Arduino nano and hc05 problem please help!!!

Hello,

Im am using an arduino nano and a hc05 to play with bloutooth. I am connecting the hc05 to the rx and tx pin of the arduino.

It was working well but suddenly everytine y connect it to the arduino the rx led from the arduino turns on regardless the code i upload.

If i use the arduino without the hc05 connected it works well.

I am able to pair a cellphone with the hc05

Update: i connected the hc05 using software serial and the tx led also is always on like the module is constantly transmiting something. I tried to print that on theserail but nothing happens

Any help?

Thanks in advance

A little more information if you dont mind.

Schematic would be nice.
Do you have RX to TX and vice versa or RX to RX etc.

Makes a big difference.

Code would also be great but please use CODE TAGS ( </> ) to post it.
Or use the “Copy For Forum” option in the IDE (assuming desktop IDE)

Thanks for the answer

Schematic:
hc05 tx >> arduino rx
hc05 rx >> arduino tx
hc05 vcc >> arduino 3v
hc05 gnd >> arduino gnd

It happens with any code even with the basic led example.

It was working well. I disconnected by mistake the hc05 rx and tx while the arduino was on, but as far as i read that should no be the problem.

I do not know if there is a way to reset the hc05.

Thanks,
Marco

Hello,

Im am using an arduino nano and a hc05 to play with bloutooth. I am connecting the hc05 to the rx and tx pin of the arduino.

It was working well but suddenly everytine y connect it to the arduino the rx led from the arduino turns on regardless the code i upload.

If i use the arduino without the hc05 connected it works well.

I am able to pair a cellphone with the hc05

Update: i connected the hc05 using software serial and the tx led also is always on like the module is constantly transmiting something. I tried to print that on theserail but nothing happens

Any help?

Thanks in advance

rossi86m:
It was working well but suddenly..............

Who would ever know? I can only guess that you have changed something.

You might find the following background notes useful for checking

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

Nick_Pyner:
Who would ever know? I can only guess that you have changed something.

You might find the following background notes useful for checking

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

Thanks for the answer

The thing is that as soon as i start the arduino the hc05 seems to transmit data without having a device paired

Do you know if there is a way to hard reset it?

I tried to print what the hc05 seems to be transmitting but nothing. I can pair a device but the transmittion is not working

I also tried to disconnect everything from the arduino except from the hc05

Thanks,

Hope someone can help me

rossi86m:
The thing is that as soon as i start the arduino the hc05 seems to transmit data without having a device paired

It sounds complete nonsense, but may be true. It certainly isn't relevant. What is relevant is what is receiving it.

I tried to print what the hc05 seems to be transmitting but nothing. I can pair a device but the transmittion is not working

Anything that is being transmitted, can be seen on the serial monitor.

I also tried to disconnect everything from the arduino except from the hc05

That sounds a good idea. Your problem may have been inadequate power.

Nick_Pyner:
It sounds complete nonsense, but may be true. It certainly isn’t relevant. What is relevant is what is receiving it. Anything that is being transmitted, can be seen on the serial monitor. That sounds a good idea. Your problem may have been inadequate power.

Yes the thing is that having done all that i can not resolve the problem. I am about to buy a new hc05.

Any other idea?

Hello,

Im am using an arduino nano and a hc05 to play with bloutooth. I am connecting the hc05 to the rx and tx pin of the arduino.

It was working well but suddenly everytine y connect it to the arduino the rx led from the arduino turns on regardless the code i upload.

If i use the arduino without the hc05 connected it works well.

I am able to pair a cellphone with the hc05

Schematic:
hc05 tx >> arduino rx
hc05 rx >> arduino tx
hc05 vcc >> arduino 3v
hc05 gnd >> arduino gnd

Update: i connected the hc05 using software serial, using pins 10 and 11, and the tx led also is always on like the module is constantly transmiting something. I tried to print that on theserail but nothing happens
Any help?

Thanks in advance

Is your Arduino controller 3V or 5V? Of you are running at 5V you need to have a voltage divider for signals that go from the Arduino to the HC-05 (TX Arduino -> RX HC-05) or you will damage it.

marco_c:
Is your Arduino controller 3V or 5V? Of you are running at 5V you need to have a voltage divider for signals that go from the Arduino to the HC-05 (TX Arduino -> RX HC-05) or you will damage it.

I was using it at 5v. Do you think that it is damage?

Thanks,
Marco

Probably not. He should have said "may" not "will", but using the divider is a good idea.
You may have a problem with power and you need to be clear about what sort of bluetooth module you are using. If there is any writing on the back, read it twice.

Your code is apparently a secret, so no need to comment there.

If you are able to pair and connect your phone, it means just that, which is a good start, but it has nothing to do with Arduino.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

Nick_Pyner:
Probably not. He should have said "may" not "will", but using the divider is a good idea.
You may have a problem with power and you need to be clear about what sort of bluetooth module you are using. If there is any writing on the back, read it twice.

Your code is apparently a secret, so no need to comment there.

If you are able to pair and connect your phone, it means just that, which is a good start, but it has nothing to do with Arduino.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

For some reason myserial loops in the available loop even if the hc is desconected

Connections
Hc rx >> arduino d10
Hc tx >> arduino d11
Hc gnd >> arduino gnd
Hc 5v >> arduino 5v

This is my code

SoftwareSerial mySerial(10, 11); // RX, TX

Void setup(){
mySerial.begin(9600);  
Serial.begin(9600);
}

Void Loop() {
if (mySerial.available() > 0)
    {
        string = "";
    
      while(mySerial.available() > 0)
      {
        command = ((byte)mySerial.read());
            Serial.print("Bluetooth: "); Serial.print(command); Serial.print("\n");
        if(command == ':')
       {
            
           break;
           
        }else
        {
           string += command;
        }
      }
    }
}

If i plug the rx and tx from the hc tothe tx and rx from the arduino the rx led is always on

Any idea??

Thanks!!

rossi86m:
Any other idea?

Yes. Learn to use the one you've got. There is nothing to suggest it is faulty and quite a lot to suggest it isn't, so buying a new one is more likely to be simply moving the problem rather than solving it.

rossi86m:
For some reason myserial loops in the available loop even if the hc is desconected

Connections
Hc rx >> arduino d10
Hc tx >> arduino d11

SoftwareSerial mySerial(10, 11); // RX, TX

The loop loops waiting for something to happen. It neither knows nor cares if bluetooth is connected or not. The wiring is wrong. There is only one way to connect, the right way - Rx>Tx and Tx>Rx, as is clearly explained in the notes. Don't bother trying anything else.

You will get on a lot better if you confine your thread to one forum.,

Do not cross-post. Other thread removed.

Do not hijack.

Do not cross-post. Other thread removed.

Do not cross-post. Threads merged.