espThings

It's an ESP8266 project to measure Temperature and Humidity using SHT31 and Adafruit Huzzah ESP8266. It provides us Real Time Temperature and Humidity data and hourly analytics. The data is send to web Server hosted by the device and to Things Speak API

Features

Provides you real time analytics and stats using Thing Speak API
The sensor data can also be seen in Web Server hosted by the device
Task Scheduler are used to Schedule the task like fetching data from sensors, hosting a web server, posting the readings to cloud
It uses I2C protocol to fetch the sensor reading which are more accurate, expandableand scalable
sleep mode when device is idle or no task callback is called.
effective task scheduling provide hastle free usage

Parts Used

How it works

We have scheduled three tasks refering to three different control operations
Task 1 is for reading the sensor value this task runs for 1 second till it reaches timeout of 10 secs.
When the Task1 reaches its time out Task 2 is enabled and Task1 is disabled. We connect to AP in this callback two boolean variables are taken to
Two boolean variables are taken to take care of the switching between STA and AP
In Task 2 we are hosting a web server at 192.168.1.4 . This task runs for every 5 sec till it reaches its timeout which is 50 sec
When Task 2 reaches timeout Task 3 is enabled and Task2 is disabled. We connect to STA(local IP) in this calback
In Task 3 we are posting the sensor reading to cloud ThingSpeak API
Task 3 runs for every five seconds till it reached its timeout i.e 50 sec
When the Task3 reaches its time out Task 1 is enabled again and Task3 is disabled.
when no callback is called or the device is idle it goes to Light Sleep thus saving power.

Usage

Hosting a from webserver

connect to following url:

192.168.1.4

open the url connection using HttpUrlConnection:

192.168.1.4 is an intro page
192.168.1.4/Value gives the sensor value

POST data to thing speak

  if(wifiClient.connect(hostId,80)){
            String postStr = apiKey;
            postStr +="&field1=";
            postStr += String(humid);
            postStr +="&field2=";
            postStr += String(tempC);
            postStr +="&field3=";
            postStr += String(tempF);
            postStr += "\r\n\r\n";

            wifiClient.print("POST /update HTTP/1.1\n");
                             wifiClient.print("Host: api.thingspeak.com\n");
                             wifiClient.print("Connection: close\n");
                             wifiClient.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
                             wifiClient.print("Content-Type: application/x-www-form-urlencoded\n");
                             wifiClient.print("Content-Length: ");
                             wifiClient.print(postStr.length());
                             wifiClient.print("\n\n");
                             wifiClient.print(postStr);
          }
          wifiClient.stop();

Profile

Credits

Arduino JSON: https://arduinojson.org/v5/doc/encoding/
ESP8266: https://links2004.github.io/Arduino/d3/d58/class_e_s_p8266_web_server.html
TaskScheduler: https://github.com/arkhipenko/TaskScheduler
SHT 31: https://github.com/ControlEverythingCommunity/SHT31/blob/master/Arduino/SHT31.ino
I2C scan: https://github.com/bhaskar-anil429/arduino-i2c-scan
https://www.instructables.com/id/ESP8266-Temp-Humidity-Monitoring-Web-App-Using-Ard/
Wire: https://www.arduino.cc/en/Reference/Wire

Future Enhancement

To host another web page where the user can config its wifi credentials.
Deep sleep mode- We can put ESP to deep sleep mode to conserve power
To enhance the no. of sensors using i2c
Createa mesh network using ESp's.

bhaskar-anil429/espThings