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()

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