Bluetooth configuration problem Hc-05 with Arduino.

Using Arduino Programming Questions
1

Hi, I'm trying to set up my Bluetooth HC-05 but I'm having problems. I am using an Arduino Uno and I connect the bluetooth TX and RX cables to 0 and 1 of the Arduino. The code I am using is the following:
#include <SoftwareSerial.h> // Incluimos la librería SoftwareSerial
SoftwareSerial BT(0,1); // Definimos los pines RX y TX del Arduino conectados al Bluetooth

void setup()
{
Serial.begin(9600); // Inicializamos el puerto serie
BT.begin(38400); // Inicializamos el puerto serie BT (Para Modo AT 2)
Serial.println("Introduzca un comando:");
}

void loop()
{
if(BT.available()) // Si llega un dato por el puerto BT se envía al monitor serial
{
Serial.write(BT.read());
}

if(Serial.available()) // Si llega un dato por el monitor serial se envía al puerto BT
{
BT.write(Serial.read());
}
}

The problem comes when I open the serial monitor to send AT commands but I do not receive the correct message, I receive the following image.

https://drive.google.com/file/d/1StjO7i8S_lsV39meM8L2SeVMe-TT-ZPb/view?usp=sharing

I first show a message but when I enter the AT command, instead of receiving OK I receive xxxo. I suppose it is due to the bauds but I do not know how to put them, because the bluetooth I use was left to me and apparently it is already configured and I want to make changes, but it does not show me AT messages in a visible way.

2

You can't use pins 0 and 1 with SoftwareSerial as these are connected to the USART for USB communications (downloading your sketch and stuff like that). Technically you could by disabling the USART, but that would mean losing your primary means of communication with the board. Simplest solution, pick two other pins for use with SoftwareSerial. I usually use 7 and 8.

3

You may want to check out martyn currey's tutorial on AT mode with the HC 05.

http://www.martyncurrey.com/hc-05-with-firmware-2-0-20100601/#HC-05