ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (2022)

In this guide, you’ll learn how to make HTTP POST requests using the ESP32 board with Arduino IDE. We’ll demonstrate how to post JSON data or URL encoded values to two web APIs (ThingSpeak and IFTTT.com).

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (1)

Recommended: ESP32 HTTP GET with Arduino IDE (OpenWeatherMap.org and ThingSpeak)

HTTP POST Request Method

The Hypertext Transfer Protocol (HTTP) works as a request-response protocol between a client and server. Here’s an example:

  • The ESP32 (client) submits an HTTP request to a Server (for example: ThingSpeak or IFTTT.com);
  • The server returns a response to the ESP32 (client);
  • Finally, the response contains status information about the request and may also contain the requested content.

HTTP POST

POST is used to send data to a server to create/update a resource. For example, publish sensor readings to a server.

The data sent to the server with POST is stored in the request body of the HTTP request:

POST /update HTTP/1.1Host: example.comapi_key=api&field1=value1Content-Type: application/x-www-form-urlencoded

In the body request, you can also send a JSON object:

POST /update HTTP/1.1Host: example.com{api_key: "api", field1: value1}Content-Type: application/json

(With HTTP POST, data is not visible in the URL request. However, if it’s not encrypted, it’s still visible in the request body.)

Prerequisites

Before proceeding with this tutorial, make sure you complete the following prerequisites.

Arduino IDE

We’ll program the ESP32 using Arduino IDE, so make sure you have the ESP32 add-on installed.

  • Installing the ESP32 Board in Arduino IDE (Windows, Mac OS X, Linux)

Other Web Services or APIs

In this guide, you’ll learn how to setup your ESP32 board to perform HTTP requests to ThingSpeak and IFTTT.com. If you prefer to learn with a local solution you can use HTTP with Node-RED. All examples presented in this guide also work with other APIs.

In summary, to make this guide compatible with any service, you need to search for the service API documentation. Then, you need the server name (URL or IP address), and parameters to send in the request (URL path or request body). Finally, modify our examples to integrate with any API you want to use.

1. ESP32 HTTP POST Data (ThingSpeak)

In this example, the ESP32 makes an HTTP POST request to send a new value to ThingSpeak.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (2)

Using ThingSpeak API

ThingSpeak has a free API that allows you to store and retrieve data using HTTP. In this tutorial, you’ll use the ThingSpeak API to publish and visualize data in charts from anywhere. As an example, we’ll publish random values, but in a real application you would use real sensor readings.

(Video) ESP32 DHT11/DHT22 Asynchronous Web Server (auto updates Temperature and Humidity)

To use ThingSpeak API, you need an API key. Follow the next steps:

  1. Go to ThingSpeak.com and create a free account.
  2. Then, open the Channels tab.
  3. Create a New Channel.
ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (3)
  1. Open your newly created channel and select the API Keys tab to copy your API Key.
ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (4)

Code ESP32 HTTP POST ThingSpeak

Copy the next sketch to your Arduino IDE:

/* Rui Santos Complete project details at Complete project details at https://RandomNerdTutorials.com/esp32-http-post-ifttt-thingspeak-arduino/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files. The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.*/#include <WiFi.h>#include <HTTPClient.h>const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";// Domain Name with full URL Path for HTTP POST Requestconst char* serverName = "http://api.thingspeak.com/update";// Service API KeyString apiKey = "REPLACE_WITH_YOUR_API_KEY";// THE DEFAULT TIMER IS SET TO 10 SECONDS FOR TESTING PURPOSES// For a final application, check the API call limits per hour/minute to avoid getting blocked/bannedunsigned long lastTime = 0;// Set timer to 10 minutes (600000)//unsigned long timerDelay = 600000;// Timer set to 10 seconds (10000)unsigned long timerDelay = 10000;void setup() { Serial.begin(115200); WiFi.begin(ssid, password); Serial.println("Connecting"); while(WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } Serial.println(""); Serial.print("Connected to WiFi network with IP Address: "); Serial.println(WiFi.localIP()); Serial.println("Timer set to 10 seconds (timerDelay variable), it will take 10 seconds before publishing the first reading."); // Random seed is a number used to initialize a pseudorandom number generator randomSeed(analogRead(33));}void loop() { //Send an HTTP POST request every 10 seconds if ((millis() - lastTime) > timerDelay) { //Check WiFi connection status if(WiFi.status()== WL_CONNECTED){ WiFiClient client; HTTPClient http; // Your Domain name with URL path or IP address with path http.begin(client, serverName); // Specify content-type header http.addHeader("Content-Type", "application/x-www-form-urlencoded"); // Data to send with HTTP POST String httpRequestData = "api_key=" + apiKey + "&field1=" + String(random(40)); // Send HTTP POST request int httpResponseCode = http.POST(httpRequestData); /* // If you need an HTTP request with a content type: application/json, use the following: http.addHeader("Content-Type", "application/json"); // JSON data to send with HTTP POST String httpRequestData = "{\"api_key\":\"" + apiKey + "\",\"field1\":\"" + String(random(40)) + "\"}"; // Send HTTP POST request int httpResponseCode = http.POST(httpRequestData);*/ Serial.print("HTTP Response code: "); Serial.println(httpResponseCode); // Free resources http.end(); } else { Serial.println("WiFi Disconnected"); } lastTime = millis(); }}

View raw code

Setting your network credentials

Modify the next lines with your network credentials: SSID and password. The code is well commented on where you should make the changes.

// Replace with your network credentialsconst char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";

Setting your API Key

Modify the apiKey variable to include your ThingSpeak API key.

String apiKey = "REPLACE_WITH_YOUR_API_KEY";

Now, upload the code to your board and it should work straight away. Read the next section, if you want to learn how to make the HTTP POST request.

HTTP POST Request

In the loop() is where you make the HTTP POST request with URL encoded data every 10 seconds with random data:

// Specify content-type headerhttp.addHeader("Content-Type", "application/x-www-form-urlencoded");// Data to send with HTTP POSTString httpRequestData = "api_key=" + apiKey + "&field1=" + String(random(40));// Send HTTP POST requestint httpResponseCode = http.POST(httpRequestData);

For example, the ESP32 makes a URL encoded request to publish a new value (30) to field1.

POST /update HTTP/1.1Host: api.thingspeak.comapi_key=api&field1=30Content-Type: application/x-www-form-urlencoded

Or you can uncomment these next lines to make a request with JSON data (instead of URL-encoded request):

// If you need an HTTP request with a content type: application/json, use the following:http.addHeader("Content-Type", "application/json");// JSON data to send with HTTP POSTString httpRequestData = "{\"api_key\":\"" + apiKey + "\",\"field1\":\"" + String(random(40)) + "\"}";// Send HTTP POST requestint httpResponseCode = http.POST(httpRequestData);

Here’s a sample HTTP POST request with JSON data:

POST /update HTTP/1.1Host: api.thingspeak.com{api_key: "api", field1: 30}Content-Type: application/json

Then, the following lines print the server response code.

Serial.print("HTTP Response code: ");Serial.println(httpResponseCode);

In the Arduino IDE serial monitor, you should see an HTTP response code of 200 (this means that the request has succeeded).

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (5)
(Video) Control ESP32 and ESP8266 GPIOs from Anywhere in the World

Your ThingSpeak Dashboard should be receiving new random readings every 10 seconds.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (6)

For a final application, you might need to increase the timer or check the API call limits per hour/minute to avoid getting blocked/banned.

2. ESP32 HTTP POST (IFTTT.com)

In this example you’ll learn how to trigger a web API to send email notifications. As an example, we’ll use the IFTTT.com API. IFTTT has has a free plan with lots of useful automations.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (7)

Using IFTTT.com Webhooks API

IFTTT stands for “If This Than That”, and it is a free web-based service to create chains of simple conditional statements called applets.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (8)

This means you can trigger an event when something happens. In this example, the applet sends three random values to your email when the ESP32 makes a request. You can replace those random values with useful sensor readings.

Creating an IFTTT Account

If you don’t have an IFTTT account, go the IFTTT website: ifttt.com and enter your email to create an account and get started. Creating an account on IFTTT is free!

Next, you need to create a new applet. Follow the next steps to create a new
applet:

1. Open the left menu and click the “Create” button.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (9)

2. Click on the “this” word. Search for the “Webhooks” service and select the Webhooks icon.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (10)

3. Choose the “Receive a web request” trigger and give a name to the event. In this case, I’ve typed “test_event”. Then, click the “Create trigger” button.

(Video) ESP32/ESP8266 Plot Sensor Readings in Real Time Charts - Web Server

4. Click the “that” word to proceed. Now, define what happens when the event you’ve defined is triggered. Search for the “Email” service and select it. You can leave the default options.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (11)

5. Press the “Finish” button to create your Applet.

Testing Your Applet

Before proceeding with the project, it’s important to test your Applet first. Follow the next steps to test it:

1. Search for Webhooks service or open this link: https://ifttt.com/maker_webhooks

2. Click the “Documentation” button.

A page as shown in the following figure shows up. The page shows your unique API key. You should not share your unique API key with anyone.

3. Fill the “To trigger an Event” section. Then, click the “Test it” button.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (13)

4. The event should be successfully triggered, and you’ll get a green message saying “Event has been triggered”.

5. Go to your Email account. You should have a new email in your inbox from the IFTTT service with the values you’ve defined in the previous step.

If you’ve received an email with the data entered in the test request, it means your Applet is working as expected. Now, we need to program the ESP32 to send an HTTP POST request to the IFTTT service with the sensor readings.

Code ESP32 HTTP POST Webhooks IFTTT.com

After installing the necessary board add-ons and libraries, copy the following code to your Arduino IDE, but don’t upload it yet. You need to make some changes to make it work for you.

/* Rui Santos Complete project details at Complete project details at https://RandomNerdTutorials.com/esp32-http-post-ifttt-thingspeak-arduino/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files. The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.*/#include <WiFi.h>#include <HTTPClient.h>const char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";// Domain Name with full URL Path for HTTP POST Request// REPLACE WITH YOUR EVENT NAME AND API KEY - open the documentation: https://ifttt.com/maker_webhooksconst char* serverName = "http://maker.ifttt.com/trigger/REPLACE_WITH_YOUR_EVENT/with/key/REPLACE_WITH_YOUR_API_KEY";// Example://const char* serverName = "http://maker.ifttt.com/trigger/test_event/with/key/nAZjOphL3d-ZO4N3k64-1A7gTlNSrxMJdmqy3tC";// THE DEFAULT TIMER IS SET TO 10 SECONDS FOR TESTING PURPOSES// For a final application, check the API call limits per hour/minute to avoid getting blocked/bannedunsigned long lastTime = 0;// Set timer to 10 minutes (600000)//unsigned long timerDelay = 600000;// Timer set to 10 seconds (10000)unsigned long timerDelay = 10000;void setup() { Serial.begin(115200); WiFi.begin(ssid, password); Serial.println("Connecting"); while(WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } Serial.println(""); Serial.print("Connected to WiFi network with IP Address: "); Serial.println(WiFi.localIP()); Serial.println("Timer set to 10 seconds (timerDelay variable), it will take 10 seconds before publishing the first reading."); // Random seed is a number used to initialize a pseudorandom number generator randomSeed(analogRead(33));}void loop() { //Send an HTTP POST request every 10 seconds if ((millis() - lastTime) > timerDelay) { //Check WiFi connection status if(WiFi.status()== WL_CONNECTED){ WiFiClient client; HTTPClient http; // Your Domain name with URL path or IP address with path http.begin(client, serverName); // Specify content-type header http.addHeader("Content-Type", "application/x-www-form-urlencoded"); // Data to send with HTTP POST String httpRequestData = "value1=" + String(random(40)) + "&value2=" + String(random(40))+ "&value3=" + String(random(40)); // Send HTTP POST request int httpResponseCode = http.POST(httpRequestData); /* // If you need an HTTP request with a content type: application/json, use the following: http.addHeader("Content-Type", "application/json"); // JSON data to send with HTTP POST String httpRequestData = "{\"value1\":\"" + String(random(40)) + "\",\"value2\":\"" + String(random(40)) + "\",\"value3\":\"" + String(random(40)) + "\"}"; // Send HTTP POST request int httpResponseCode = http.POST(httpRequestData); */ Serial.print("HTTP Response code: "); Serial.println(httpResponseCode); // Free resources http.end(); } else { Serial.println("WiFi Disconnected"); } lastTime = millis(); }}

View raw code

(Video) ESP32 Publish Data to Cloud without Wi-Fi (TTGO T-Call ESP32 SIM800L)

Setting your network credentials

Modify the next lines with your network credentials: SSID and password. The code is well commented on where you should make the changes.

// Replace with your network credentialsconst char* ssid = "REPLACE_WITH_YOUR_SSID";const char* password = "REPLACE_WITH_YOUR_PASSWORD";

Setting your IFTTT.com API Key

Insert your event name and API key in the following line:

const char* serverName = "http://maker.ifttt.com/trigger/REPLACE_WITH_YOUR_EVENT/with/key/REPLACE_WITH_YOUR_API_KEY";

Example URL:

const char* serverName = "http://maker.ifttt.com/trigger/test_event/with/key/nAZjOphL3d-ZO4N3k64-1A7gTlNSrxMJdmqy3t";

HTTP POST Request

In the loop() is where you make the HTTP POST request every 10 seconds with sample data:

// Specify content-type headerhttp.addHeader("Content-Type", "application/x-www-form-urlencoded");// Data to send with HTTP POSTString httpRequestData = "value1=" + String(random(40)) + "&value2=" + String(random(40))+ "&value3=" + String(random(40));// Send HTTP POST requestint httpResponseCode = http.POST(httpRequestData);

The ESP32 makes a new URL encoded request to publish some random values in the value1, value2 and value3 fields. For example:

POST /trigger/test_event/with/key/nAZjOphL3d-ZO4N3k64-1A7gTlNSrxMJdmqy3tC HTTP/1.1Host: maker.ifttt.comvalue1=15&value2=11&value3=30Content-Type: application/x-www-form-urlencoded

Alternatively, you can uncomment these next lines to make a request with JSON data:

// If you need an HTTP request with a content type: application/json, use the following:http.addHeader("Content-Type", "application/json");// JSON data to send with HTTP POSTString httpRequestData = "{\"value1\":\"" + String(random(40)) + "\",\"value2\":\"" + String(random(40)) + "\",\"value3\":\"" + String(random(40)) + "\"}";// Send HTTP POST requestint httpResponseCode = http.POST(httpRequestData);

Here’s an example of HTTP POST request with a JSON data object.

POST /trigger/test_event/with/key/nAZjOphL3d-ZO4N3k64-1A7gTlNSrxMJdmqy3tC HTTP/1.1Host: maker.ifttt.com{value1: 15, value2: 11, value3: 30}Content-Type: application/json

Then, the following lines of code print the HTTP response from the server.

Serial.print("HTTP Response code: ");Serial.println(httpResponseCode);

HTTP POST Demonstration

After uploading the code, open the Serial Monitor and you’ll see a message printing the HTTP response code 200 indicating that the request has succeeded.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (14)

Go to your email account, and you should get a new email from IFTTT with three random values. In this case: 38, 20 and 13.

ESP32 HTTP POST with Arduino IDE (ThingSpeak and IFTTT.com) | Random Nerd Tutorials (15)

For demonstration purposes, we’re publishing new data every 10 seconds. However, for a long term project you should increase the timer or check the API call limits per hour/minute to avoid getting blocked/banned.

Wrapping Up

In this tutorial you’ve learned how to integrate your ESP32 with web services using HTTP POST requests. You can also make HTTP GET requests with the ESP32.

If you’re using an ESP8266 board, read:

  • Guide for ESP8266 NodeMCU HTTP GET Request
  • Guide for ESP8266 NodeMCU HTTP POST Request

You might also like reading:

(Video) Build an ESP8266 Web Server with Arduino IDE - Code and Schematics

  • [Course] Learn ESP32 with Arduino IDE
  • ESP32/ESP8266 Send Email Notification using PHP Script
  • Visualize Your Sensor Readings from Anywhere in the World
  • ESP32 Relay Module Web Server

I hope you liked this project. If you have any questions, post a comment below and we’ll try to get back to you.

If you like ESP32, you might consider enrolling in our course “Learn ESP32 with Arduino IDE“. You can also access our free ESP32 resources here.

Thank you for reading.

FAQs

How do I transfer data from ESP32 to ThingSpeak? ›

After inserting your network credentials, channel number and API key, upload the code to your board. Open the Serial Monitor at a baud rate of 115200, and press the on-board RST button. After 30 seconds, it should connect to Wi-Fi and start publishing the readings to ThingSpeak.

How do I use Ifttt with ESP32? ›

How to make ESP32 trigger IFTTT
  1. Create an IFTTT account.
  2. Login to IFTTT.
  3. Create an Applet, which connect Webhooks to a desired service (e.g Email, Twitter, VoIP ...)
  4. Go to Webhooks's document page to get the Webhooks key.
  5. Write ESP32 code to make HTTP (POST or GET) request to Webhooks.

How does ESP32 read data from ThingSpeak? ›

ESP32 Send Sensor Readings to ThingSpeak using Arduino IDE (BME280)
  1. Introduction to BME280 sensor.
  2. Connecting BME280 sensor with the ESP32 development board.
  3. Setting up Arduino IDE.
  4. Getting ThingSpeak API Ready.
  5. Publish to a single field of sensor readings to ThingSpeak (Only Temperature)

How do I connect my ESP32 to my website? ›

You can access the ESP32 web server by typing the ESP32 IP address on a browser in the local network; By clicking the buttons on your web server you can instantly change the state of each LED.

How do I transfer data from ESP32 to cloud? ›

Now go to Tools--> Board--> ESP32 Dev Module.
  1. Now go to Tools-->Port and select port to which your ESP32 is connected.
  2. Now click on upload to upload the code.
  3. After complete uploading you will find message like this in your output console.

How send data from Arduino to ThingSpeak? ›

ESP8266 IOT Using Arduino and ThingSpeak
  1. Step 1: Materials You Need. You will need: ...
  2. Step 2: Setup. Connect SFE Duino and ESP-8266 Wirelss Module with jumper wires as schematic above.
  3. Step 3: Connect With ThingSpeak. ...
  4. Step 4: Code. ...
  5. Step 5: Monitor It! ...
  6. 19 Comments.

How do I transfer data from Ifttt to ThingSpeak? ›

ThingSpeak, IFTTT, Temp and Humidity Sensor and Google Sheet
  1. Step 1: Hardware and Software Required. ...
  2. Step 2: Uploading the Code to ESP32 Using Arduino IDE. ...
  3. Step 3: Serial Monitor Output. ...
  4. Step 4: Output. ...
  5. Step 5: Create an IFTTT Applet. ...
  6. Step 6: Create a MATLAB Analysis. ...
  7. Step 7: Create a Time Control to Run Your Analysis.

How do I transfer data to Ifttt? ›

If you don't have an IFTTT account, start by creating one over at IFTTT.com.
...
Start sending data with IFTTT
  1. Turn on a light in your office when you get a new “plan_enterprise” user.
  2. Create a calendar event to follow up users who enter the “Signed Up” segment.
  3. Email to your success team when a user triggers “payment_failed”
Feb 13, 2018

What is ESP32 camera? ›

ESP32-CAM is a low-cost ESP32-based development board with onboard camera, small in size. It is an ideal solution for IoT application, prototypes constructions and DIY projects. The board integrates WiFi, traditional Bluetooth and low power BLE , with 2 high- performance 32-bit LX6 CPUs.

How do I extract data from ThingSpeak? ›

Parameters
  1. Sign in to ThingSpeak using your MATLAB account.
  2. Select Channels > My Channels.
  3. Select the channel from which to read data.
  4. Click the Channel Settings tab and copy the channel ID from the Channel ID parameter.
  5. Open the ThingSpeak Read block in your model and paste the copied ID to the Channel ID parameter.

How do I get data from ThingSpeak to my website? ›

Fetching Data From ThingSpeak IoT Cloud
  1. Download the JQuery library. ...
  2. Copy the code.
  3. Create an HTML file in the same directory as the JQuery library.
  4. Paste the code in the HTML file.
  5. Make sure you change the channel ID in the GetData() function to fetch data from your device channel. ...
  6. Save and close the HTML file.
Sep 3, 2016

How do I transfer data from ESP32 to AWS? ›

To communicate with the ESP32 device, it must connect to AWS IoT Core with device credentials. You must also specify the topics it has permissions to publish and subscribe on. In the AWS IoT console, choose Register a new thing, Create a single thing.

Can ESP32 run a web server? ›

The HTTP Server component provides an ability for running a lightweight web server on ESP32.

How can I control ESP32 remotely? ›

Easy IOT – Remotely Controlling ESP32 Using an Android App
  1. Step 1: Setting Up the Arduino IDE. Step 1 – The first thing we will need to do is add the ESP32 board to the Arduino IDE. ...
  2. Step 2: Arduino Webserver Code. ...
  3. Step 3: Find the ESP32 IP Address. ...
  4. Step 4: The DroidScript App. ...
  5. Step 5: Connect the Relay Module. ...
  6. Step 6: Test!

How can I get public IP ESP32? ›

How to get current gateway IP address on ESP8266/ESP32
  1. WiFi. gatewayIP(); WiFi.gatewayIP();
  2. Serial. println("Gateway IP address: "); Serial. println(WiFi. gatewayIP()); ...
  3. String gatewayIP = WiFi. gatewayIP(). toString(); String gatewayIP = WiFi.gatewayIP().toString();
Feb 7, 2021

How do you send data to ThingSpeak? ›

Parameters
  1. Sign in to ThingSpeak using your MATLAB account.
  2. Select Channels > My Channels.
  3. Select the channel to get the read API key.
  4. Click the API Keys tab and copy the key from the Write API Key parameter.
  5. Open the ThingSpeak Read block in your model and paste the copied API key in the Write API key parameter.

How do I transfer data from ESP32 to AWS? ›

To communicate with the ESP32 device, it must connect to AWS IoT Core with device credentials. You must also specify the topics it has permissions to publish and subscribe on. In the AWS IoT console, choose Register a new thing, Create a single thing.

How do I use Arduino IoT cloud? ›

To use the Arduino IoT Cloud, a cloud compatible board is required. You can choose between using an official Arduino board, or a board based on the ESP32 / ESP8266 microcontroller. The Arduino IoT Cloud currently supports connection via Wi-Fi, LoRaWAN® (via The Things Network) and mobile networks.

How to make HTTP POST requests using the ESP32 and the Arduino environment.

For sending HTTP GET requests with the same library, please check this previous tutorial.. Important: At the time of writing this tutorial, the HTTPClient.h library had just been merged to the ESP32 libraries for the Arduino environment.. Check how to do it.. If you need a detailed guide on how to connect to a WiFi network with the ESP32, please check this previous tutorial.. Before updating the ESP32 libraries, this delay was not needed.. After the initialization code, we will go for the main loop, where we will write the code needed for making the HTTP POST requests.. We will declare an object of class HTTPClient , which makes available the methods needed for handling the HTTP protocol.. Then, we call the begin method on the previously declared object and pass as input the URL for the website where we want to make the POST request.. After that, we will call the addHeader method, which will allow us to specify the HTTP request headers.. Now, to send the actual HTTP request, we call the POST method, passing as input the body content of the request.. This method will return the HTTP response code, which we will store in a variable.. Since we stored the HTTP response code, we will use it for error handling, as we will see the code bellow.. It also includes a delay between each request, and a conditional block to check if we are still connected to the WiFi network before sending a request.. Figure 1 – Output of the program to send HTTP POST Requests with the ESP32.Note that a HTTP 201 code is returned, which corresponds to “created” [2].. Since this is a fake testing website, nothing is happening on the backend and this is a simulated response, so all the following POST requests will return the same ID.

Establishing HTTP communication between two ESP32 devices.

This node could have the role of receiving data from the other devices and send it to the server and / or receiving configurations from the server and forward them to the devices.. Moving on to the Arduino setup, we will start by opening a serial connection, to output some results of our program, and then connect the device to the WiFi network, using the previously defined credentials.. The implementation of the route handling function will consist o printing a message to the serial port indicating a request was received, and then sending back an answer to the client.. We can return an answer back to the client by calling the send method on this object, passing as first input the HTTP response code, as second input the content-type and as third input the response payload.. Note that the Arduino main loop can be left empty since the HTTP web server framework we are using works asynchronously, which means we don’t need to periodically call a function to explicitly handle the incoming client requests.. Our Arduino setup function will consist on opening a serial connection and then connecting the device to the WiFi network.. We will write the rest of our code in the Arduino main loop function, to ensure the client will periodically send a HTTP GET request to the server.. As already mentioned, after running the code from the previous section in the ESP32 that will act as a server, it should print its local IP address once it connects to the WiFi network.. This method takes no arguments and returns as output an integer with the HTTP response code from the server, in case the request is successfully sent.. Figure 1 – Output of the ESP32 acting as a server, which shows the messages getting printed when requests are received.If you analyze the results getting printed to the ESP32 that is acting as a client, you should get a result like figure 2, which shows the 200 status code and the “Hello” message from the server getting printed.. Figure 2 – Output of the ESP32 acting as a client, showing the HTTP status code and response payload received from the server.

In this IoT ESP32 getting started tutorial, we program ESP32 using Arduino IDE and blink an LED.

ESP32 can be programmed directly from the Arduino IDE which makes it easy to work for the large community of Arduino developers.. Here in this ESP32 getting started tutorial , we will configure ESP32 in Arduino IDE and program it to Blink an LED .. Boot Button: Boot button is used to upload the program from Arduino IDE into ESP32 after clicking on the upload icon on the Arduino IDE.. I/O Pins: The ESP32 has more pins than ESP8266, With the ESP32 you can decide which pins are UART, SPI, or I2C.. USB-UART Bridge: The USB to UART Bridge Controller is a fully integrated USB to UART controller that provides USB connectivity to devices with a UART interface.. If you have already installed Arduino IDE on your PC, then make sure that it is the latest version of IDE as the older version doesn’t include the ESP32 board.. Step 2: After installing, open IDE and go to Files -> Preferences and open preference window and see the “Additional Boards Manager URL’s” as:. Step 5 : Now go to Tools-> Board-> Board Manager and search for ESP32 and press install , it will take some time to install, make sure that you have an internet connection; after installing, your window looks like this:. After this, close the window of board manager and your Arduino IDE is ready to program ESP32.. Following are the steps required to program the ESP32 with Arduino IDE.. Here we will upload an LED binky program in ESP32 using Arduino IDE.. Step 1: First of all, connect your ESP32 to your computer using a micro-USB cable, make sure that Red LED goes high after connecting it with the PC.. Step 4: Open Arduino IDE again and paste the given LED blink program:. You can also connect LED externally with ESP32 in that case you have to just change that PIN to which you are connecting the LED.. You can also connect the external LED with some GPIO pin of ESP32, just change the pin no.

Learn step by step tutorial to program ESP32 with Arduino IDE after Arduino has officially launched its support for ESP32 boards

So let’s start programming ESP32 with Arduino IDE and then you can try all the interesting IoT based projects using ESP32 .. Let’s take a look the ESP32 module.. Boot Button: This button is used to upload the Program from Arduino to the ESP module.. Unlike ESP8266, on ESP32 we can access all the I/O pin of the module through the break-out pins.. The first step would be to download and install the Arduino IDE .. STEP 4: Now go to Tools -> Boards -> Board Managers to open the Board manager window and search for ESP32.. If the URL was pasted correctly your window should find the below screen with Install button, just click on the Install button and your board should get installed.. STEP 5: Make sure you have an active internet connection and wait while the installation gets complete.. That is it now our Arduino IDE is prepared to work with ESP32 .. STEP 1: Connect your ESP32 board to your computer through the micro-USB cable.. Make sure the red LED goes high on the module to ensure power supply.. STEP 2: Start the Arduino IDE and navigate to Tools -> Boards and select ESP32Dev board as shown below. STEP 5: Let’s upload the Blink Program, to check if we are able to program our ESP32 module.. My module with its LED blinking is shown below. This is how Programming ESP32 using Arduino IDE can be implemented.

In this tutorial we are making ESP32 as both Station and Access point and web server. We have seen how to connect to WiFi Router and make web server in previous post. What you will Learn? Making ES…

As we know that all web servers have a HTML web page to be served.. First we make program to connect to WiFi hot spot (Access Point). WiFiClient.h this file is required to send request to web browser. This way you can access ESP web page with two different IP address.. When client request a web page by entering ESP32 IP address which data to be sent is handled by subroutine and that subroutine name is defined in server.on(path,subroutine_name).. Complete Program for HTML web Server from esp32 as Access Pointindex.h Make separate header file for storing HTML code.

Learn about ESP32 development board along with its Specifications, Datasheet, Pinout, Installing ESP32 Arduino Core on Windows, Mac, Linux & Troubleshooting

Multiplexed I/Os 15 ADC channels 2 UART interfaces 25 PWM outputs 2 DAC channels SPI, I2C & I2S interface 9 Touch Pads. The ESP32 development board features two buttons.. GPIO Pins ESP32 development board has 25 GPIO pins which can be assigned to various functions programmatically.. They don’t have an Arduino board manager install yet (Like we do while installing ESP8266 core on Arduino IDE).. They don’t have an Arduino board manager install yet (Like we do while installing ESP8266 core on Arduino IDE).. They don’t have an Arduino board manager install yet (Like we do while installing ESP8266 core on Arduino IDE).. Before we get to uploading sketch & playing with LED, we need to make sure that the board is selected properly in Arduino IDE.

Learn to read Date & Time from NTP Server with ESP32 as a Client along with NTP Working, Architecture, Code with Explanation using Arduino IDE.

The protocol can be used to synchronize all networked devices to Coordinated Universal Time (UTC) within a few milliseconds ( 50 milliseconds over the public Internet and under 5 milliseconds in a LAN environment).. Coordinated Universal Time (UTC) is a world-wide time standard, closely related to GMT (Greenwich Mean Time).. NTP sets the clocks of computers to UTC, any local time zone offset or day light saving time offset is applied by the client.. Stratum 1 servers have a direct connection to a stratum 0 hardware clock and therefore have the most accurate time.. The following sketch will give you complete understanding on how to get date and time from the NTP Server.. Once ESP32 is connected to the network, we initialize the NTP client using configTime() function to get date and time from an NTP server.. You can access the date & time information by accessing members of this time structure.

Learn how to use the Espressif ESP32 microcontroller with the Arduino IDE. Step-by-step instructions for getting started with the ESP32.

* The API is almost the same as with the WiFi Shield library,. * the most obvious difference being the different file you need to include:. */. #include "WiFi.h". void setup(). {. Serial.begin(115200);. // Set WiFi to station mode and disconnect from an AP if it was previously connected. WiFi.mode(WIFI_STA);. WiFi.disconnect();. delay(100);. Serial.println("Setup done");. }. void loop(). {. Serial.println("scan start");. // WiFi.scanNetworks will return the number of networks found. int n = WiFi.scanNetworks();. Serial.println("scan done");. if (n == 0) {. Serial.println("no networks found");. } else {. Serial.print(n);. Serial.println(" networks found");. for (int i = 0; i < n; ++i) {. // Print SSID and RSSI for each network found. Serial.print(i + 1);. Serial.print(": ");. Serial.print(WiFi.SSID(i));. Serial.print(" (");. Serial.print(WiFi.RSSI(i));. Serial.print(")");. Serial.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?". Point your web browser to http://192.168.4.1/H to turn the LED on or http://192.168.4.1/L to turn it off. OR. Run raw TCP "GET /H" and "GET /L" on PuTTY terminal with 192.168.4.1 as IP address and 80 as port. Created for arduino-esp32 on 04 July, 2018. by Elochukwu Ifediora (fedy0). */. #include . #include . #include . #define LED_BUILTIN 2 // Set the GPIO pin where you connected your test LED or comment this line out if your dev board has a built-in LED. // Set these to your desired credentials.. // that's the end of the client HTTP request, so send a response:. if (currentLine.length() == 0) {. // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK). // and a content-type so the client knows what's coming, then a blank line:. client.println("HTTP/1.1 200 OK");. client.println("Content-type:text/html");. client.println();. // the content of the HTTP response follows the header:. client.print("Click here to turn ON the LED.
");. client.print("Click here to turn OFF the LED.
");. // The HTTP response ends with another blank line:. client.println();. // break out of the while loop:. break;. } else { // if you got a newline, then clear currentLine:. currentLine = "";. }. } else if (c != '\r') { // if you got anything else but a carriage return character,. currentLine += c; // add it to the end of the currentLine. }. // Check to see if the client request was "GET /H" or "GET /L":. if (currentLine.endsWith("GET /H")) {. digitalWrite(LED_BUILTIN, HIGH); // GET /H turns the LED on. }. if (currentLine.endsWith("GET /L")) {. digitalWrite(LED_BUILTIN, LOW); // GET /L turns the LED off. }. }. }. // close the connection:. client.stop();. Serial.println("Client Disconnected.. Circuit:. * WiFi shield attached. * LED attached to pin 5. created for arduino 25 Nov 2012. by Tom Igoe. ported for sparkfun esp32. 31.01.2017 by Jan Hendrik Berlin. */. #include . const char* ssid = "yourssid";. const char* password = "yourpasswd";. WiFiServer server(80);. void setup(). {. Serial.begin(115200);. pinMode(2, OUTPUT); // set the LED pin mode. delay(10);. // We start by connecting to a WiFi network. Serial.println();. Serial.println();. Serial.print("Connecting to ");. Serial.println(ssid);. WiFi.begin(ssid, password);. while (WiFi.status() != WL_CONNECTED) {. delay(500);. Serial.print(".. // that's the end of the client HTTP request, so send a response:. if (currentLine.length() == 0) {. // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK). // and a content-type so the client knows what's coming, then a blank line:. client.println("HTTP/1.1 200 OK");. client.println("Content-type:text/html");. client.println();. // the content of the HTTP response follows the header:. client.print("Click here to turn the LED on pin 2 on.
");. client.print("Click here to turn the LED on pin 2 off.
");. // The HTTP response ends with another blank line:. client.println();. // break out of the while loop:. break;. } else { // if you got a newline, then clear currentLine:. currentLine = "";. }. } else if (c != '\r') { // if you got anything else but a carriage return character,. currentLine += c; // add it to the end of the currentLine. }. // Check to see if the client request was "GET /H" or "GET /L":. if (currentLine.endsWith("GET /H")) {. digitalWrite(2, HIGH); // GET /H turns the LED on. }. if (currentLine.endsWith("GET /L")) {. digitalWrite(2, LOW); // GET /L turns the LED off. }. }. }. // close the connection:. client.stop();. Serial.println("Client Disconnected.. */. // use first channel of 16 channels (started from zero). #define LEDC_CHANNEL_0 0. // use 13 bit precission for LEDC timer. #define LEDC_TIMER_13_BIT 13. // use 5000 Hz as a LEDC base frequency. #define LEDC_BASE_FREQ 5000. // fade LED PIN (replace with LED_BUILTIN constant for built-in LED). #define LED_PIN 5. int brightness = 0; // how bright the LED is. int fadeAmount = 5; // how many points to fade the LED by. // Arduino like analogWrite. // value has to be between 0 and valueMax. void ledcAnalogWrite(uint8_t channel, uint32_t value, uint32_t valueMax = 255) {. // calculate duty, 8191 from 2 ^ 13 - 1. uint32_t duty = (8191 / valueMax) * min(value, valueMax);. // write duty to LEDC. ledcWrite(channel, duty);. }. void setup() {. // Setup timer and attach timer to a led pin. ledcSetup(LEDC_CHANNEL_0, LEDC_BASE_FREQ, LEDC_TIMER_13_BIT);. ledcAttachPin(LED_PIN, LEDC_CHANNEL_0);. }. void loop() {. // set the brightness on LEDC channel 0. ledcAnalogWrite(LEDC_CHANNEL_0, brightness);. // change the brightness for next time through the loop:. brightness = brightness + fadeAmount;. // reverse the direction of the fading at the ends of the fade:. if (brightness <= 0 || brightness >= 255) {. fadeAmount = -fadeAmount;. }. // wait for 30 milliseconds to see the dimming effect. delay(30);. }

Ever asked how to control any device from any place in the world? In this tutorial, we'll learn how to control things wirelessly over WiFi. By Ahmed Ibrahim Ahmed.

Smart home technology uses devices such as linking sensors, features and other appliances connected to the internet of things (IoT) that can be remotely monitored, controlled or accessed and provide services that respond to the needs of the users.Wikipedia Working ScenarioWe will build a simple web page that will work as a control panel for the user allows him to control any home appliance connected to our system.. the web page sends some orders to the ESP8266-01 which is working as a web server connected to the Arduino board.. Also, it’s very easy to use with the Arduino board since its a Serial wifi module it can communicate with the Arduino board over the serial communication.. ESP8266-01 ConfigurationAs we stated before the ESP8266-01 module communicates with the Arduino board over the Serial communication, which means that we need to connect it with the Arduino’s Serial pins 0, 1(Tx, Rx).. Javascript: it’s a programming language that we will use to make the web page more interactive like adding some animations, maps and it allows us to make some complex things on the web page.. Now, the web page looks nicer (NOT TOO MUCH xD) we gave it a cool green background color, we make the page content centered aligned, and we change the headers font color and font family which made the web page more alive.. Now, after building our web page structure and styling it we need to add some functionality to the two buttons which we added earlier in the web page.. In the Arduino code, we will receive this data and separate these two parts from each other and save each part in a different variable, part one in variable pinNumber and the second part in variable pinState , then we will write this simple line of code to control the connected load digitalWrite(pinNumber, pinState);. The Two-channel relay module has two control pins(IN1, IN2) these pins should get connected to two Arduino digital pins to control the state of the two coils, closes or opens the load circuit.. We will make a small modification to our web page, we will add another two buttons(ON and OFF) to control the second connected load.. Just like the last trial, You upload the Arduino code to the board (if not uploaded yet) and open the serial monitor and make sure that your ESP module is connected successfully to your access point and got an IP and MAC address.. Troubleshooting if your ESP Module is successfully connected to your access point but there is no action happens when you click the web page buttons. Don’t forget to save the Web page code file after any change or modification, and reload the web page in the web browser after any code modification to take effect.

What better time to learn IoT than today? In this tutorial, we are going to set up a web server using an Arduino and the ESP8266-01.

On the other hand, a web client needs to go through a server first to connect to another server or client.. The web browser sends the request to the web server that hosts Circuit Basics, which then returns the data needed to display the Circuit Basics homepage.. With an Arduino web server, you can already store a web page and extend control over your sensors and other connected devices.. The ESP8266 AT Commands allow users to perform operations like testing the connection, setting the mode of operation, connecting to WiFi, determining the IP address, etc.. These two libraries give access to functions that help you connect to a WiFi network, set up a server, and handle HTTP requests.. Moreover, using begin functions, we connect to the WiFi, start a server then initialize the DHT sensor and time server.

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