• ESP-32: The ESP32 makes it easy to use the Arduino IDE and the Arduino Wire Language for IoT applications. This ESP32 IoT Module combines Wi-Fi, Bluetooth, and Bluetooth BLE for a variety of diverse applications. This module comes fully-equipped with 2 CPU cores that can be controlled and powered individually, and with an adjustable clock frequency of 80 MHz to 240 MHz. This ESP32 IoT WiFi BLE Module with Integrated USB is designed to fit in all IoT products. Monitor sensors and control relays, FETs, PWM controllers, solenoids, valves, motors and much more from anywhere in the world using a web page or a dedicated server. We manufactured our own version of the ESP32 to fit into NCD IoT devices, offering more expansion options than any other device in the world! An integrated USB port allows easy programming of the ESP32. The ESP32 IoT WiFi BLE Module is an incredible platform for IoT application development. This ESP32 IoT WiFi BLE Module can be programmed using the Arduino IDE.
  • IoT Long Range Wireless Temperature and Humidity Sensor:Industrial Long Range Wireless Temperature Humidity Sensor. Grade with a Sensor Resolution of ±1.7%RH ±0.5°C. Up to 500, 000 Transmissions from 2 AA Batteries. Measures -40°C to 125°C with Batteries that Survive these Ratings.Superior 2-Mile LOS Range & 28 miles with High-Gain Antennas.Interface to Raspberry Pi, Microsoft Azure, Arduino and More
  • Long-Range Wireless Mesh Modem with USB Interface

Software Used

  • Arduino IDE
  • ThingSpeak

Library Used

  • PubSubClient Library
  • Wire.h

Arduino Client for MQTT

This library provides a client for doing simple publish/subscribe messaging with a server that supports MQTT

For more information about MQTT, visit


The latest version of the library can be downloaded from GitHub


The library comes with a number of example sketches. See File > Examples > PubSubClient within the Arduino application. Full API Documentation.

Compatible Hardware

The library uses the Arduino Ethernet Client API for interacting with the underlying network hardware. This means it Just Works with a growing number of boards and shields, including:

  • Arduino Ethernet
  • Arduino Ethernet Shield
  • Arduino YUN – use the included YunClient in place of EthernetClient, and be sure to do a Bridge.begin() first
  • Arduino WiFi Shield - if you want to send packets greater than 90 bytes with this shield, enable the MQTT_MAX_TRANSFER_SIZE option in PubSubClient.h.
  • Sparkfun WiFly Shield – when used with this library
  • Intel Galileo/Edison
  • ESP8266
  • ESP32The library cannot currently be used with hardware based on the ENC28J60 chip – such as the Nanode or the Nuelectronics Ethernet Shield. For those, there is an alternative library available.

Wire Library

The Wire library allows you to communicate with I2C devices, often also called “2 wire” or “TWI” (Two Wire Interface), can download from Wire.h

Basic Usage

  • Wire.begin()Begin using Wire in master mode, where you will initiate and control data transfers. This is the most common use when interfacing with most I2C peripheral chips.
  • Wire.begin(address)Begin using Wire in slave mode, where you will respond at “address” when other I2C masters chips initiate communication.


  • Wire.beginTransmission(address)Start a new transmission to a device at “address”. Master mode is used.
  • Wire.write(data)Send data. In master mode, beginTransmission must be called first.
  • Wire.endTransmission()In master mode, this ends the transmission and causes all buffered data to be sent.


  • Wire.requestFrom(address, count)Read “count” bytes from a device at “address”. Master mode is used.
  • Wire.available()Returns the number of bytes available by calling receive.
  • 1 byte.

Uploading the Code to ESP32 using Arduino IDE

  • Before uploading the code you can view the working of this...
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