ESP32Express Starter Sketch for PlatformIO

This repository provides a basic sketch for ESP32 using the esp32express library. It is designed as a quick start template for controlling hardware resources (e.g., LEDs, relays, sensors) and setting up a simple web server.

Features

• Easy-to-use esp32express library for handling Wi-Fi and web server interactions.
• Basic API endpoints to control hardware and retrieve device information:
  • /ping: Returns the device's IP address and free heap size in JSON format.
  • /on: Activates a connected hardware resource and returns updated device information.
  • /off: Deactivates the hardware resource and returns updated device information.
• Built-in JSON support using ArduinoJson.
• Simplified Wi-Fi configuration and connection management.
• Ready-to-use template for various IoT applications.

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Requirements

• Hardware: ESP32 microcontroller with any GPIO-controlled hardware (e.g., LEDs, relays, actuators).
• Software: PlatformIO IDE or Arduino IDE.
• Libraries:
  • esp32express
  • ArduinoJson

You can install these libraries via PlatformIO's lib_deps configuration.

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Getting Started

1. Clone this repository:

git clone https://github.com/Dewo72d/ESP32Express-Starter-Sketch-for-PlatformIO

2. Set up PlatformIO

Ensure you have PlatformIO installed. Add the required libraries to your platformio.ini file:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
upload_speed = 115200
monitor_speed = 115200
lib_deps = bblanchon/ArduinoJson@^7.2.1
upload_protocol = esptool

3. Update Wi-Fi Credentials

Replace the placeholders in ssid and password variables in the sketch with your Wi-Fi network credentials:

const char *ssid = "your-ssid";
const char *password = "your-password";

4. Customize GPIO Pin

Update the RESOURCE_PIN definition in the sketch to match the GPIO pin connected to your hardware resource:

#define RESOURCE_PIN 4  // Change 4 to the pin connected to your device

5. Build and Upload

Compile and upload the sketch to your ESP32 device using PlatformIO:

pio run --target upload

6. Open Serial Monitor

Monitor your device's output for Wi-Fi connection status and IP address:

pio device monitor

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API Endpoints

/ping

• Description: Returns the device's IP address and free heap memory.
• Method: GET
• Response: JSON

{
  "ip": "192.168.0.20",
  "heap": "123456"
}

/on

• Description: Activates the connected resource (e.g., turns on an LED, powers a relay).
• Method: GET
• Response: JSON

{
  "ip": "192.168.0.20",
  "heap": "123456"
}

/off

• Description: Deactivates the connected resource (e.g., turns off an LED, disables a relay).
• Method: GET
• Response: JSON

{
  "ip": "192.168.0.20",
  "heap": "123456"
}

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Code Overview

Key Components

• esp32express Library: Handles Wi-Fi connections and simplifies HTTP server setup.

• ArduinoJson: Used for creating and serializing JSON responses.

Sketch Details

1. Wi-Fi Initialization: The Esp32express library handles Wi-Fi configuration and connects using the provided credentials.

2. Web Server Endpoints:

   • The server is initialized on port 3000.
   • Handlers for /ping, /on, and /off provide basic device controls and feedback.

3. Device Information: The get_json_data() function collects and serializes the device's IP and heap size.

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Usage Example

1. Connect your ESP32 to the same Wi-Fi network as your computer.
2. Access the device's API endpoints using a browser or tools like curl or Postman.

Example curl requests:

curl http://<device-ip>:3000/ping
curl http://<device-ip>:3000/on
curl http://<device-ip>:3000/off

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Extending the Project

• Add More Endpoints: Use the server.on() method to define new routes for interacting with additional devices or sensors.
• Control Multiple Resources: Add more GPIO pins and map them to specific API endpoints.
• Expand JSON Responses: Include more device information (e.g., uptime, sensor readings) in the get_json_data() function.