![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/ESP32-HTTP-GET-HTTP-POST-with-Arduino-IDE-JSON-URL-Encoded-Text.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nRecommended:<\/strong> ESP8266 NodeMCU HTTP GET and HTTP POST with Arduino IDE (JSON, URL Encoded, Text)<\/a><\/p>\n\n\n\n The Hypertext Transfer Protocol (HTTP) works as a request-response protocol between a client and server. Here’s an example:<\/p>\n\n\n\n GET <\/strong>is used to request data from a specified resource. It is often used to get values from APIs.<\/p>\n\n\n\n For example, you can have:<\/p>\n\n\n\n Note that the query string (name = temperature<\/em> and value = value1<\/em>) is sent in the URL of the HTTP GET request.<\/p>\n\n\n\n Or you can use a simple request to return a value or JSON object, for example:<\/p>\n\n\n\n (With HTTP GET, data is visible to everyone in the URL request.)<\/em><\/p>\n\n\n\n POST <\/strong>is used to send data to a server to create\/update a resource. For example, publish sensor readings to a server.<\/p>\n\n\n\n The data sent to the server with POST is stored in the request body of the HTTP request:<\/p>\n\n\n\n In the body request, you can also send a JSON object:<\/p>\n\n\n\n (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.)<\/em><\/p>\n\n\n\n In this guide, we’ll explore the following scenarios:<\/p>\n\n\n\n Before proceeding with this tutorial, make sure you complete the following prerequisites.<\/p>\n\n\n\n We’ll program the ESP32 using Arduino IDE, so make sure you have the ESP32 add-on installed.<\/p>\n\n\n\n You also need to install the Arduino_JSON library<\/a>. You can install this library in the Arduino IDE Library Manager. Just go to Sketch <\/strong>> Include Library<\/strong> > Manage Libraries<\/strong> and search for the library name as follows:<\/p>\n\n\n For this tutorial you need the following parts:<\/p>\n\n\n\n You can use the preceding links or go directly to MakerAdvisor.com\/tools<\/a> to find all the parts for your projects at the best price!<\/p> As an example, we’ll create a web service with a Raspberry Pi and Node-RED to act as a web service (like an API). Basically, you’ll make HTTP GET and HTTP POST requests to your Raspberry Pi to get values or update them. You can use any other web service.<\/p>\n\n\n\n If you don’t have Node-RED installed, follow the next tutorials:<\/p>\n\n\n\n Having Node-RED running on your Raspberry Pi, go to your Raspberry Pi IP address followed by :1880.<\/p>\n\n\n\n The Node-RED interface should open. You can simply import the final flow:<\/p>\n\n\n Go to Menu<\/strong> > Import<\/strong> and copy the following to your Clipboard to create your Node-RED flow.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n In this guide, the ESP32 performs HTTP requests to Node-RED, but you can use these examples with other services like ThingSpeak<\/a>, IFTTT.com<\/a> (WebHooks service), OpenWeatherMap.org<\/a>, PHP server<\/a>, etc… All examples presented in this guide will also work with other APIs.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n In the first example, the ESP32 will make an HTTP GET request to update a reading in a service. This type of request could also be used to filter a value, request a value, or return a JSON object.<\/p>\n\n\n After installing the necessary board add-ons and libraries, copy the following code to your Arduino IDE, but don\u2019t upload it yet. You need to make some changes to make it work for you.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Modify the next lines with your network credentials: SSID and password. The code is well commented on where you should make the changes.<\/p>\n\n\n\n You also need to type your domain name or Node-RED IP address, so the ESP publishes the readings to your own server.<\/p>\n\n\n\n Now, upload the code to your board and it should work straight away. <\/p>\n\n\n\n Read the next section, if you want to learn how to make the HTTP GET request.<\/p>\n\n\n\n In the loop()<\/span> is where you actually make the HTTP GET request every 5 seconds with sample data:<\/p>\n\n\n\n Note: if Node-RED requires authentication, uncomment the following line and insert the Node-RED username and password.<\/p>\n\n\n\n The ESP32 makes a new request in the following URL to update the sensor field with a new temperature.<\/p>\n\n\n\n Then, the following lines of code save the HTTP response from the server.<\/p>\n\n\n\n With your board running the new sketch, open the Node-RED debug window. You’ll see that the sample values are being printed successfully (24.37).<\/p>\n\n\n This next example shows how to make an HTTP GET request to get a JSON object and decode it with the ESP32. Many APIs return data in JSON format.<\/p>\n\n\n Copy the next sketch to your Arduino IDE (type your SSID and password):<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Enter your domain name or Node-RED IP address, so the ESP requests the sensor readings that will be retrieved in a JSON object.<\/p>\n\n\n\n Now, upload the code to your board.<\/p>\n\n\n\n In the loop()<\/span>, call the httpGETRequest()<\/span> function to make the HTTP GET request:<\/p>\n\n\n\n The httpGETRequest()<\/span> function makes a request to Node-RED address http:\/\/192.168.1.106:1880\/get-sensor<\/em> and it retrieves a string with a JSON object.<\/p>\n\n\n\n Note: if Node-RED requires authentication, uncomment the following line and insert the Node-RED username and password.<\/p>\n\n\n\n To get access to the values, decode the JSON object and store all values in the sensorReadingsArr<\/span> array.<\/p>\n\n\n\n After uploading the code, open the Arduino IDE and you’ll see that it’s receiving the following JSON data:<\/p>\n\n\n\n Then, you print the decoded JSON object in the Arduino IDE Serial Monitor.<\/p>\n\n\n For debugging purposes, the requested information is also printed in the Node-RED debug window.<\/p>\n\n\n Finally, you’ll learn how to make an HTTP POST request with an ESP32.<\/p>\n\n\n\n With this example, your ESP32 can make HTTP POST requests using three different types of body requests: URL encoded, JSON object or plain text. These are the most common methods and should integrate with most APIs or web services.<\/p>\n\n\n Copy the next sketch to your Arduino IDE (type your SSID and password):<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Enter your domain name or Node-RED IP address, so the ESP posts sample sensor readings.<\/p>\n\n\n\n Now, upload the code to your board.<\/p>\n\n\n\n To make an HTTP POST request of type URL encoded, like this<\/p>\n\n\n\n You need to run the following in your Arduino code:<\/p>\n\n\n\n Note: if Node-RED requires authentication, uncomment the following line and insert the Node-RED username and password.<\/p>\n\n\n\n Or if you prefer to make an HTTP POST request with a JSON object:<\/p>\n\n\n\n Use the next snippet:<\/p>\n\n\n\n If you want to send plain text or a value, use the following:<\/p>\n\n\n\n Note: <\/strong> the Node-RED flow we’re using (web service) is not setup to receive plain text, but if the API that you plan to integrate only accepts plain text or a value, you can use the previous snippet. <\/p>\n\n\n\n In the Node-RED debug window, you can view that your ESP is making an HTTP POST request every 5 seconds.<\/p>\n\n\n And in this example, those values are also sent to 3 Gauges and are displayed in Node-RED Dashboard:<\/p>\n\n\n\n In this tutorial you’ve learned how to integrate your ESP32 with online services using HTTP GET and HTTP POST requests.<\/p>\n\n\n\n HTTP GET and HTTP POST are commonly used in most web services and APIs. These can be useful in your projects to: publish your sensor readings to a web service like IFTTT, ThingSpeak; to an ESP32 or Raspberry Pi web server or to your own server; to request data from the internet or from your database, and much more.<\/p>\n\n\n\n If you’re using an ESP8266 board, read: Guide for ESP8266 NodeMCU HTTP GET and HTTP Post Requests<\/a>.<\/p>\n\n\n\n You might also like reading:<\/strong><\/p>\n\n\n\n I hope you liked this project. If you have any questions, post a comment below and we’ll try to get back to you.<\/p>\n\n\n\n If you like ESP32, you might consider enrolling in our course “Learn ESP32 with Arduino IDE<\/a>“. You can also access our free ESP32 resources here<\/a>. <\/p>\n\n\n\n Thank you for reading.<\/p>\n","protected":false},"excerpt":{"rendered":" In this guide, you’ll learn how to make HTTP GET and HTTP POST requests with the ESP32 board with Arduino IDE. We’ll cover examples on how to get values, post … <\/p>\nHTTP Request Methods: GET vs POST<\/h2>\n\n\n\n
HTTP GET<\/h3>\n\n\n\n
GET \/update-sensor?temperature=value1<\/code><\/pre>\n\n\n\nGET \/get-sensor<\/code><\/pre>\n\n\n\nHTTP POST<\/h3>\n\n\n\n
POST \/update-sensor HTTP\/1.1\nHost: example.com\napi_key=api&sensor_name=name&temperature=value1&humidity=value2&pressure=value3\nContent-Type: application\/x-www-form-urlencoded<\/code><\/pre>\n\n\n\nPOST \/update-sensor HTTP\/1.1\nHost: example.com\n{api_key: \"api\", sensor_name: \"name\", temperature: value1, humidity: value2, pressure: value3}\nContent-Type: application\/json<\/code><\/pre>\n\n\n\nHTTP GET\/POST with ESP32<\/h3>\n\n\n\n
Prerequisites<\/h2>\n\n\n\n
Arduino IDE<\/h3>\n\n\n\n
Arduino_JSON Library<\/h3>\n\n\n\n
![\"Install](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/01\/Install-Arduino-JSON-library-Arduino-IDE.png?resize=786%2C443&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nParts Required<\/h3>\n\n\n\n
![](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2017\/10\/header-200.png?w=1200&quality=100&strip=all&ssl=1\")
<\/a><\/p>\n\n\n\nPreparing Node-RED (optional)<\/h3>\n\n\n\n
http://raspberry-pi-ip-address:1880<\/code><\/pre>\n\n\n\n![\"Node-RED-Flow-HTTP-GET-POST-Request-Methods-ESP32-ESP8266-Arduino\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/Node-RED-Flow-HTTP-GET-POST-Request-Methods-ESP32-ESP8266-Arduino.png?resize=854%2C566&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n[{"id":"599740b7.efde9","type":"http response","z":"b01416d3.f69f38","name":"","statusCode":"200","headers":{},"x":420,"y":689,"wires":[]},{"id":"1618a829.76f638","type":"json","z":"b01416d3.f69f38","name":"","property":"payload","action":"obj","pretty":true,"x":410,"y":809,"wires":[["d0089cc7.d25ac"]]},{"id":"c7410fa2.1c2fa","type":"debug","z":"b01416d3.f69f38","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":850,"y":709,"wires":[]},{"id":"75a22f74.f1aba","type":"ui_text","z":"b01416d3.f69f38","group":"2b7ac01b.fc984","order":1,"width":0,"height":0,"name":"","label":"Sensor Name","format":"{{msg.payload}}","layout":"row-spread","x":860,"y":769,"wires":[]},{"id":"1c8f9093.8bc2bf","type":"ui_gauge","z":"b01416d3.f69f38","name":"","group":"2b7ac01b.fc984","order":2,"width":0,"height":0,"gtype":"gage","title":"Temperature","label":"\u00baC","format":"{{value}}","min":0,"max":"38","colors":["#00b500","#e6e600","#ca3838"],"seg1":"","seg2":"","x":850,"y":829,"wires":[]},{"id":"a5bd2706.54e108","type":"ui_gauge","z":"b01416d3.f69f38","name":"","group":"2b7ac01b.fc984","order":3,"width":0,"height":0,"gtype":"gage","title":"Humidity","label":"%","format":"{{value}}","min":0,"max":"100","colors":["#0080ff","#0062c4","#002f5e"],"seg1":"","seg2":"","x":840,"y":889,"wires":[]},{"id":"105ac2cc.7b3cfd","type":"ui_gauge","z":"b01416d3.f69f38","name":"","group":"2b7ac01b.fc984","order":4,"width":0,"height":0,"gtype":"gage","title":"Pressure","label":"hPa","format":"{{value}}","min":0,"max":"1200","colors":["#b366ff","#8000ff","#440088"],"seg1":"","seg2":"","x":840,"y":949,"wires":[]},{"id":"d0089cc7.d25ac","type":"function","z":"b01416d3.f69f38","name":"JSON or URL Encoded","func":"var msg0 = { payload: msg.payload.api_key };\\nvar msg1 = { payload: msg.payload.sensor };\\nvar msg2 = { payload: msg.payload.value1 };\\nvar msg3 = { payload: msg.payload.value2 };\\nvar msg4 = { payload: msg.payload.value3 };\\n\\nreturn [msg0, msg1, msg2, msg3, msg4];","outputs":5,"noerr":0,"x":610,"y":809,"wires":[["c7410fa2.1c2fa"],["75a22f74.f1aba"],["1c8f9093.8bc2bf"],["a5bd2706.54e108"],["105ac2cc.7b3cfd"]]},{"id":"5d9ab0d2.66b92","type":"http in","z":"b01416d3.f69f38","name":"","url":"update-sensor","method":"post","upload":false,"swaggerDoc":"","x":200,"y":740,"wires":[["599740b7.efde9","c7410fa2.1c2fa","1618a829.76f638"]]},{"id":"7f5cf345.63f56c","type":"http response","z":"b01416d3.f69f38","name":"","statusCode":"200","headers":{},"x":540,"y":420,"wires":[]},{"id":"6530621.95b429c","type":"http in","z":"b01416d3.f69f38","name":"","url":"\/get-sensor","method":"get","upload":false,"swaggerDoc":"","x":180,"y":600,"wires":[["9471d1a0.68588"]]},{"id":"5ddc9f47.4b555","type":"http response","z":"b01416d3.f69f38","name":"","statusCode":"200","headers":{},"x":540,"y":560,"wires":[]},{"id":"9471d1a0.68588","type":"function","z":"b01416d3.f69f38","name":"","func":"msg.payload = {\\"value1\\":24.25, \\"value2\\":49.54, \\"value3\\":1005.14};\\nreturn msg;","outputs":1,"noerr":0,"x":350,"y":600,"wires":[["5ddc9f47.4b555","13aea59.7430e5a"]]},{"id":"13aea59.7430e5a","type":"debug","z":"b01416d3.f69f38","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":550,"y":628,"wires":[]},{"id":"e71c7a7d.e7c598","type":"debug","z":"b01416d3.f69f38","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":550,"y":500,"wires":[]},{"id":"c7807102.3f433","type":"http in","z":"b01416d3.f69f38","name":"","url":"\/update-sensor","method":"get","upload":false,"swaggerDoc":"","x":190,"y":460,"wires":[["60410cde.562a34"]]},{"id":"60410cde.562a34","type":"function","z":"b01416d3.f69f38","name":"","func":"msg.payload = msg.payload.temperature;\\nreturn msg;","outputs":1,"noerr":0,"x":390,"y":460,"wires":[["e71c7a7d.e7c598","7f5cf345.63f56c"]]},{"id":"2b7ac01b.fc984","type":"ui_group","z":"","name":"SENSORS","tab":"99ab8dc5.f435c","disp":true,"width":"6","collapse":false},{"id":"99ab8dc5.f435c","type":"ui_tab","z":"","name":"HTTP","icon":"dashboard","order":1,"disabled":false,"hidden":false}]\n<\/code><\/pre>\n\tOther Web Services or APIs<\/h3>\n\n\n\n
1. ESP32 HTTP GET: Value or Query in URL<\/h2>\n\n\n\n
![\"HTTP](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/HTTP-GET-ESP32-Get-Sensor-Value-Plain-Text-OK.png?resize=900%2C426&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nCode ESP32 HTTP GET with Arduino IDE<\/h3>\n\n\n\n
\/*\r\n Rui Santos\r\n Complete project details at Complete project details at https:\/\/RandomNerdTutorials.com\/esp32-http-get-post-arduino\/\r\n\r\n Permission is hereby granted, free of charge, to any person obtaining a copy\r\n of this software and associated documentation files.\r\n\r\n The above copyright notice and this permission notice shall be included in all\r\n copies or substantial portions of the Software.\r\n*\/\r\n\r\n#include <WiFi.h>\r\n#include <HTTPClient.h>\r\n\r\nconst char* ssid = "REPLACE_WITH_YOUR_SSID";\r\nconst char* password = "REPLACE_WITH_YOUR_PASSWORD";\r\n\r\n\/\/Your Domain name with URL path or IP address with path\r\nString serverName = "http:\/\/192.168.1.106:1880\/update-sensor";\r\n\r\n\/\/ the following variables are unsigned longs because the time, measured in\r\n\/\/ milliseconds, will quickly become a bigger number than can be stored in an int.\r\nunsigned long lastTime = 0;\r\n\/\/ Timer set to 10 minutes (600000)\r\n\/\/unsigned long timerDelay = 600000;\r\n\/\/ Set timer to 5 seconds (5000)\r\nunsigned long timerDelay = 5000;\r\n\r\nvoid setup() {\r\n Serial.begin(115200); \r\n\r\n WiFi.begin(ssid, password);\r\n Serial.println("Connecting");\r\n while(WiFi.status() != WL_CONNECTED) {\r\n delay(500);\r\n Serial.print(".");\r\n }\r\n Serial.println("");\r\n Serial.print("Connected to WiFi network with IP Address: ");\r\n Serial.println(WiFi.localIP());\r\n \r\n Serial.println("Timer set to 5 seconds (timerDelay variable), it will take 5 seconds before publishing the first reading.");\r\n}\r\n\r\nvoid loop() {\r\n \/\/Send an HTTP POST request every 10 minutes\r\n if ((millis() - lastTime) > timerDelay) {\r\n \/\/Check WiFi connection status\r\n if(WiFi.status()== WL_CONNECTED){\r\n HTTPClient http;\r\n\r\n String serverPath = serverName + "?temperature=24.37";\r\n \r\n \/\/ Your Domain name with URL path or IP address with path\r\n http.begin(serverPath.c_str());\r\n \r\n \/\/ If you need Node-RED\/server authentication, insert user and password below\r\n \/\/http.setAuthorization("REPLACE_WITH_SERVER_USERNAME", "REPLACE_WITH_SERVER_PASSWORD");\r\n \r\n \/\/ Send HTTP GET request\r\n int httpResponseCode = http.GET();\r\n \r\n if (httpResponseCode>0) {\r\n Serial.print("HTTP Response code: ");\r\n Serial.println(httpResponseCode);\r\n String payload = http.getString();\r\n Serial.println(payload);\r\n }\r\n else {\r\n Serial.print("Error code: ");\r\n Serial.println(httpResponseCode);\r\n }\r\n \/\/ Free resources\r\n http.end();\r\n }\r\n else {\r\n Serial.println("WiFi Disconnected");\r\n }\r\n lastTime = millis();\r\n }\r\n}\r\n<\/code><\/pre>\n\tSetting your network credentials<\/h4>\n\n\n\n
\/\/ Replace with your network credentials\nconst char* ssid = \"REPLACE_WITH_YOUR_SSID\";\nconst char* password = \"REPLACE_WITH_YOUR_PASSWORD\";<\/code><\/pre>\n\n\n\nSetting your serverName<\/h4>\n\n\n\n
String serverName = \"http:\/\/192.168.1.106:1880\/update-sensor\";<\/code><\/pre>\n\n\n\nHTTP GET Request<\/h4>\n\n\n\n
String serverPath = serverName + \"?temperature=24.37\";\n\n\/\/ Your Domain name with URL path or IP address with path\nhttp.begin(serverPath.c_str());\n\n\/\/ If your need Node-RED\/server authentication, insert user and password below\n\/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");\n\n\/\/ Send HTTP GET request\nint httpResponseCode = http.GET();<\/code><\/pre>\n\n\n\n\/\/ If you need Node-RED\/server authentication, insert user and password below\n\/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");<\/code><\/pre>\n\n\n\nhttp://192.168.1.106:1880\/update-sensor?temperature=24.37<\/code><\/pre>\n\n\n\nif (httpResponseCode>0) {\n Serial.print(\"HTTP Response code: \");\n Serial.println(httpResponseCode);\n String payload = http.getString();\n Serial.println(payload);\n}\nelse {\n Serial.print(\"Error code: \");\n Serial.println(httpResponseCode);\n}<\/code><\/pre>\n\n\n\nDemonstration<\/h3>\n\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/udpate-data-esp32-HTTP-GET-ESP8266-NodeMCU-Arduino-value.png?resize=302%2C220&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n2. ESP32 HTTP GET: JSON Data Object or Plain Text<\/h2>\n\n\n\n
![\"HTTP](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/HTTP-GET-ESP32-Get-Sensor-JSON-Data.png?resize=900%2C426&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\/*\r\n Rui Santos\r\n Complete project details at Complete project details at https:\/\/RandomNerdTutorials.com\/esp32-http-get-post-arduino\/\r\n\r\n Permission is hereby granted, free of charge, to any person obtaining a copy\r\n of this software and associated documentation files.\r\n\r\n The above copyright notice and this permission notice shall be included in all\r\n copies or substantial portions of the Software.\r\n*\/\r\n\r\n#include <WiFi.h>\r\n#include <HTTPClient.h>\r\n#include <Arduino_JSON.h>\r\n\r\nconst char* ssid = "REPLACE_WITH_YOUR_SSID";\r\nconst char* password = "REPLACE_WITH_YOUR_PASSWORD";\r\n\r\n\/\/Your Domain name with URL path or IP address with path\r\nconst char* serverName = "http:\/\/192.168.1.106:1880\/get-sensor";\r\n\r\n\/\/ the following variables are unsigned longs because the time, measured in\r\n\/\/ milliseconds, will quickly become a bigger number than can be stored in an int.\r\nunsigned long lastTime = 0;\r\n\/\/ Timer set to 10 minutes (600000)\r\n\/\/unsigned long timerDelay = 600000;\r\n\/\/ Set timer to 5 seconds (5000)\r\nunsigned long timerDelay = 5000;\r\n\r\nString sensorReadings;\r\nfloat sensorReadingsArr[3];\r\n\r\nvoid setup() {\r\n Serial.begin(115200);\r\n\r\n WiFi.begin(ssid, password);\r\n Serial.println("Connecting");\r\n while(WiFi.status() != WL_CONNECTED) {\r\n delay(500);\r\n Serial.print(".");\r\n }\r\n Serial.println("");\r\n Serial.print("Connected to WiFi network with IP Address: ");\r\n Serial.println(WiFi.localIP());\r\n \r\n Serial.println("Timer set to 5 seconds (timerDelay variable), it will take 5 seconds before publishing the first reading.");\r\n}\r\n\r\nvoid loop() {\r\n \/\/Send an HTTP POST request every 10 minutes\r\n if ((millis() - lastTime) > timerDelay) {\r\n \/\/Check WiFi connection status\r\n if(WiFi.status()== WL_CONNECTED){\r\n \r\n sensorReadings = httpGETRequest(serverName);\r\n Serial.println(sensorReadings);\r\n JSONVar myObject = JSON.parse(sensorReadings);\r\n \r\n \/\/ JSON.typeof(jsonVar) can be used to get the type of the var\r\n if (JSON.typeof(myObject) == "undefined") {\r\n Serial.println("Parsing input failed!");\r\n return;\r\n }\r\n \r\n Serial.print("JSON object = ");\r\n Serial.println(myObject);\r\n \r\n \/\/ myObject.keys() can be used to get an array of all the keys in the object\r\n JSONVar keys = myObject.keys();\r\n \r\n for (int i = 0; i < keys.length(); i++) {\r\n JSONVar value = myObject[keys[i]];\r\n Serial.print(keys[i]);\r\n Serial.print(" = ");\r\n Serial.println(value);\r\n sensorReadingsArr[i] = double(value);\r\n }\r\n Serial.print("1 = ");\r\n Serial.println(sensorReadingsArr[0]);\r\n Serial.print("2 = ");\r\n Serial.println(sensorReadingsArr[1]);\r\n Serial.print("3 = ");\r\n Serial.println(sensorReadingsArr[2]);\r\n }\r\n else {\r\n Serial.println("WiFi Disconnected");\r\n }\r\n lastTime = millis();\r\n }\r\n}\r\n\r\nString httpGETRequest(const char* serverName) {\r\n WiFiClient client;\r\n HTTPClient http;\r\n \r\n \/\/ Your Domain name with URL path or IP address with path\r\n http.begin(client, serverName);\r\n \r\n \/\/ If you need Node-RED\/server authentication, insert user and password below\r\n \/\/http.setAuthorization("REPLACE_WITH_SERVER_USERNAME", "REPLACE_WITH_SERVER_PASSWORD");\r\n \r\n \/\/ Send HTTP POST request\r\n int httpResponseCode = http.GET();\r\n \r\n String payload = "{}"; \r\n \r\n if (httpResponseCode>0) {\r\n Serial.print("HTTP Response code: ");\r\n Serial.println(httpResponseCode);\r\n payload = http.getString();\r\n }\r\n else {\r\n Serial.print("Error code: ");\r\n Serial.println(httpResponseCode);\r\n }\r\n \/\/ Free resources\r\n http.end();\r\n\r\n return payload;\r\n}\r\n<\/code><\/pre>\n\tSetting your serverName<\/h3>\n\n\n\n
String serverName = \"http:\/\/192.168.1.106:1880\/get-sensor\";<\/code><\/pre>\n\n\n\nHTTP GET Request (JSON Object)<\/h3>\n\n\n\n
sensorReadings = httpGETRequest(serverName);<\/code><\/pre>\n\n\n\nString httpGETRequest(const char* serverName) {\n HTTPClient http;\n\n \/\/ Your IP address with path or Domain name with URL path \n http.begin(serverName);\n\n \/\/ If you need Node-RED\/server authentication, insert user and password below\n \/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");\n\n\n \/\/ Send HTTP POST request\n int httpResponseCode = http.GET();\n\n String payload = \"{}\"; \n\n if (httpResponseCode>0) {\n Serial.print(\"HTTP Response code: \");\n Serial.println(httpResponseCode);\n payload = http.getString();\n }\n else {\n Serial.print(\"Error code: \");\n Serial.println(httpResponseCode);\n }\n \/\/ Free resources\n http.end();\n\n return payload;\n}<\/code><\/pre>\n\n\n\n\/\/ If you need Node-RED\/server authentication, insert user and password below\n\/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");<\/code><\/pre>\n\n\n\nDecoding JSON Object<\/h3>\n\n\n\n
JSONVar myObject = JSON.parse(sensorReadings);\n\n\/\/ JSON.typeof(jsonVar) can be used to get the type of the var\nif (JSON.typeof(myObject) == \"undefined\") {\n Serial.println(\"Parsing input failed!\");\n return;\n}\n\nSerial.print(\"JSON object = \");\nSerial.println(myObject);\n\n\/\/ myObject.keys() can be used to get an array of all the keys in the object\nJSONVar keys = myObject.keys();\n\nfor (int i = 0; i < keys.length(); i++) {\n JSONVar value = myObject[keys[i]];\n Serial.print(keys[i]);\n Serial.print(\" = \");\n Serial.println(value);\n sensorReadingsArr[i] = double(value);\n}\nSerial.print(\"1 = \");\nSerial.println(sensorReadingsArr[0]);\nSerial.print(\"2 = \");\nSerial.println(sensorReadingsArr[1]);\nSerial.print(\"3 = \");\nSerial.println(sensorReadingsArr[2]);<\/code><\/pre>\n\n\n\nHTTP GET Demonstration<\/h3>\n\n\n\n
{\"value1\":24.25,\"value2\":49.54,\"value3\":1005.14}<\/code><\/pre>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/JSON-Data-object-HTTP-POST-Request-Method.png?resize=859%2C396&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/udpate-data-esp32-HTTP-GET-ESP8266-NodeMCU-Arduino-JSON-object.png?resize=434%2C221&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n3. ESP32 HTTP POST: URL Encoded, JSON Data Object, Plain Text<\/h2>\n\n\n\n
![\"HTTP](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/HTTP-POST-ESP32-URL-Encoded-JSON-Object-Data-Plain-Text.png?resize=900%2C426&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\/*\r\n Rui Santos\r\n Complete project details at Complete project details at https:\/\/RandomNerdTutorials.com\/esp32-http-get-post-arduino\/\r\n\r\n Permission is hereby granted, free of charge, to any person obtaining a copy\r\n of this software and associated documentation files.\r\n\r\n The above copyright notice and this permission notice shall be included in all\r\n copies or substantial portions of the Software.\r\n*\/\r\n\r\n#include <WiFi.h>\r\n#include <HTTPClient.h>\r\n\r\nconst char* ssid = "REPLACE_WITH_YOUR_SSID";\r\nconst char* password = "REPLACE_WITH_YOUR_PASSWORD";\r\n\r\n\/\/Your Domain name with URL path or IP address with path\r\nconst char* serverName = "http:\/\/192.168.1.106:1880\/update-sensor";\r\n\r\n\/\/ the following variables are unsigned longs because the time, measured in\r\n\/\/ milliseconds, will quickly become a bigger number than can be stored in an int.\r\nunsigned long lastTime = 0;\r\n\/\/ Timer set to 10 minutes (600000)\r\n\/\/unsigned long timerDelay = 600000;\r\n\/\/ Set timer to 5 seconds (5000)\r\nunsigned long timerDelay = 5000;\r\n\r\nvoid setup() {\r\n Serial.begin(115200);\r\n\r\n WiFi.begin(ssid, password);\r\n Serial.println("Connecting");\r\n while(WiFi.status() != WL_CONNECTED) {\r\n delay(500);\r\n Serial.print(".");\r\n }\r\n Serial.println("");\r\n Serial.print("Connected to WiFi network with IP Address: ");\r\n Serial.println(WiFi.localIP());\r\n \r\n Serial.println("Timer set to 5 seconds (timerDelay variable), it will take 5 seconds before publishing the first reading.");\r\n}\r\n\r\nvoid loop() {\r\n \/\/Send an HTTP POST request every 10 minutes\r\n if ((millis() - lastTime) > timerDelay) {\r\n \/\/Check WiFi connection status\r\n if(WiFi.status()== WL_CONNECTED){\r\n WiFiClient client;\r\n HTTPClient http;\r\n \r\n \/\/ Your Domain name with URL path or IP address with path\r\n http.begin(client, serverName);\r\n \r\n \/\/ If you need Node-RED\/server authentication, insert user and password below\r\n \/\/http.setAuthorization("REPLACE_WITH_SERVER_USERNAME", "REPLACE_WITH_SERVER_PASSWORD");\r\n \r\n \/\/ Specify content-type header\r\n http.addHeader("Content-Type", "application\/x-www-form-urlencoded");\r\n \/\/ Data to send with HTTP POST\r\n String httpRequestData = "api_key=tPmAT5Ab3j7F9&sensor=BME280&value1=24.25&value2=49.54&value3=1005.14"; \r\n \/\/ Send HTTP POST request\r\n int httpResponseCode = http.POST(httpRequestData);\r\n \r\n \/\/ If you need an HTTP request with a content type: application\/json, use the following:\r\n \/\/http.addHeader("Content-Type", "application\/json");\r\n \/\/int httpResponseCode = http.POST("{\\"api_key\\":\\"tPmAT5Ab3j7F9\\",\\"sensor\\":\\"BME280\\",\\"value1\\":\\"24.25\\",\\"value2\\":\\"49.54\\",\\"value3\\":\\"1005.14\\"}");\r\n\r\n \/\/ If you need an HTTP request with a content type: text\/plain\r\n \/\/http.addHeader("Content-Type", "text\/plain");\r\n \/\/int httpResponseCode = http.POST("Hello, World!");\r\n \r\n Serial.print("HTTP Response code: ");\r\n Serial.println(httpResponseCode);\r\n \r\n \/\/ Free resources\r\n http.end();\r\n }\r\n else {\r\n Serial.println("WiFi Disconnected");\r\n }\r\n lastTime = millis();\r\n }\r\n}\r\n<\/code><\/pre>\n\tSetting your serverName<\/h3>\n\n\n\n
String serverName = \"http:\/\/192.168.1.106:1880\/update-sensor\";<\/code><\/pre>\n\n\n\nHTTP POST URL Encoded<\/h3>\n\n\n\n
POST \/update-sensor HTTP\/1.1\nHost: 192.168.1.106:1880\napi_key=tPmAT5Ab3j7F9&sensor=BME280&value1=24.25&value2=49.54&value3=1005.14\nContent-Type: application\/x-www-form-urlencoded<\/code><\/pre>\n\n\n\n\/\/ Your Domain name with URL path or IP address with path\nhttp.begin(serverName);\n\n\/\/ If you need Node-RED\/server authentication, insert user and password below\r\n\/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");\n\n\/\/ Specify content-type header\nhttp.addHeader(\"Content-Type\", \"application\/x-www-form-urlencoded\");\n\n\/\/ Data to send with HTTP POST\nString httpRequestData = \"api_key=tPmAT5Ab3j7F9&sensor=BME280&value1=24.25&value2=49.54&value3=1005.14\";\n\n\/\/ Send HTTP POST request\nint httpResponseCode = http.POST(httpRequestData);<\/code><\/pre>\n\n\n\n\/\/ If you need Node-RED\/server authentication, insert user and password below\n\/\/http.setAuthorization(\"REPLACE_WITH_SERVER_USERNAME\", \"REPLACE_WITH_SERVER_PASSWORD\");<\/code><\/pre>\n\n\n\nHTTP POST JSON Object<\/h3>\n\n\n\n
POST \/update-sensor HTTP\/1.1\nHost: example.com\n{api_key: \"tPmAT5Ab3j7F9\", sensor_name: \"BME280\", temperature: 24.25; humidity: 49.54; pressure: 1005.14}\nContent-Type: application\/json<\/code><\/pre>\n\n\n\nhttp.addHeader(\"Content-Type\", \"application\/json\");\n\nint httpResponseCode = http.POST(\"{\\\"api_key\\\":\\\"tPmAT5Ab3j7F9\\\",\\\"sensor\\\":\\\"BME280\\\",\\\"value1\\\":\\\"24.25\\\",\\\"value2\\\":\\\"49.54\\\",\\\"value3\\\":\\\"1005.14\\\"}\");<\/code><\/pre>\n\n\n\nHTTP Plain Text<\/h3>\n\n\n\n
http.addHeader(\"Content-Type\", \"text\/plain\");\n\nint httpResponseCode = http.POST(\"Hello, World!\");<\/code><\/pre>\n\n\n\nHTTP POST Demonstration<\/h3>\n\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/udpate-data-esp32-HTTP-POST-ESP8266-NodeMCU-Arduino-value.png?resize=439%2C236&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nhttp://raspberry-pi-ip-address:1880\/ui<\/code><\/pre>\n\n\n![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/04\/ESP32-ESP8266-HTTP-GET-POST-Demonstration.png?resize=518%2C806&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nWrapping Up<\/h2>\n\n\n\n