docs: add native networking example

Author: zbauman3

examples/aws_iot_native_networking.py

@@ -0,0 +1,123 @@
+# SPDX-FileCopyrightText: 2023 ladyada for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+import time
+import ssl
+import socketpool
+import wifi
+import json
+import adafruit_minimqtt.adafruit_minimqtt as MQTT
+from adafruit_aws_iot import MQTT_CLIENT
+
+# Add a secrets.py to your filesystem that has a dictionary called "secrets". DO NOT share that
+# file or commit it into Git or other source control. The "secrets" dictionary should have the
+# following keys:
+# "ssid" - Your WiFi ssid
+# "password" - Your WiFi password
+# "device_cert_path" - Path to the Device Certificate from AWS IoT ("<THING_NAME>.cert.pem")
+# "device_key_path" - Path to the RSA Private Key from AWS IoT ("<THING_NAME>.private.key")
+# "broker" - The endpoint for the AWS IoT broker ("<PREFIX>.iot.<REGION>.amazonaws.com")
+# "port" - The port for the "broker" above (8883)
+# "client_id" - The client id. Your device's Policy needs to allow this client ("basicPubSub")
+#
+# pylint: disable=no-name-in-module,wrong-import-order
+try:
+    from secrets import secrets
+except ImportError:
+    print("WiFi secrets are kept in secrets.py, please add them there!")
+    raise
+
+### Code ###
+
+# Your device's Policy needs to allow this topic
+topic = "sdk/test/python"
+
+# Define callback methods which are called when events occur
+# pylint: disable=unused-argument, redefined-outer-name
+def connect(client, userdata, flags, rc):
+    # This function will be called when the client is connected
+    # successfully to the broker.
+    print("Connected to MQTT Broker!")
+    print("Flags: {0} - RC: {1}".format(flags, rc))
+
+    # Subscribe to topic circuitpython/aws
+    print("Subscribing to topic {}".format(topic))
+    aws_iot.subscribe(topic)
+
+
+def disconnect(client, userdata, rc):
+    # This method is called when the client disconnects
+    # from the broker.
+    print("Disconnected from MQTT Broker!")
+
+
+def subscribe(client, userdata, topic, granted_qos):
+    # This method is called when the client subscribes to a new topic.
+    print("Subscribed to {0} with QOS level {1}".format(topic, granted_qos))
+
+    # Create a json-formatted message
+    message = {"message": "Hello from AWS IoT CircuitPython"}
+    # Publish message to topic
+    aws_iot.publish(topic, json.dumps(message))
+
+
+def unsubscribe(client, userdata, topic, pid):
+    # This method is called when the client unsubscribes from a topic.
+    print("Unsubscribed from {0} with PID {1}".format(topic, pid))
+
+
+def publish(client, userdata, topic, pid):
+    # This method is called when the client publishes data to a topic.
+    print("Published to {0} with PID {1}".format(topic, pid))
+
+
+def message(client, topic, msg):
+    # This method is called when the client receives data from a topic.
+    print("Message from {}: {}".format(topic, msg))
+
+
+print("Connecting to %s" % secrets["ssid"])
+wifi.radio.connect(secrets["ssid"], secrets["password"])
+print("Connected to %s!" % secrets["ssid"])
+
+# Create a socket pool
+pool = socketpool.SocketPool(wifi.radio)
+ssl_context = ssl.create_default_context()
+
+# Set AWS Device Certificate and AWS RSA Private Key
+ssl_context.load_cert_chain(
+    certfile=secrets['device_cert_path'],
+    keyfile=secrets['device_key_path']
+)
+
+# Set up a MiniMQTT Client
+mqtt_client = MQTT.MQTT(
+    broker=secrets["broker"],
+    port=secrets["port"],
+    is_ssl=True, # ssl is required
+    client_id=secrets["client_id"],
+    socket_pool=pool,
+    ssl_context=ssl_context,
+)
+
+# Initialize AWS IoT MQTT API Client
+aws_iot = MQTT_CLIENT(mqtt_client)
+
+# Connect callback handlers to AWS IoT MQTT Client
+aws_iot.on_connect = connect
+aws_iot.on_disconnect = disconnect
+aws_iot.on_subscribe = subscribe
+aws_iot.on_unsubscribe = unsubscribe
+aws_iot.on_publish = publish
+aws_iot.on_message = message
+
+print("Attempting to connect to %s" % mqtt_client.broker)
+aws_iot.connect()
+
+# Start a blocking message loop...
+# NOTE: NO code below this loop will execute
+# NOTE: Network reconnection is NOT handled within this loop
+while True:
+    aws_iot.loop()
+
+    time.sleep(1)