ble controlling a DC motor with ESP32 Board and L293D

I’m having trouble changing from an uno board to ESP32 board. I have looked for examples of code but they all seem to be for boards other than the ESP32 board. I have modified an LCD code file but it keeps giving me errors. It doesn’t like me using an int or float for rx and tx values. Its probably something simple but I’m not sure where to go.

    Based on Neil Kolban example for IDF:
    Ported to Arduino ESP32 by Evandro Copercini

   Create a BLE server that, once we receive a connection, will send periodic notifications.
   The service advertises itself as: 6E400001-B5A3-F393-E0A9-E50E24DCCA9E
   Has a characteristic of: 6E400002-B5A3-F393-E0A9-E50E24DCCA9E - used for receiving data with "WRITE"
   Has a characteristic of: 6E400003-B5A3-F393-E0A9-E50E24DCCA9E - used to send data with  "NOTIFY"

   The design of creating the BLE server is:
   1. Create a BLE Server
   2. Create a BLE Service
   3. Create a BLE Characteristic on the Service
   4. Create a BLE Descriptor on the characteristic
   5. Start the service.
   6. Start advertising.

   In this example rxValue is the data received (only accessible inside that function).
   And txValue is the data to be sent, in this example just a byte incremented every second.
#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>

BLECharacteristic *pCharacteristic;
bool deviceConnected = false;
int txValue = 0;
int rxValue = 0;
const int motorPin1 = 18; // pin 2 on L293D IC
const int motorPin2 = 17; // pin 7 on L293D IC
const int enablePin = 16; // pin 1 on L293D IC

//std::string rxValue; // Could also make this a global var to access it in loop()

// See the following for generating UUIDs:

#define SERVICE_UUID           "6E400001-B5A3-F393-E0A9-E50E24DCCA9E" // UART service UUID
#define CHARACTERISTIC_UUID_RX "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
#define CHARACTERISTIC_UUID_TX "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"

class MyServerCallbacks: public BLEServerCallbacks {
    void onConnect(BLEServer* pServer) {
      deviceConnected = true;

    void onDisconnect(BLEServer* pServer) {
      deviceConnected = false;

class MyCallbacks: public BLECharacteristicCallbacks {
    void onWrite(BLECharacteristic *pCharacteristic) {

      if (rxValue.length() > 0) {
        Serial.print("Received Value: ");

        for (int i = 0; i < rxValue.length(); i++) {


        // Do stuff based on the command received from the app
        if (rxValue.find("1") != -1) {
          Serial.print("Turn Clockwise!");
          digitalWrite(motorPin1, HIGH);
          digitalWrite(motorPin2, LOW);
        else if (rxValue.find("2") != -1) {
          digitalWrite(motorPin1, LOW);
          digitalWrite(motorPin2, LOW);
        else if (rxValue.find("3") != -1) {
          Serial.print("Turn Counter Clockwise!");
          digitalWrite(motorPin1, LOW);
          digitalWrite(motorPin2, HIGH);


void setup() {

  // sets the pins as outputs:
  pinMode(motorPin1, OUTPUT);
  pinMode(motorPin2, OUTPUT);
  pinMode(enablePin, OUTPUT);
  // sets enablePin high so that motor can turn on:
  digitalWrite(enablePin, HIGH);

  // Create the BLE Device
  BLEDevice::init("MyESP32"); // Give it a name

  // Create the BLE Server
  BLEServer *pServer = BLEDevice::createServer();
  pServer->setCallbacks(new MyServerCallbacks());

  // Create the BLE Service
  BLEService *pService = pServer->createService(SERVICE_UUID);

  // Create a BLE Characteristic
  pCharacteristic = pService->createCharacteristic(

  pCharacteristic->addDescriptor(new BLE2902());

  BLECharacteristic *pCharacteristic = pService->createCharacteristic(

  pCharacteristic->setCallbacks(new MyCallbacks());

  // Start the service

  // Start advertising
  Serial.println("Waiting a client connection to notify...");

void loop() {
  if (deviceConnected) {
    pCharacteristic->setValue("Hello!"); // Sending a message

    pCharacteristic->notify(); // Send the value to the app!
    Serial.print("*** Sent Value: ");
    Serial.println(" ***");

    if (rxValue.find("1") != -1) {
      digitalWrite(motorPin1, HIGH);
      digitalWrite(motorPin2, LOW);
    else if (rxValue.find("2") != -1) {
      digitalWrite(motorPin1, LOW);
      digitalWrite(motorPin2, LOW);
    else if (rxValue.find("3") != -1) {
      digitalWrite(motorPin1, LOW);
      digitalWrite(motorPin2, HIGH);
      Serial.println("Counter Clockwise!");