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ESP32 Code: Connect ESP32 to Bluetooth, work  and write and read commands


This code example shows whatyou can connect an ESP32 microprocessor to a smartphone and then send commands to control the application and read the jam.


ESP32 WROOM32 nodeMCU, Arduino, DevBoard, Serial Bluetooth


Example : Send Start via theSerialBluetooth connection to start the application on ESP32 nodeMCU


Then you start the app on your smartphone: Serial Bluetooth Terminal and connect the application of the smartphone to ESP32



Then you can enter a command like "Start" in the input line of Bluetooth Serial Terminal


Entering commands

After sending the text: Start

Shows the received text on the Serial Monitor  of Arduino IDE.




ESP32 Code: Simple code to test


#include "BluetoothSerial.h"



#error Bluetooth is not enabled! Please run `make menuconfig` to and enable it



BluetoothSerial SerialBT;  //Serial Bluetooth send and receive

String message = "";




void setup() {

    //----< setup() >------

    Serial.begin(115200); //*for local monitor

    SerialBT.begin("ESP32_Bluetooth"); //Bluetooth device name

    Serial.println("The device started, now you can pair it with bluetooth!");

    //----</ setup() >------



void loop() {

    //----< loop() >------


    //-< read Bluetooth >-

    // get command from smartphone

    if (SerialBT.available()) {

        char incomingChar =;

        if (incomingChar != '\n') {

            message += String(incomingChar);


        else {

            message = "";




    //-</ read Bluetooth >-


    //-< do command >-

    if (message == "Start") {

        Serial.println("Start");  //serial monitor



    //-</ do command >-

    //----</ loop() >------



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