Programming with MicroPython: WiFi & IoT

Import FutureBoard Library

Import the Library to make use of its functions.

from future import *

07: WiFi & IoT

1. Connect to WiFi

wifi.connect('router','password')

FutureBoard can only connect to wireless networks with 2.4GHz frequency.

2. Get the Connection Status

wifi.sta.isconnected()

Returns 1 if FutureBoard is connected to the network, 0 if not.

3. Get the Connection Configuration

wifi.sta.ifconfig()

Returns a list with the configuration including IP Address, Subnet Mask, Gateway, Domain.

4. Get the MAC Address

import machine
import ubinascii

x = ubinascii.hexlify(machine.unique_id()).decode().upper()

Returns the physical address of the FutureBoard.

5. File Download

wifi.download("PASTE FILE LINK","FILE NAME")

Downloads a file from a file URL and saves it to the SD card.

Sample Program 1~4

#/bin/python
from future import *

from time import sleep

import machine
import ubinascii

wifi.connect(str("name"), "pwd")
sleep(5)
if wifi.sta.isconnected():
  screen.clear()
  screen.text(str("IP: ")+str(wifi.sta.ifconfig()[0]),5,10,1,(0, 119, 255))
  screen.text("MAC Address: ",5,25,1,(0, 119, 255))
  screen.text(ubinascii.hexlify(machine.unique_id()).decode().upper(),5,35,1,(0, 119, 255))
  screen.text("Subnet Mask: ",5,50,1,(0, 119, 255))
  screen.text(wifi.sta.ifconfig()[1],5,60,1,(0, 119, 255))
  screen.text(str("Gateway: ")+str(wifi.sta.ifconfig()[2]),5,75,1,(0, 119, 255))
  screen.text(str("DNS: ")+str(wifi.sta.ifconfig()[3]),5,90,1,(0, 119, 255))

Import MQTT Library

import mqttsimple

MQTT operations require the mqttsimple library.

5. Set up an MQTT object

myMQTT = mqttsimple.MQTTClient(server,client_id,port=0,user=None,password=None,keepalive=0,ssl=False,ssl_params={})

Creates an object with the connection to the MQTT Broker.

For most brokers, insert the host address into server and the client id into client_id.

For some brokers, please refer to the broker’s documentations for the details required to connect to the server.

6. Connect to the MQTT Server

myMQTT.connect()

7. Disconnect the MQTT Server

myMQTT.disconnect()

8. Subscribe to a MQTT Topic

myMQTT.subscribe(topic=)

Fill in the topic name according to the documentation of the MQTT Broker.

9. Publish a Message to a MQTT Topic

myMQTT.publish(topic,msg)

Fill in the message and topic name according to the documentation of the MQTT Broker.

10. Read the Message from the MQTT Topic

myMQTT.read(topic)

Fill in the topic name according to the documentation of the MQTT Broker.

11. Read the Last Message of the MQTT Topic

myMQTT.check_msg()

12. Wait until a MQTT Message is Published

myMQTT.wait_msg()

13. Define MQTT Event Trigger Function

def myFunction(topic,msg):
    print(topic)
    print(msg)

myMQTT.set_callback(myFunction())

Sample Program 1

import mqttsimple
if not(wifi.sta.isconnected()):
    wifi.connect('router', 'password') 

c = mqttsimple.MQTTClient("myServer", 'myID')
c.connect() 

c.subscribe('/topic1')

x= 0
# mqttRead() returns None if no new message is found
while 1:
    if sensor.btnValue('a'):
        x+=1
        c.publish('/topic1','x'+str(x))
        sleep(0.2)
    # Print message if message is not None
    mqttT = c.read('/topic1')
    if mqttT:
        print(mqttT)

Sample Program 2

import mqttsimple
if not(wifi.sta.isconnected()):
    wifi.connect('router', 'password') 

c = mqttsimple.MQTTClient("myServer", 'myID')
c.connect() 

# Automacically triggered when topic is updated
def sub_cb(topic, msg):
    print((topic, msg))   
c.set_callback(sub_cb)
    
c.subscribe('/ttt')

while 1:
    if sensor.btnValue('a'):
        c.publish('/ttt', 'hello')
        sleep(0.2)
    # check message
    c.check_msg()

# try below for waiting until message update
# c.wait_msg()

urequests and ujson Libraries

urequests and ujson libraries are also available to use. Please visit their official documentation for details.

urequests API documentation

ujson API Documentation

Import urequests and ujson Libraries

import urequests
import json