Main.py file for Implementing an end-to-end IoT Solution in MongoDB. Used with NodeMCU and MicroPython

main.py

from umqtt.simple import MQTTClient
import network
import machine
import time
import socket
import utime

ssid=#Put your SSID name here
pwd=#Put your WiFi password here
device_name='TempSensor1' #Put the name of the device here
mqqt_server=#Put the IP address of your MQTT
mqqt_port=1883  #Change if needed, default port for MQQT

# **** Set variables and define functions that support grabbing current time from an NTP server
# borrowed from https://github.com/micropython/micropython/blob/master/ports/esp8266/modules/ntptime.py
# (date(2000, 1, 1) - date(1900, 1, 1)).days * 24*60*60
NTP_DELTA = 3155673600
host="pool.ntp.org"

try:
    import usocket as socket
except:
    import socket
try:
    import ustruct as struct
except:
    import struct

def time():
    NTP_QUERY = bytearray(48)
    NTP_QUERY[0] = 0x1b
    addr = socket.getaddrinfo(host, 123)[0][-1]
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.settimeout(1)
    res = s.sendto(NTP_QUERY, addr)
    msg = s.recv(48)
    s.close()
    val = struct.unpack("!I", msg[40:44])[0]
    return val - NTP_DELTA

def settime():
    t = time()
    import machine
    import utime
    tm = utime.localtime(t)
    tm = tm[0:3] + (0,) + tm[3:6] + (0,)
    machine.RTC().datetime(tm)

def do_connect():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('connecting to ' + ssid)
        wlan.connect(ssid, pwd)
        while not wlan.isconnected():
            pass
    print('network config:', wlan.ifconfig())
    settime()
    print('current time=%s' % (machine.RTC().datetime(),))
    
def start_sampling():   
    client = MQTTClient(device_name, mqqt_server,mqqt_port)
    client.connect()
    adc = machine.ADC(0)
    i=adc.read()
    c=(i/10)
    f = (c * (9/5)) + 32
    #Note: message contents are the value in F and time in unix timestamp
    d=machine.RTC().datetime()
    s='{ "device":"' + str(device_name) + '","value": ' + str(f) + ', "time":"' + str(d)  + '"}'
    client.publish('/iotdemo/temp',s)
    client.disconnect()

def set_led(v):
    led = machine.Pin(5, machine.Pin.OUT)
    if v==1:
        led.on()
    else:
        led.off()             

do_connect()

while True:
    set_led(1)
    start_sampling()
    set_led(0)
    utime.sleep(5)