我是 Python 和 MQTT 的新手。我能够编写一些 Python 工作代码来将连接的传感器数据发布到代理,现在我想订阅多个主题并将所有有效负载写入连接到覆盆子的 LCD 20x4 上。
其实我写了一个Python来订阅一个topic,然后在LCD上写payload;没问题,它正在工作。无法在同一个 Python 中包含其他主题并在 LCD 上写入有效载荷。
您可以在下面找到“仅”一个主题的我的工作 Python 代码。
#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# RPi-S-LCD.py
# Created on 8/1/2017
#
# Python program that write payloads on LCD 20x4
#
import time
import sys
import os
import paho.mqtt.client as paho
sys.path.append("/home/pi/Adafruit_Python_CharLCD")
import Adafruit_CharLCD as LCD
import Adafruit_GPIO.MCP230xx as MCP
### Define MCP pins connected to LCD
lcd_rs = 6
lcd_en = 4
lcd_d4 = 3
lcd_d5 = 2
lcd_d6 = 1
lcd_d7 = 0
lcd_backlight = None
### Define LCD type
lcd_columns = 20
lcd_rows = 4
### Initialize MCP23017 for LCD
gpiomcp = MCP.MCP23017(0x20, busnum=1)
### Initialize LCD panel parameters
lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight, gpio=gpiomcp)
lcd.show_cursor(False)
lcd.blink(False)
lcd.clear()
### Read data from MQTT broker
def on_subscribe(client, userdata, mid, granted_qos):
print("Subscribed to the broker "+str(mid)+" "+str(granted_qos))
### Print topic data to LCD
def on_message1(client, userdata, msg):
lcd.set_cursor(0,0)
lcd.message(msg.payload)
client = paho.Client()
client.on_subscribe = on_subscribe
client.on_message = on_message1
client.connect("10.0.2.10", 1883, 30)
client.subscribe("iDomus/Time",2)
client.loop_forever()
最佳答案
阅读更多关于 MQTT 的文档我找到了这个函数
"message_callback_add"
现在 python 程序运行良好。这就是我的想法。 现在我订阅了所有主题,但我选择了我想要处理的特定主题,有效负载被分开以便在 LCD 上轻松可视化。 对不起我的 python 代码..我不是程序员,但下面它对我来说工作正常。希望它能帮助其他人解决我同样的问题。
#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# RPi-S-LCD.py
# Created on 21/1/2017
#
# Python program that use LCD 20x4 to display topics info
#
import time
import sys
import os
import paho.mqtt.client as paho
sys.path.append("/home/pi/Adafruit_Python_CharLCD")
import Adafruit_CharLCD as LCD
import Adafruit_GPIO.MCP230xx as MCP
### Define MCP pins connected to LCD
lcd_rs = 6
lcd_en = 4
lcd_d4 = 3
lcd_d5 = 2
lcd_d6 = 1
lcd_d7 = 0
lcd_backlight = None
### Define LCD type
lcd_columns = 20
lcd_rows = 4
### Initialize MCP23017 for LCD
gpiomcp = MCP.MCP23017(0x20, busnum=1)
### Initialize LCD panel parameters
lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight, gpio=gpiomcp)
lcd.show_cursor(False)
lcd.blink(False)
lcd.clear()
### DATE
def on_message_date(mosq, obj, msg):
lcd.set_cursor(0,0)
lcd.message(str(msg.payload))
### TIME
def on_message_time(mosq, obj, msg):
lcd.set_cursor(0,2)
lcd.message(str(msg.payload))
### RELAY
def on_message_relay(mosq, obj, msg):
if (str(msg.payload)[3]) == '0':
lcd.set_cursor(7,2)
lcd.message("RL1= 0 RL2= 0")
elif (str(msg.payload)[3]) == '1':
lcd.set_cursor(7,2)
lcd.message("RL1= 1 RL2= 0")
elif (str(msg.payload)[3]) == '2':
lcd.set_cursor(7,2)
lcd.message("RL1= 0 RL2= 1")
elif (str(msg.payload)[3]) == '3':
lcd.set_cursor(7,2)
lcd.message("RL1= 1 RL2= 1")
else:
lcd.set_cursor(7,2)
lcd.message("RELAYs ERROR!")
### PUBLIC IP
def on_message_pubip(mosq, obj, msg):
lcd.set_cursor(0,1)
lcd.message(" ")
lcd.set_cursor(0,1)
lcd.message("IP = "+str(msg.payload)[0:14])
### TEMPERATURE
def on_message_temp(mosq, obj, msg):
lcd.set_cursor(0,3)
lcd.message(str(msg.payload)[0:4]+chr(223)+"C")
### HUMIDITY
def on_message_humi(mosq, obj, msg):
lcd.set_cursor(7,3)
lcd.message(str(msg.payload)[0:4]+chr(37))
### PRESSURE
def on_message_pres(mosq, obj, msg):
lcd.set_cursor(13,3)
lcd.message(str(msg.payload)+"hPa")
### topic message
def on_message(mosq, obj, msg):
print(msg.topic+" "+str(msg.qos)+" "+str(msg.payload))
mqttc = paho.Client()
#Add message callbacks that will only trigger on a specific subscription match
mqttc.message_callback_add('iDomus/Time', on_message_time)
mqttc.message_callback_add('iDomus/Date', on_message_date)
mqttc.message_callback_add('iDomus/PubIPRead', on_message_pubip)
mqttc.message_callback_add('iDomus/RPiS/Sens1/Temp', on_message_temp)
mqttc.message_callback_add('iDomus/RPiS/Sens1/Humi', on_message_humi)
mqttc.message_callback_add('iDomus/RPiN/Sens2/Pres', on_message_pres)
mqttc.message_callback_add('iDomus/RPiS/Rel1/Read', on_message_relay)
mqttc.on_message = on_message
mqttc.connect("10.0.2.10", 1883, 30)
mqttc.subscribe("iDomus/#")
mqttc.loop_forever()
关于python - MQTT/Python订阅多个主题并在Raspberry LCD上写入payload,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41624697/