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Basics: Project 066i

Project name: ESP8266 ESP-12E module, LCD1602 I2C display module, DHT11/21/22 module-web server

Tags: ESP, ESP8266, WI FI module, ESP-12E, Ai Thinker, AI-Cloud, SOC, GPIO, General Purpose Input Output, System On a Chip, IOT, internet of things, FTDI232, FTDI 232, how to upload sketch, blink sketch for ESP8266 ESP-12E module, LoLin NODEMCU V3, NODEMCU, V3, Development Board with USB-to-Serial Onboard, NodeMCU DevKit, IOT STARTUP, LCD 1602 I2C display module, DHT11, DHT21, DHT22 module, PIR sensor, web server

Attachments: webserversketch, library1, library2, library3

In this project, you need these parts :

1. ESP8266 ESP-12E module with micro USB cable 1pc

2.Arduino IDE ( you can download it from here  )

3.Jumper cables F-M, F-F, M-M

4. Breadboard 1 pc

5. LCD1602 I2C display module 1 pc 

6. Resistor 1 pc (10 KOhm)

7. DHT11 21 22 Humidity and temperature module 1pc

General

We will learn how to make a web server that receives data (humidity and temperature readings) from DHT 11/21/22 module, using ESP8266 ESP-12E module (LoLin NODEMCU V3). We will also display humidity and temperature readings on the LCD1602 I2C module.

Understanding the LCD1602 I2C module

You can read more about it here.

Understanding the DHT 11 21 22 module

You can read more about it here.

Understanding the ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3)

You can read more about it here.

Signals and connections of the PIR sensor

Most PIR modules have a 3-pin connection at the side or bottom. The pinout may vary between modules. One pin will be ground, another will be signal and the final one will be power. Power is usually 3-5VDC input but may be as high as 12V. Sometimes larger modules don't have direct output and instead just operate a relay in which case there is ground, power and the two switch connections.The output of some relays may be 'open collector' - that means it requires a pullup resistor. If you're not getting a variable output be sure to try attaching a 10K pullup between the signal and power pins. An easy way of prototyping with PIR sensors is to connect it to a breadboard since the connection port is 0.1" spacing. Some PIRs come with header on them already, the one's from adafruit have a straight 3-pin header on them for connecting a cable.

Signals and connections of the DHT 11 21 22 module

There are two different versions of the DHT11 you might come across. One type has four pins, and the other type has three pins and is mounted to a small PCB. The PCB mounted version is nice because it includes a surface mounted 10K Ohm pull up resistor for the signal line. Here are the pin outs for both versions:

Signals and connections of the LCD1602 I2C module

As you can see on the back of LCD 1602 I2C module there 4 connections: GND (-), VCC (+5V), Serial Data Line (SDA) (Arduino Uno SDA or Analog pin A4) and Serial Clock Line (SCL) (Arduino Uno SCL or Analog pin A5).

Signals and connections of the ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3)

TX - transmit pin. GPIO pin

RX  - receive pin.  GPIO pin

3V3 (or 3V or 3.3V) - power supply pin (3-3.6V). 

GND ( or G) - ground pin.

RST - reset pin. Keep it on high (3.3V) for normal operation. Put it on 0V to reset the chip.

EN - Chip enable. Keep it on high (3.3V) for normal operation.

Vin - External power supply 5VDC.

D0-D8 - GPIO (General Purpose Input Output) pins 

D5-D8 - SPI interface

D1-D2– I²C/TWI Interface

SC (or CMD) - (Chip Select) - the pin that the master can use to enable and disable specific devices. GPIO pin

SO (or SDO) - Master In Slave Out (MISO) - SPI communication. The Slave line for sending data to the master. GPIO pin

SK (or CLK) - SCK (Serial Clock) - SPI communication.The clock pulses which synchronize data transmission generated by the master. GPIO pin

S1 (or SD1) - Master Out/Slave In (MOSI). SPI communication. The Master line for sending data to the peripherals. GPIO pin

S2 (or SD2) - GPIO pin

S3 (or SD3) - GPIO pin

VU (or VUSB) - external power 5VDC.

A0 - ADC output.

RSV - reserved

Wiring

Step by Step instruction

1. Adding ESP8266 platform to Arduino IDE

The Arduino environment has to be set up to make it compatible with the ESP8266 ESP-01 module. It is required to have Arduino IDE version 1.6.4 or higher in order to install the ESP8266’s platform packages.

1. Open Arduino IDE. 
2. Open the Preferences window from the Arduino IDE. Go to File -> Preferences.
3. 
4. Enter http://arduino.esp8266.com/stable/package_esp8266com_index.json into Additional Board Manager URLs field and click the “OK” button. If you already have a URL in there, and want to keep it, you can separate multiple URLs by placing a comma between them. (Arduino 1.6.5 added an expanded text box, separate links in here by line.)
5. 
   
6. Open Boards manager. Go to Tools -> Board -> Boards Manager…
7. 
   
8. There should be a couple new entries in addition to the standard Arduino boards. Look for esp8266. or scroll down to the ESP8266 entry (usually at the bottom). Select the ESP8266 entry. When you click it an install option will appear. Select the latest version and click install. 
9. 
10. The board definitions and tools for the ESP8266 include a whole new set of gcc, g++, and other reasonably large, compiled binaries, so it may take a few minutes to download and install (the archived file is ~110MB). Once the installation has completed, an Arduino-blue “INSTALLED” will appear next to the entry.
11. 
12. 

2. Uploading sketch to ESP8266 ESP-12E module 

 If you’re using an ESP-12E NodeMCU Kit, uploading the sketch is very simple, since it has built-in programmer. 

Before use ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3), you need to download the manufacture's driver (CH340)  for this chip and install it in your PC. Here is the link. See the description of driver installation package below: CH340 / CH341 USB to serial WINDOWS driver installation package that supports 32/64 bit Windows 10 / 8.1 / 8/7 / VISTA / XP, SERVER 2016/2012/2008/2003, 2000 / ME / 98, through Microsoft digital signature authentication, support USB to 3-wire and 9-wire serial port, with the product release To the end user. Applicable scope: CH340G, CH340C, CH340B, CH340E, CH340T, CH340R, CH341A, CH341T, CH341H chips.

If you have CP2102 chip then  you need to download the manufacture's driver for this chip and install it in your PC. Driver for Mac, Windows, Linux or more.. 

1. Do wiring.
2. Open Arduino IDE.
3. Plug your ESP8266 ESP-12E module into your PC USB port.
4. Choose your NodeMCU board. Go to Tools -> Board -> NodeMCU 1.0 (ESP-12E Module)
5. Select the correct com port.
6. Find your LCD1602 I2C address. Each device has an I2C address that it uses to  accept commands or send messages. Load the sketch over at http://playground.arduino.cc/Main/I2cScanner and follow the instructions to use it.  By opening up the Serial monitor window after you upload the sketch, Arduino will scan the address range looking for a reply.  Even though the documentation said it was 0x27, this scanner can detect different (in our case 0x3F)
7. Modify the sketch in attachments above (you can use the sketch below too): the line LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE) (See part marked bold)
8. Replace the SSID and password in the webserversketch with your own data.
9. Verify and upload the webserversketch to your ESP8266 ESP-12E module. AT commands will not work after that. You need to Flash the firmware to enable them again.
10. 
11. Open Serial monitor at baud rate of 9600 bps.
12. You will see the IP address of your ESP8266 ESP-12E module.
13. Open any browser from a device (PC, cell phone, tablet) that is connected to the same router that your ESP8266 ESP-12E module is.
14. Type the IP address (for example we had 192.168.0.117) which you have seen in Arduino IDE serial monitor and press Enter button.
15. 
16. Your web page instantly refreshes every 30 seconds. You can see humidity and temperature readings now. If the temperature more then 25 degrees C the color of font will change to red. If the temperature less then 5 degrees C the color of font will change to blue. If you check the serial monitor, you can see what’s happening on the background. The ESP receives an HTTP request from a new client – in this case, your browser. You can also see other information about the HTTP request – these fields are called HTTP header fields, and they define the operating parameters of an HTTP transaction.
17. You will also see the temperature,humidity displayed on LCD1602 I2C display module.

Summary

We have learnt how to make a web server that receives data (humidity and temperature readings) from DHT 11/21/22 module, using ESP8266 ESP-12E module (LoLin NODEMCU V3). We will also display humidity and temperature readings on the LCD1602 I2C module.

Library

• All libraries attached on the begining of this project description.
• ESP8266WiFi library included in Arduino IDE.
• We have used the library - NewliquidCrystal which we downloaded, unzipped, changed the name of folder to LiquidCristal and added to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC. If you have LiquidCristal folder in this location already - delete this folder and copy folder, which was made by you, to this location.
• Adafruit_Sensor library included.Download, unzip  and add to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC. 
• DHT-sensor library included. Download, unzip  and add to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC.  OR You can install it in Arduino IDE too: select Sketch-> Include library->Manage your libraries->type DHT in Filter your search line and you will see DHT sensor library by Adafruit->More info->select version->install. If it will be problem with compilation - remove 2 files from the library - DHT_U.cpp and DHT_U.h.

Sketch

• You can find it on the begining of this project