# ESP32 MQTT Client Examples

In this example we provide sample code for TCP protocol connection to the MQTT Broker. For more documentation on using the ESP32 MQTT client, see the [Pubsubclient Documentation](https://pubsubclient.knolleary.net/).

## Prerequisites

* Arduino ESP32 development board management address: https://dl.espressif.com/dl/package_esp32_index.json

## Arduino settings

* Installing the ESP32 Board

```
Tools -> Board -> Boards Manager... -> -> Type ESP32 in Search field -> Install
```

* Installing the PubSubClient Library

```bash
Sketch -> Include Library -> Manage Libraries... -> Type PubSubClient in Search field -> Install PubSubClient by Nick O’Leary
```

## Ino File

* esp32_connect_mqtt.ino: ESP32 connects to the MQTT broker
* esp32_connect_mqtt_via_tls.ino: ESP32 connects to the MQTT broker via TLS
* esp32_DS18B20_temp_chart: ESP32 connects to the MQTT broker and uploads DS18B20 temperature sensor data, while displaying the temperature chart in real time
* esp32_DS18B20_sensor_via_tls.ino: ESP32 connects to the MQTT broker via TLS and uploads DS18B20 temperature sensor data
* esp32_soil_moisture_sensor_via_tls.ino: ESP32 connects to the MQTT broker via TLS and uploads soil moisture sensor data

## TLS Config

For TLS connection example code, the default includes DigiCert Global Root G2 (broker.emqx.io.crt) and DigiCert Global Root CA (emqxsl-ca.crt) ca_cert certificates, please modify according to the usage scenario.