main_shadowEcho.py

from MQTTLib import AWSIoTMQTTShadowClient
from network import WLAN
import time
import config
import json

# Connect to wifi
wlan = WLAN(mode=WLAN.STA)
wlan.connect(config.WIFI_SSID, auth=(None, config.WIFI_PASS), timeout=5000)
while not wlan.isconnected():
    time.sleep(0.5)
print('WLAN connection succeeded!')

# Custom Shadow callback with echo
class shadowCallbackContainer:
	def __init__(self, deviceShadowInstance):
		self.deviceShadowInstance = deviceShadowInstance

	# Custom Shadow callback
	def customShadowCallback_Delta(self, payload, responseStatus, token):
		print("Received a delta message:")
		payloadDict = json.loads(payload)
		deltaMessage = json.dumps(payloadDict["state"])
		print(deltaMessage)
		print("Request to update the reported state...")
		newPayload = '{"state":{"reported":' + deltaMessage + '}}'
		self.deviceShadowInstance.shadowUpdate(newPayload, None, 5)
		print("Sent.")

# configure the MQTT client
pycomAwsMQTTShadowClient = AWSIoTMQTTShadowClient(config.CLIENT_ID)
pycomAwsMQTTShadowClient.configureEndpoint(config.AWS_HOST, config.AWS_PORT)
pycomAwsMQTTShadowClient.configureCredentials(config.AWS_ROOT_CA, config.AWS_PRIVATE_KEY, config.AWS_CLIENT_CERT)

pycomAwsMQTTShadowClient.configureConnectDisconnectTimeout(config.CONN_DISCONN_TIMEOUT)
pycomAwsMQTTShadowClient.configureMQTTOperationTimeout(config.MQTT_OPER_TIMEOUT)

# Connect to MQTT Host
if pycomAwsMQTTShadowClient.connect():
    print('AWS connection succeeded')

deviceShadowHandler = pycomAwsMQTTShadowClient.createShadowHandlerWithName(config.THING_NAME, True)

shadowCallbackContainer_Bot = shadowCallbackContainer(deviceShadowHandler)
deviceShadowHandler.shadowRegisterDeltaCallback(shadowCallbackContainer_Bot.customShadowCallback_Delta)

# Loop forever
while True:
	time.sleep(1)