Examples¶
The following are a list of examples for lib.zerynth.mqtt.
MQTT at mosquitto.org¶
This simple example shows how to connect to an mqtt broker using Zerynth mqtt module and how to start publishing data on a channel and receiving data from other sources publishing on different ones.
main.py
################################################################################
# MQTT at mosquitto.org
#
# Created: 2015-10-15 21:37:25.886276
#
################################################################################
import streams
from mqtt import mqtt
from wireless import wifi
# the wifi module needs a networking driver to be loaded
# in order to control the device hardware.
# FOR THIS EXAMPLE TO WORK, A NETWORK DRIVER MUST BE SELECTED BELOW
# uncomment one of the following lines depending on used board
# (e.g. Particle Photon, esp8266 based board, esp32 based board)
# from broadcom.bcm43362 import bcm43362 as wifi_driver
# from espressif.esp32net import esp32wifi as wifi_driver
# from espressif.esp8266wifi import esp8266wifi as wifi_driver
# init the wifi driver!
# The driver automatically registers itself to the wifi interface
# with the correct configuration for the selected device
wifi_driver.auto_init()
streams.serial()
# use the wifi interface to link to the Access Point
# change network name, security and password as needed
print("Establishing Link...")
try:
# FOR THIS EXAMPLE TO WORK, "Network-Name" AND "Wifi-Password" MUST BE SET
# TO MATCH YOUR ACTUAL NETWORK CONFIGURATION
wifi.link("Network-Name",wifi.WIFI_WPA2,"Wifi-Password")
except Exception as e:
print("ooops, something wrong while linking :(", e)
while True:
sleep(1000)
# define MQTT callbacks
def is_sample(data):
if ('message' in data):
return (data['message'].qos == 1 and data['message'].topic == "desktop/samples")
return False
def print_sample(client,data):
message = data['message']
print("sample received: ", message.payload)
def print_other(client,data):
message = data['message']
print("topic: ", message.topic)
print("payload received: ", message.payload)
def send_sample(obj):
print("publishing: ", obj)
client.publish("temp/random", str(obj))
def publish_to_self():
client.publish("desktop/samples","hello! "+str(random(0,10)))
try:
# set the mqtt id to "zerynth-mqtt"
client = mqtt.Client("zerynth-mqtt",True)
# and try to connect to "test.mosquitto.org"
for retry in range(10):
try:
client.connect("test.mosquitto.org", 60)
break
except Exception as e:
print("connecting...")
print("connected.")
# subscribe to channels
client.subscribe([["desktop/samples",1]])
client.subscribe([["desktop/others",2]])
# configure callbacks for "PUBLISH" message
client.on(mqtt.PUBLISH,print_sample,is_sample)
# start the mqtt loop
client.loop(print_other)
# Every 3 seconds, send a random number to "temp/random"
# you can check temp/random changing here: http://test.mosquitto.org/gauge/
while True:
sleep(3000)
x = random(0,50)
send_sample(x)
# when x ends with 0, publish a message to desktop/samples
# it is echoed back
if x%10==0:
publish_to_self()
except Exception as e:
print(e)