# This work is licensed under the MIT license. # Copyright (c) 2013-2023 OpenMV LLC. All rights reserved. # https://github.com/openmv/openmv/blob/master/LICENSE # # MQTT Example. # This example shows how to use the MQTT library to subscribe to a topic. # # 1) Copy the mqtt.py library to OpenMV storage. # 2) Run this script on the OpenMV camera. # 3) Install the mosquitto client on PC and run the following command: # mosquitto_pub -t "openmv/test" -m "Hello World!" -h test.mosquitto.org -p 1883 # # NOTE: If the mosquitto broker is unreachable, try another broker (For example: broker.hivemq.com or broker.emqx.io) import time import network from mqtt import MQTTClient SSID = "" # Network SSID KEY = "" # Network key # Init wlan module and connect to network wlan = network.WLAN(network.STA_IF) wlan.active(True) wlan.connect(SSID, KEY) while not wlan.isconnected(): print('Trying to connect to "{:s}"...'.format(SSID)) time.sleep_ms(1000) # We should have a valid IP now via DHCP print("WiFi Connected ", wlan.ifconfig()) client = MQTTClient("openmv", "test.mosquitto.org", port=1883) client.connect() def callback(topic, msg): print(topic, msg) # must set callback first client.set_callback(callback) client.subscribe("openmv/test") while True: client.check_msg() # poll for messages. time.sleep_ms(1000)