HC-05 bluetooth module connection

Other Hardware Device Hacking
1

Hi,
I am trying to connect my computer to arduino uno using the HC-05 bluetooth module. I am trying receive data from my computer to the arduino and print it to the serial monitor. Here is my code:

#include <SoftwareSerial.h>

int bluetoothTx = 2; //TX-O pin of HC05
int bluetoothRx = 3; //Rx-I pin of HC05

SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

void setup() {
// put your setup code here, to run once:
bluetooth.begin(9600);
Serial.begin(9600);
}

void loop() {
// put your main code here, to run repeatedly:
if(bluetooth.available())
{
Serial.println(bluetooth.read());
}

if(Serial.available())
{
bluetooth.println(Serial.read());
}

}

I tried using putty and Tera Term to send data after connecting my computer to the bluetooth module. Now whenever I press a character key in Tera Term, I'm getting 254 printed on the serial monitor and when I press a number I get 255 on the serial monitor. I'm not able to get the Ascii character I sent. Can anyone help in finding the issue?

2

Not very clear what you want to do. And not very clear how you try to do this.
For me it sounds like some kind of loopback: PC sends via bluetooth to bluetooth module, Arduino "reads" from bluetooth module (via SoftSerial) and sends back (via HardwareSerial and USB) to PC.
That is what I read from your description, but i may be wrong.

You should tell us about your hardware setup.

What comes to my mind:

  1. RX (Arduino, Softserial) must be connected to TX (bluetooth module)
    and vice versa
    (not RX to RX and TX to TX)

  2. Arduino GND and bluetooth module GND must be connected

  3. If you want to do this kind of loopback (described above) then you may need 2 different programs (or at least 2 different instances) talking to 2 different COM ports. One for sending data and the other for receiving data.

  4. Try Serial.write instead of Serial.print