python定时获取树莓派硬件参数并使用MQTT进行数据推送

树莓派python安装mqtt库

pip3 install paho-mqtt

定时获取树莓派温度、CPU、内存、硬盘信息，使用公共服务器broker.emqx.io进行数据推送，上代码

import os
import random
import time
import json
from paho.mqtt import client as mqtt_client

broker = 'broker.emqx.io'
port = 1883
topic = "/python/mqtt"
# generate client ID with pub prefix randomly
client_id = f'python-mqtt-{random.randint(0, 1000)}'
# Return CPU temperature as a character string                                      
def getCPUtemperature():
    res = os.popen('vcgencmd measure_temp').readline()
    return(res.replace("temp=","").replace("'C\n",""))
 
# Return RAM information (unit=kb) in a list                                       
# Index 0: total RAM                                                               
# Index 1: used RAM                                                                 
# Index 2: free RAM                                                                 
def getRAMinfo():
    p = os.popen('free')
    i = 0
    while 1:
        i = i + 1
        line = p.readline()
        if i==2:
            return(line.split()[1:4])
 
# Return % of CPU used by user as a character string                                
def getCPUuse():
    return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip()))
 
# Return information about disk space as a list (unit included)                     
# Index 0: total disk space                                                         
# Index 1: used disk space                                                         
# Index 2: remaining disk space                                                     
# Index 3: percentage of disk used                                                  
def getDiskSpace():
    p = os.popen("df -h /")
    i = 0
    while 1:
        i = i +1
        line = p.readline()
        if i==2:
            return(line.split()[1:5])

def connect_mqtt():
    def on_connect(client, userdata, flags, rc):
        if rc == 0:
            print("Connected to MQTT Broker!")
        else:
            print("Failed to connect, return code %d\n", rc)

    client = mqtt_client.Client(client_id)
    client.on_connect = on_connect
    client.connect(broker, port)
    return client


def publish(client):
    # CPU informatiom
    CPU_temp = getCPUtemperature()
    CPU_usage = getCPUuse()
     
    # RAM information
    # Output is in kb, here I convert it in Mb for readability
    RAM_stats = getRAMinfo()
    RAM_total = round(int(RAM_stats[0]) / 1000,1)
    RAM_used = round(int(RAM_stats[1]) / 1000,1)
    RAM_free = round(int(RAM_stats[2]) / 1000,1)
     
    # Disk information
    DISK_stats = getDiskSpace()
    DISK_total = DISK_stats[0]
    DISK_used = DISK_stats[1]
    result = client.publish(topic, json.dumps({"CPU Temperature":CPU_temp,"CPU Use":CPU_usage,"RAM Total":str(RAM_total)+' MB',"RAM Used":str(RAM_used)+' MB',"RAM Free":str(RAM_free)+' MB',"DISK Total":str(DISK_total)+'B',"DISK Used":str(DISK_used)+'B'}))
    status = result[0]
    if status == 0:
        print(f"Send msg to topic `{topic}`")
    else:
        print(f"Failed to send message to topic {topic}")


def run():
    client = connect_mqtt()
    publish(client)

if __name__ == '__main__':
    run()

在线测试工具：http://tools.emqx.io/

点击connect连接服务器。

点击New Subscription，topic输入代码第九行定义的topic主题名称，也就是“/python/mqtt”