树莓派mqtt通讯

一、sudo pip install paho-mqtt

二、python代码

# -*- coding: utf-8 -*- 
import paho.mqtt.client as mqtt
# import RPi.GPIO as GPIO
import json,sys

# if sys.version_info < (3, 0):
#     reload(sys)
#     sys.setdefaultencoding('utf8')
# else:
#     raw_input = input
username='public'
password='123456'
hostname='xxx.xxx.xxx.xxx'

# BCM GPIO编号
pins = [17,18,27,22,23,24,25,4]
def gpio_setup():
    # 采用BCM编号
    GPIO.setmode(GPIO.BCM)
    # 设置全部GPIO为输出状态，且输出低电平
    for pin in pins:
        GPIO.setup(pin, GPIO.OUT)
        GPIO.output(pin, GPIO.LOW)
       
def gpio_destroy():
    for pin in pins:
        GPIO.output(pin, GPIO.LOW)
        GPIO.setup(pin, GPIO.IN)
       
# 链接成功回调函数
def on_connect(client, userdata, flags, rc):
    print("Connected with result code " + str(rc))
    # 链接完成以后订阅gpio主题
    client.subscribe("gpio")

# 消息推送回调函数 .decode("utf-8")
def on_message(client, userdata, msg):

    print(msg.topic+""+str(msg.payload))
    #得到负载中的pin 和 value
    # gpio = json.loads(str(msg.payload))

    # if gpio['pin'] in pins:
    #     if gpio['value'] == 0:
    #         GPIO.output(gpio['pin'], GPIO.LOW)
    #     else:
    #         GPIO.output(gpio['pin'], GPIO.HIGH)

if __name__ == '__main__':
    client = mqtt.Client()
    client.on_connect = on_connect
    client.on_message = on_message
    # gpio_setup()
   
    try:
        # 请根据实际状况改变MQTT代理服务器的IP地址及帐户密码认证
        #client.username_pw_set(username,password)
        client.connect("xxx.xxx.xxx.xxx", 1883, 60)
        client.loop_forever()
    except KeyboardInterrupt:
        client.disconnect()
        gpio_destroy()

发送数据为{"pin":12,"value":1}