Basic Bluetooth communication with Arduino & HC-05

1// We will receive from pin 10 and transmit to pin 11
2const int BTRX  = 10;
3const int BTTX = 11;
4
5// Output LED at pin 13
6const int LED  =  13;
7
8// We will use this variable to keep track of the status
9int val =  0;
10
11// We use software serial to avoid conflicts
12// with the default RX/TX  pins of the Arduino board
13#include <SoftwareSerial.h>
14SoftwareSerial SerialBT(BTRX,  BTTX);
15
16// Define the message
17String msg; 
18
19// Setup the connection
20void  setup() {
21  SerialBT.begin(9600);
22  SerialBT.println("Bluetooth connection  is established");
23  pinMode(LED, OUTPUT);
24}
25
26//    Loop waiting for  a message in every iteration
27//    Analyze message,
28//    Trigger action (LED  on / off / check status)
29
30void loop() {
31  if (SerialBT.available()){      //  Data are pending
32     msg = SerialBT.readString(); // Read the message
33     if  (msg == "on") {
34         digitalWrite(LED, HIGH);
35         SerialBT.print("LED  at Pin ");
36         SerialBT.print(LED);
37         SerialBT.println(" is  ON");
38      } 
39      else
40      if (msg == "off") {
41         digitalWrite(LED,  LOW);
42         SerialBT.print("LED at Pin ");
43         SerialBT.print(LED);
44         SerialBT.println(" is OFF");
45      }
46      else
47      if (msg  == "status") {
48        val = digitalRead(LED);
49        SerialBT.print("LED  at Pin ");
50        SerialBT.print(LED);
51        SerialBT.println(" is ");
52        if (val == 0) {
53          SerialBT.println("OFF");
54        } else  {
55          SerialBT.println("ON");
56        }
57      }
58      else {
59         SerialBT.print("Command <");
60         SerialBT.print(msg);
61         SerialBT.println(">  is unknown");
62      }
63    }
64}                                          

1// We will receive from pin 10 and transmit to pin 11
2const int BTRX
3  = 10;
4const int BTTX = 11;
5
6// Output LED at pin 13
7const int LED  =
8  13;
9
10// We will use this variable to keep track of the status
11int val =
12  0;
13
14// We use software serial to avoid conflicts
15// with the default RX/TX
16  pins of the Arduino board
17#include <SoftwareSerial.h>
18SoftwareSerial SerialBT(BTRX,
19  BTTX);
20
21// Define the message
22String msg; 
23
24// Setup the connection
25void
26  setup() {
27  SerialBT.begin(9600);
28  SerialBT.println("Bluetooth connection
29  is established");
30  pinMode(LED, OUTPUT);
31}
32
33//    Loop waiting for
34  a message in every iteration
35//    Analyze message,
36//    Trigger action (LED
37  on / off / check status)
38
39void loop() {
40  if (SerialBT.available()){      //
41  Data are pending
42     msg = SerialBT.readString(); // Read the message
43     if
44  (msg == "on") {
45         digitalWrite(LED, HIGH);
46         SerialBT.print("LED
47  at Pin ");
48         SerialBT.print(LED);
49         SerialBT.println(" is
50  ON");
51      } 
52      else
53      if (msg == "off") {
54         digitalWrite(LED,
55  LOW);
56         SerialBT.print("LED at Pin ");
57         SerialBT.print(LED);
58
59         SerialBT.println(" is OFF");
60      }
61      else
62      if (msg
63  == "status") {
64        val = digitalRead(LED);
65        SerialBT.print("LED
66  at Pin ");
67        SerialBT.print(LED);
68        SerialBT.println(" is ");
69
70        if (val == 0) {
71          SerialBT.println("OFF");
72        } else
73  {
74          SerialBT.println("ON");
75        }
76      }
77      else {
78
79         SerialBT.print("Command <");
80         SerialBT.print(msg);
81         SerialBT.println(">
82  is unknown");
83      }
84    }
85}