d...' % photocell_val)
+    mqtt_client.publish(photocell_feed, photocell_val)
+    print('Sent!')
+    photocell_val += 1
+    time.sleep(5)