Published September 19, 2020

Get the Thingspeak graphs on Blackkeyhole mobile app

In my tutorials, I had shown you how to make stuffs with DH11 sensor but this time I will show you how to make Custom app using MIT app Ine

BeginnerFull instructions provided1 hour642

Get the Thingspeak graphs on Blackkeyhole mobile app

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

DHT11 Temperature & Humidity Sensor (4 pins)

UTSOURCE Electronic Parts

Software apps and online services

Arduino IDE

MIT App Inventor

Story

In my tutorials, I had shown you how to make stuffs with DH11 sensor but this time I will show you how to make Custom app using MIT app Ineventor. Here I have used DH11 sensor for monitoring the data. You can use any other sensors to send data to Thingspeak cloud service. Here I have used DH11 sensor for monitoring Humidity and temperature values. Here I have deployed an android app for track the live data with the analytical report due to reduce the waste of time by go to Thingspeak website for monitoring the live data.

Components

1.DH11 sensor

2. NodeMcu

Things Speak

1. Go to https://thingspeak.com/and create an account.if you have already one. Login to your account.

2. Create a new channel by clicking on the button. Enter the basic details of the channel with how many fields, you have to use. Then Scroll down and save the channel. You can follow the video guide below.3. Then go to API keys copy and paste the write key to a separate notepad file. You will need it later while programming.

Thanks UTSOURCE.net to offer electronic components for my projects

MIT App Inventor

Follow the steps for creating App, from my video tutorial you can download my App for edit as per your wish

Click here to download the App

Code

Copy this program and paste it on Arduino IDE.
Download the DHT11/DHT22 library from GitHub and add it to your library manager.
Select the NodeMCU ESP-12E board from the board manager.
Paste your API Key from thingspeak which you created earlier on a programming section line.
Edit the program to change the wifi SSID and password with your own.
Compile the code and Upload it to NodeMCU board

Through Your mobile application, You can visualize the Chart view as well as you can check current values and past values with GMT time and date of Temperature and Humidity data. You can change the sensor as you wish. Hope You Have Liked this post and don't forget to share between who aspire to make this project.

Code

code

#include <DHT.h>
#include <ESP8266WiFi.h>
 
String apiKey = "SZMO9RDMUZCKWHT4";     //  Enter your Write API key from ThingSpeak
 
const char *ssid =  "ZTE WIFI";     // replace with your wifi ssid and wpa2 key
const char *pass =  "kl2229834";
const char* server = "api.thingspeak.com";
 
#define DHTPIN 0          //pin where the dht11 is connected
 
DHT dht(DHTPIN, DHT11);
 
WiFiClient client;
 
void setup() 
{
       Serial.begin(115200);
       delay(10);
       dht.begin();
 
       Serial.println("Connecting to ");
       Serial.println(ssid);
 
 
       WiFi.begin(ssid, pass);
 
      while (WiFi.status() != WL_CONNECTED) 
     {
            delay(500);
            Serial.print(".");
     }
      Serial.println("");
      Serial.println("WiFi connected");
 
}
 
void loop() 
{
  
      float h = dht.readHumidity();
      float t = dht.readTemperature();
      
              if (isnan(h) || isnan(t)) 
                 {
                     Serial.println("Failed to read from DHT sensor!");
                      return;
                 }
 
                         if (client.connect(server,80))   //   "184.106.153.149" or api.thingspeak.com
                      {  
                            
                             String postStr = apiKey;
                             postStr +="&field1=";
                             postStr += String(t);
                             postStr +="&field2=";
                             postStr += String(h);
                             postStr += "\r\n\r\n";
 
                             client.print("POST /update HTTP/1.1\n");
                             client.print("Host: api.thingspeak.com\n");
                             client.print("Connection: close\n");
                             client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
                             client.print("Content-Type: application/x-www-form-urlencoded\n");
                             client.print("Content-Length: ");
                             client.print(String(postStr.length()));
                             //client.print(postStr.length());
                             client.print("\n\n");
                             client.print(postStr);
 
                             Serial.print("Temperature: ");
                             Serial.print(t);
                             Serial.print(" degrees Celcius, Humidity: ");
                             Serial.print(h);
                             Serial.println("%. Send to Thingspeak.");
                        }
          else
         {
          ESP.restart();
         }    
          delay(200);          
          client.stop();
 
          Serial.println("Waiting...");
  
  // thingspeak needs minimum 15 sec delay between updates
  delay(1000);
}