例程讲解14-WiFi-Shield->mqtt

# MQTT 示例
# 此示例显示如何使用MQTT库。
# 1) 将mqtt.py库复制到OpenMV内存。
# 2) 在PC上安装mosquitto客户端并运行以下命令：
#    mosquitto_sub -h test.mosquitto.org -t "openmv/test" -v
#
import time, network
from mqtt import MQTTClient

SSID='' # Network SSID
KEY=''  # Network key

# 初始化wlan模块并连接到网络
print("Trying to connect... (may take a while)...")

wlan = network.WINC()
wlan.connect(SSID, key=KEY, security=wlan.WPA_PSK)

# 我们现在应该通过DHCP获得有效的IP
print(wlan.ifconfig())

client = MQTTClient("openmv", "test.mosquitto.org", port=1883)
client.connect()

while (True):
    client.publish("openmv/test", "Hello World!")
    time.sleep_ms(1000)