Sending SHT25 Sensor data to google spreadsheet by using the gscript editor as a bridge

• Adafruit Huzzah ESP8266
• SHT25 Sensor
• Adafruit Huzzah I2C adapter
• I2C Cable

Fetching the readings of real-time data of sensors through ESP8266 and send the data to different Cloudplatforms is much simple.

We are going to use Wire.h library in Arduino IDE for creating the two wired communication between Adafruit Huzzah Board and SHT25 sensor I2C module and I2C cable.

For the newbie to setup the Esp8266 yo must go through the ESP8266 setup.

• First Initialize the the libraries:
  • I2C : #include <Wire.h>
  • ESP8266 WiFi : #include <ESP8266WiFi.h>
  • HTTPS WiFi Client : #include <WiFiClientSecure.h>

After Initializing libraries, we will be defining the I2C process to be used to fetch the sensor readings convert them and shift the 8 bits data as per the requirements:

• Initialize the registers in two wire I2C protocol for the I2C sensor module

  #define Addr 0x40
  

• Start I2C transmission and initialize the registers and request for 2 bytes data from where we will read the sensor data.

• If 2 bytes data will be available then read the sensor data and using mentioned below formulas we are converting the desired values

  float humidity = (((data[0] * 256.0 + data[1]) * 125.0) / 65536.0) - 6; 
  float cTemp = (((data[0] * 256.0 + data[1]) * 175.72) / 65536.0) - 46.85;
  float fTemp = (cTemp * 1.8) + 32;
  

• Print the values in a serial monitor screen

After the execution I2C modules we are going to learn about how to fetch the data and by using WiFi libraries and host id as well as API keys to send the data to google sheets.

• Define WiFi credentials globally in ESP8266 which will help us to connect the board with internet

• As we are going to use the HTTP client and will be defining HTTPS = 443 protocol for securing the HTTP path as the script will working in the secure path only.

• Initialize the host details in code

  const char* host = "script.google.com";
  const int httpsPort = 443; 
  String SCRIPT_ID = "<GScript Link ID>";
  

    /s/<Script ID>/exec

• Also using volatile with variable, we are going to initialize variable globally which fetch the data from the I2C module and send it to the URL script which will further send the data to the destination.
• Using ESP8266 WiFi Library we will be able to connect the board with internet
• The sensor data will be hosted to a local server after every 5s.
• With the help of URL script, the data will be hosted to google script published link Active page after every 15 seconds.

As we all have a google account to sign in to google sheet with your account

• Mention the values which you need to get from the sensor connected with ESP8266

• Go to Tools>Script Editor
• In Script Editor page mention the name

• Use "Doget" function to receive the events
• In "Doget" function to initialize the spreadsheet API key as well as connect the Active Sheet where you want to send the sensor values

• With the help of automation function to mentioned in the code to represent the data in rows and columns easily.
• Finally, save the data and click on “Publish”>> Click “Deploy as web apps”

• Make sure whenever there will be any change to select the “project version” >> “New”>> press “update”

Current web app URL will appear as below :

    https://script.google.com/macros/s/”<GScript API Key>”/exec:

further used in ESP8266 code for fetching the data from sensors

We are going to use the HTTPS Get request to connect the data to the host id mentioned in the gscript editor where we coded our data further to connect with google sheet.

    function doGet(e) { 
    Logger.log( JSON.stringify(e) );  // view parameters
    var result = 'Ok'; // assume success
    if (e.parameter == 'undefined') 
    {
      result = 'No Parameters';
      }
    else {
    var sheet_id = '<google spreadsheet Api Key>';       // Spreadsheet ID
    var sheet = SpreadsheetApp.openById(sheet_id).getActiveSheet();
    var newRow = sheet.getLastRow() + 1;                        
    var rowData = [];
     }
    Logger.log(JSON.stringify(rowData));
    // Write new row below
    var newRange = sheet.getRange(newRow, 1, 1, rowData.length);
    newRange.setValues([rowData]);
    }

• This project is only limited to store the data of I2C sensor in google sheets
• We are using HTTPS GET request to receive the values through I2C functions
• We have to change the value in string format and then send the data to gscript URL link.

I2C Sensor : https://github.com/ControlEverythingCommunity/SHT25

Spreadsheet with ESP8266: http://pdacontrolen.com/update-https-redirect-version-2-0-esp8266-google-spreadsheets/

Sensor moduele: https://store.ncd.io/product/sht25-humidity-and-temperature-sensor-%C2%B11-8rh-%C2%B10-2c-i2c-mini-module/

Datasheet : https://media.ncd.io/sites/2/20170721134452/Sensirion_Humidity_SHT25_Datasheet_V3.pdf