Tutorial: ESP32 Bluetooth Classic | How to get started with ESP32 | Arduino IDE

 1 #include <BluetoothSerial.h>  
 2   
 3 // Pin assignments  
 4 #define BLUE_LED  25  
 5 #define GREEN_LED  26  
 6 #define RED_LED   27  
 7   
 8 // Instantiate a bluetooth serial  
 9 BluetoothSerial SerialBT;  
10   
11 // Variable for LED states  
12 bool bluLedState = false;  
13 bool grnLedState = false;  
14 bool redLedState = false;  
15   
16 // Character buffer for incoming bluetooth data  
17 char bufferData[8];   // holds the char data, 
18                       // 	increase this if you will use longer commands  
19 char bufferIndex = 0; // holds the position of the char in the buffer  
20   
21 void setup() {  
22  // Create the Bluetooth device name  
23  SerialBT.begin("ESP32-BT");  
24   
25  // Set the pin directions  
26  pinMode(BLUE_LED, OUTPUT);  
27  pinMode(GREEN_LED, OUTPUT);  
28  pinMode(RED_LED, OUTPUT);  
29 }  
30   
31 void loop() {  
32  manageBT();  
33 }  
34   
35 void manageBT() {  
36   
37  // Manage the incoming bluetooth data  
38  if (SerialBT.available()) {  
39   // read a single character from BT and store it in a char variable inchar  
40   char inchar = (char) SerialBT.read();  
41     
42   if (inchar != 'n') {                       // checks if character is not Carriage Return  
43    bufferData[bufferIndex++] = inchar;        //  if not, store it in our buffer  
44   } else {                                    //  else,  
45    bufferIndex = 0;                           //  reset our buffer index  
46    memset(bufferData, 0, sizeof(bufferData)); //   and our buffer  
47   }  
48  }  
49   
50  // Execute a specific task according to bluetooth command  
51  // String compare function basically compares the 2 string  
52  //  and if characters are the same, returns 0  
53  if        (strcmp(bufferData, "Red:1") == 0) {  
54   redLedState = true;  
55   SerialBT.println("Red LED On");  
56  } else if (strcmp(bufferData, "Red:0") == 0) {  
57   redLedState = false;  
58   SerialBT.println("Red LED Off");  
59  } else if (strcmp(bufferData, "Grn:1") == 0) {  
60   grnLedState = true;  
61   SerialBT.println("Green LED On");  
62  } else if (strcmp(bufferData, "Grn:0") == 0) {  
63   grnLedState = false;  
64   SerialBT.println("Green LED Off");  
65  } else if (strcmp(bufferData, "Blu:1") == 0) {  
66   bluLedState = true;  
67   SerialBT.println("Blue LED On");  
68  } else if (strcmp(bufferData, "Blu:0") == 0) {  
69   bluLedState = false;  
70   SerialBT.println("Blue LED Off");  
71  }  
72   
73  // Update the LED state  
74  digitalWrite(BLUE_LED, bluLedState);  
75  digitalWrite(GREEN_LED, grnLedState);  
76  digitalWrite(RED_LED, redLedState);  
77 }