Required Libraries¶

Libraries required for the IoT Toolkit.

Core Libraries¶

WiFi (Built-in)¶

#include <WiFi.h>

- Source: Included with ESP32 board support - Purpose: WiFi connectivity - Required: Yes

Wire (Built-in)¶

#include <Wire.h>

- Source: Arduino core - Purpose: I2C communication - Required: Yes

SPI (Built-in)¶

#include <SPI.h>

- Source: Arduino core - Purpose: SPI communication - Required: Yes (for TFT display)

Sensor Libraries¶

DHT Sensor (Temp/Humidity)¶

#include "DHT.h"

- Install: Arduino Library Manager - Search: "DHT sensor library" (by Adafruit) - Dependency: Also install "Adafruit Unified Sensor" if prompted.

Vibration/Accelerometer¶

// For MPU6050 (Recommended)
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>

// For ADXL335 (Analog)
// No specific library required; use analogRead().

- Install: Arduino Library Manager - Search: "Adafruit MPU6050"

Acoustic Sensor¶

// TODO: Add library name
#include <???.h>

- Install: Arduino Library Manager - Search:

Display Libraries¶

LCD (I2C)¶

#include <LiquidCrystal_I2C.h>

- Install: Arduino Library Manager - Search: "LiquidCrystal I2C" - Author: Frank de Brabander - Purpose: I2C LCD control

TFT Display¶

// TODO: Add specific library
#include <???.h>

Options: - Adafruit_ST7735 - for ST7735-based displays - Adafruit_ILI9341 - for ILI9341-based displays - TFT_eSPI - Universal TFT library (recommended)

Install TFT_eSPI: 1. Arduino Library Manager 2. Search: "TFT_eSPI" 3. Author: Bodmer 4. Click Install

Communication Libraries¶

MQTT¶

#include <PubSubClient.h>

- Install: Arduino Library Manager - Search: "PubSubClient" - Author: Nick O'Leary - Purpose: MQTT client

HTTP¶

Built-in with ESP32:

#include <HTTPClient.h>

CoAP¶

#include <coap-simple.h>

- Install: Arduino Library Manager - Search: "coap-simple" - Purpose: CoAP client

WiFiClientSecure (for TLS)¶

#include <WiFiClientSecure.h>

- Source: Built-in with ESP32

JSON Processing¶

ArduinoJson¶

#include <ArduinoJson.h>

- Install: Arduino Library Manager - Search: "ArduinoJson" - Author: Benoit Blanchon - Version: 6.x recommended - Purpose: JSON encoding/decoding

Installation Guide¶

Method 1: Library Manager (Recommended)¶

Open Arduino IDE
Go to Sketch > Include Library > Manage Libraries
Search for library name
Select library and version
Click Install

Method 2: ZIP File¶

Download library as ZIP
Arduino IDE: Sketch > Include Library > Add .ZIP Library
Select downloaded ZIP file

Method 3: Manual Installation¶

Download and extract library
Copy to Arduino libraries folder:
Windows: Documents\Arduino\libraries\
macOS: ~/Documents/Arduino/libraries/
Linux: ~/Arduino/libraries/
Restart Arduino IDE

Library Verification¶

Check Installed Libraries¶

Arduino IDE: Sketch > Include Library

Or check libraries folder:

Documents/Arduino/libraries/
├── Adafruit_GFX_Library
├── ArduinoJson
├── LiquidCrystal_I2C
├── PubSubClient
├── TFT_eSPI
└── ...

Test Include¶

Create a test sketch:

// Test all includes
#include <WiFi.h>
#include <Wire.h>
#include <SPI.h>
#include <LiquidCrystal_I2C.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

void setup() {
  Serial.begin(115200);
  Serial.println("All libraries loaded successfully!");
}

void loop() {
  // Empty
}

Compile (Ctrl+R) to verify all libraries are found.

Complete Library List¶

Library	Version	Required	Install Source
WiFi	Built-in	Yes	ESP32 core
Wire	Built-in	Yes	ESP32 core
SPI	Built-in	Yes	ESP32 core
HTTPClient	Built-in	Yes	ESP32 core
WiFiClientSecure	Built-in	Optional	ESP32 core
LiquidCrystal_I2C	Latest	Yes	Library Manager
TFT_eSPI	Latest	Yes	Library Manager
PubSubClient	Latest	Yes (MQTT)	Library Manager
ArduinoJson	6.x	Recommended	Library Manager

Troubleshooting¶

Issue	Solution
Library not found	Verify correct name, check installation
Version conflict	Install specific version via Library Manager
Multiple versions	Remove old versions from libraries folder
Compilation errors	Update to latest library version