MQTT Wifi SPIFFS Thing utility

Purpose

Implement sensors and actuators on MQTT with TLS in just a few lines.

Features

• Selects the access point with the best signal automatically.
• Reconnects when the access point disconnects.
• Stores access points settings on SPIFFS.
• Stores MQTT settings on SPIFFS.
• Uses lambda for callbacks.
• Uses a generic Value class as data type.

Usage

Create a data folder with two files: mqtt.txt and wifi.txt. Write mqtt settings in mqtt.txt 1st line: server 2nd line: port 3rd line: username 4th line: password

Write access point settings in wifi.txt odd lines: ssid even lines: password

Set callback onStateChange.

Add sensor and actuator topic callbacks.

Call begin() inside setup() Call handle() inside loop()

Security weaknesses

Albeit the data streams are over TLS, there are many security weaknesses.

• SPIFFS can be easily downloaded from a sensor.
• No host check is performed on the TLS connection.

Example

#include "Thing.h"

using namespace ootb;

Thing thing;

int count = 0;

void setup()
{
  Serial.begin(230400);
  Serial.println();
  
  thing.onStateChange([](const String& msg){
    Serial.println(msg);
  });
  
  thing.addSensor("sensor/test", 1000, [](Value& v){
    v = count++;
  });
  
  thing.addActuator("display/test", [](Value& v){
    String msg = v; 
    Serial.println(msg);
  });
  
  thing.begin();
}

void loop()
{
  thing.handle();
}