# IOT Protocols and Implementation - Development Board (4)

**URL:** <http://staging.stemaway.com/t/iot-protocols-and-implementation-development-board-4/243>\
**Category:** Technical Resources\
**Created:** [October 23, 2019, 6:41pm UTC](http://staging.stemaway.com/t/iot-protocols-and-implementation-development-board-4/243 "2019-10-23T18:41:04Z")\
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**Author:** ![aseemsethi](https://d3rzmptxz7fqzy.cloudfront.net/letter_avatar_proxy/v4/letter/a/c38d9e/32.png) [@aseemsethi](http://staging.stemaway.com/u/aseemsethi)\
**Post date:** [October 23, 2019, 6:41pm UTC](http://staging.stemaway.com/t/iot-protocols-and-implementation-development-board-4/243/1 "2019-10-23T18:41:04Z")

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# Choosing a Hardware Board

One can buy a hardware development board for testing and implementing a basic MQTT client. The board I used was purchased from Amazon at the following link:

> **[Blynk Internet of Things - IOT kit : Amazon.in: Industrial & Scientific](https://www.amazon.in/Robo-India-BLB-02-Internet-Things/dp/B01M1BXUV6)**
>
> This product will be an excellent pick for you. It comes in a proper packaging.

This is a NodeMCU Development board with a ESP8266-12-E SOC.

In the following sections, I will describe how I set this up to work with Arduino IDE and implemented some basic MQTT Client code, so that it connects to a local WiFi in your home, and to the [iot.eclipse.org](http://iot.eclipse.org) server, so that messages can then be received by the Android App that implements another side of the MQTT client.

# Working with the ESP8266 NodeMCU Amica Blynk Board

The ESP8266 processor from Espressif is an 80 MHz microcontroller with a full WiFi front-end (both as client and access point) and TCP/IP stack with DNS support as well. It has Integrated low power 32-bit CPU, and has a Standby power consumption of \< 1.0mW (DTIM3). ESP8266 consumes less than 12uA in sleep mode and less than 1.0mW (DTIM=3) or less than 0.5mW (DTIM=10) to stay connected to the access point. It has 16 GPIO pins (ESP-12-E has 22 pins).

Specification is available at [https://www.aerial.net/shop/PDF/ESP8266\_Specifications\_English.pdf](https://www.aerial.net/shop/PDF/ESP8266_Specifications_English.pdf).

## **NodeMCU**

We are using ESP8266 12E on a NodeMCU Development Board. Information on ModeMCU can be found at [NodeMcu -- An open-source firmware based on ESP8266 wifi-soc.](http://www.nodemcu.com/index_en.html). NodeMCU is an ESP8266 on a custom dev board with a firmware written in MicroPython that incorporates GPIO, PWM, IIC, 1-Wire and ADC functions, along with a Lua environment and built-in libraries to use Wifi, MQTT, telnet, etc. The schematic for NodeMCU can be found at [https://raw.githubusercontent.com/nodemcu/nodemcu-devkit/master/Documents/NODEMCU\_DEVKIT\_SCH.png](https://raw.githubusercontent.com/nodemcu/nodemcu-devkit/master/Documents/NODEMCU_DEVKIT_SCH.png). All NodeMCU-related information is at [NodeMCU · GitHub](https://github.com/nodemcu). The firmware repository is at [GitHub - nodemcu/nodemcu-firmware: Lua based interactive firmware for ESP8266, ESP8285 and ESP32](https://github.com/nodemcu/nodemcu-firmware).

The NodeMCU-devkits has a CP2102 USB to UART bridge and a voltage regulator on board each. So, we can connect the NodeMCU-devkit with a normal USB cable to a PC for communication and power supply. Furthermore, the module has an auto program circuit, which controls the activation of the boot-loader. No key must be pressed. We have to consider 3.3 V logic levels only for digital IO; one will need to level shift any 5 V signals running into the NodeMCU device.