Create Your First Connected Light using Arduino Yun

1#include <SPI.h>
2#include <YunClient.h>
3#include <PubSubClient.h>
4/*  ------------------ */
5/* SKETCH CREDENTIALS */
6/* ------------------ */
7char*  deviceId     = "<DEVICE-ID>";             // * set your device id (will be the  MQTT client username)
8char* deviceSecret = "<DEVICE-SECRET>";         // *  set your device secret (will be the MQTT client password)
9char* outTopic     =  "devices/<DEVICE-ID>/set"; // * MQTT channel where physical updates are published
10char*  inTopic      = "devices/<DEVICE-ID>/get"; // * MQTT channel where lelylan updates  are received
11char* clientId     = "<CLIENT-ID>";             // * set a random  string (max 23 chars, will be the MQTT client id)
12/* ------------ */
13/* SKETCH  LOGIC */
14/* ------------ */
15/* Server settings */
16byte server[] = { 96,  126, 109, 170 }; // MQTT server address
17/* Sample payload published to lelylan  */
18/* The id is the status property id of the basic light /*
19/* http://lelylan.github.io/types-dashboard-ng/#/types/518be107ef539711af000001/  */ 
20char* payloadOn  = "{\\"properties\\":[{\\"id\\":\\"518be5a700045e1521000001\\",\\"value\\":\\"on\\"}]}";
21char*  payloadOff = "{\\"properties\\":[{\\"id\\":\\"518be5a700045e1521000001\\",\\"value\\":\\"off\\"}]}";
22/*  Yun configuration */
23byte mac[] = { 0xA0, 0xA0, 0xBA, 0xAC, 0xAE, 0x12 };
24YunClient  yun;
25/* MQTT communication */
26void callback(char* topic, byte* payload, unsigned  int length); // subscription callback
27PubSubClient client(server, 1883, callback,  yun);         // mqtt client
28/* Pins configuration */
29int inPin = 3; // button
30int  outPin = 13; // led
31/* Button and led logics */
32int state = HIGH;     // current  state of the output pin
33int reading;          // current reading from the input  pin
34int previous = LOW;   // previous reading from the input pin
35long time  = 0;        // the last time the output pin was toggled
36long debounce = 200;  // the debounce time, increase if the output flickers
37/* arduino setup */
38void  setup() {
39  Serial.begin(9600);
40  delay(500);
41  Serial.println("Start  initialization of Yun...");
42  Bridge.begin();
43  Serial.println("Bridge finished  setup");
44  Serial.println("Starting connection to lelylan...");
45  lelylanConnection();      // MQTT server connection
46  pinMode(inPin, INPUT);    // button pin setup
47  pinMode(outPin, OUTPUT);  // led pin setup
48}
49/* arduino loop */
50void  loop() {
51  lelylanConnection();
52  char* value;
53  reading = digitalRead(inPin);  // read the button state
54  // if the input just went from LOW and HIGH and  we've waited long enough to ignore
55  // any noise on the circuit, toggle the  output pin and remember the time
56  if (reading == HIGH && previous == LOW &&  millis() - time > debounce) {
57    if (state == LOW) {
58      Serial.println("[PHYSICAL]  Led turned on");
59      lelylanPublish("on");
60      state = HIGH;
61    }  else {
62      Serial.println("[PHYSICAL] Led turned off");
63      lelylanPublish("off");
64      state = LOW;
65    }
66    time = millis();
67  }
68  // effectively update  the light status
69  digitalWrite(outPin, state);
70  previous = reading;
71}
72/*  MQTT server connection */
73void lelylanConnection() {
74  // add reconnection  logics
75  if (!client.connected()) {
76    // connection to MQTT server
77    if  (client.connect(clientId, deviceId, deviceSecret)) {
78      Serial.println("[PHYSICAL]  Successfully connected with MQTT");
79      lelylanSubscribe(); // topic subscription
80    }
81  }
82  client.loop();
83}
84/* MQTT publish */
85void lelylanPublish(char*  value) {
86  if (value == "on")
87    client.publish(outTopic, payloadOn); //  light on
88  else
89    client.publish(outTopic, payloadOff); // light off
90}
91/*  MQTT subscribe */
92void lelylanSubscribe() {
93  client.subscribe(inTopic);
94}
95/*  Receive Lelylan message and confirm the physical change */
96void callback(char*  topic, byte* payload, unsigned int length) {
97  // copu the payload content into  a char*
98  char* json;
99  json = (char*) malloc(length + 1);
100  memcpy(json,  payload, length);
101  json[length] = '\\0';
102  // update the physical status  and confirm the executed update
103  if (String(payloadOn) == String(json)) {
104    Serial.println("[LELYLAN] Led turned on");
105    lelylanPublish("on");
106    state = HIGH;
107  } else {
108    Serial.println("[LELYLAN] Led turned off");
109    lelylanPublish("off");
110    state = LOW;
111  }
112  digitalWrite(outPin,  state);
113  free(json);
114}