ESP32 HTTPClient Library – POST

/*
 * Author: Avant Maker
 * Date: February 21, 2025
 * Version: 1.0
 * Description: This example code demonstrates how to 
 * use the ESP32 HTTPClient Library's POST to send data 
 * to https://httpbin.org/post. 
 * The httpbin.org service is a free tool designed for testing 
 * HTTP requests—it accepts your POST data and responds with a
 * JSON object containing what you sent. 
 *
 * License: MIT 
 * 
 * Code Source: This example code is sourced from the Comprehensive 
 * Guide to the ESP32 Arduino Core Library, accessible on 
 * AvantMaker.com. For additional code examples and in-depth 
 * documentation related to the ESP32 Arduino Core Library, 
 * please visit:
 *
 * https://avantmaker.com/references/esp32-arduino-core-index/
 *
 * AvantMaker.com, your premier destination for all things 
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated 
 * to empowering makers, learners, and enthusiasts with the resources
 * they need to bring their innovative ideas to life.
 */

#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";

void setup() {
    Serial.begin(115200);
    WiFi.begin(ssid, password);

    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("Connected to WiFi");
}

void loop() {
    if (WiFi.status() == WL_CONNECTED) {
        HTTPClient http;
        http.begin("https://httpbin.org/post"); // Real public endpoint
        http.addHeader("Content-Type", "application/x-www-form-urlencoded");

        // Simple key-value data to send
        String postData = "device=ESP32&user=AvantMaker";
        int httpCode = http.POST(postData);

        if (httpCode > 0) {
            Serial.printf("HTTP Response Code: %d\n", httpCode);
            if (httpCode == HTTP_CODE_OK) { // 200
                String response = http.getString();
                Serial.println("Server Response:");
                Serial.println(response);
            }
        } else {
            Serial.printf("POST failed, error: %s\n", http.errorToString(httpCode).c_str());
        }
        http.end();
    }
    delay(20000); // Send POST every 20 seconds
}

/*
 * Author: Avant Maker
 * Date: February 21, 2025
 * Version: 1.0
 * Description: This example code demonstrates how to 
 * use the ESP32 HTTPClient Library's POST to send a 
 * payload as a byte array (uint8_t *) with a specified
 * size, which is ideal for transmitting raw binary 
 * data or non-string payloads. 
 *
 * License: MIT 
 * 
 * Code Source: This example code is sourced from the Comprehensive 
 * Guide to the ESP32 Arduino Core Library, accessible on 
 * AvantMaker.com. For additional code examples and in-depth 
 * documentation related to the ESP32 Arduino Core Library, 
 * please visit:
 *
 * https://avantmaker.com/references/esp32-arduino-core-index/
 *
 * AvantMaker.com, your premier destination for all things 
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated 
 * to empowering makers, learners, and enthusiasts with the resources
 * they need to bring their innovative ideas to life.
 */

#include <WiFi.h>
#include <HTTPClient.h>

// WiFi credentials
const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";

void setup() {
    Serial.begin(115200);

    // Connect to WiFi
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("Connected to WiFi");

    // Initialize HTTPClient
    HTTPClient http;

    // Specify the URL
    http.begin("https://httpbin.org/post");

    // Set content type header (optional, depending on payload type)
    http.addHeader("Content-Type", "application/octet-stream");

    // Define the payload as a byte array
    uint8_t payload[] = {0x50, 0x6F, 0x73, 0x74, 0x20, 0x66, 0x72, 0x6F, 0x6D, 0x20, 0x45, 0x53, 0x50, 0x33, 0x32}; // "Post from ESP32" in ASCII
    size_t payloadSize = sizeof(payload);

    // Send POST request with byte array payload
    int httpCode = http.POST(payload, payloadSize);

    // Check the response
    if (httpCode > 0) {
        Serial.printf("POST request succeeded with code: %d\n", httpCode);
        String response = http.getString();
        Serial.println("Server response: " + response);
    } else {
        Serial.printf("POST request failed, error: %s\n", http.errorToString(httpCode).c_str());
    }

    // End the connection
    http.end();
}

void loop() {
    // Do nothing in loop
}