DF-Bluetooth V3

[mikedeklerk]

Hi,

I have bought the following bluetooth module: http://www.dfrobot.com/index.php?route=product/product&path=45&product_id=360

And I have a few questions concerning its operation. Is it designed for receiving any input from other bluetooth devices?

My scenario:
- 12 volt power source adapter
- Uploaoded code with Serial.println("Hello"); and Serial.available()
- The bluetooth module on pins 0-Rx/1-Tx (Arduino Uno)
- Com port of the bluetooth module installed on my PC.
- Opened connection to the com port (Serial Monitor from Arduino IDE)
- receiving Hello from Arduino = communication from Bluetooth module -> PC works
- PC sending characters via Serial monitor the bluetooth = it does not receive any data. Or atleast does not send anything back when I use Serial.println(Serial.read());

The strange thing is. When i connect the Rx of the bluetooth module to the Tx of the bluetooth module (its talking to itself), and I send data using the Serial Monitor to the bluetooth device I get an echo. So when I type "bla", the bluetooth module receives "bla" and sends "bla" back and the serial monitor prints "bla"!!

So it is capable of sending, appearently. But not when the signal comes from the Arduino uno!?

Please help me! As I really want to make my project wireless!

Thanks in advance,
Mike

[luispena15]

Hello mikedeklerk!

I am using the same bluetooth module than you. I need to use it for communication between a robotic arm (controlled by arduino with the bluetooth module) and a blackberry phone. I have problems with communicate the arduino with bluetooth module and a computer. I see you said: "receiving Hello from Arduino = communication from Bluetooth module -> PC works" and I can´t do that.

Can you help me at this point? I am not able to get the "link LED" on and send "hello" to the computer.

Thanks a lot!

[Ricky]

Trouble shooting for Bluetooth device

1) Always be first thing to check the baud rate of any serial device. The V3 may work under 9600 and 115200 bps.  Try both baud rate.

[luispena15]

Hello admin!

Yes, I check the baud rate. I have "Serial3.begin(9600)" and this is the default configuration for the bluetooth module (as datasheet).

The problem is my laptop can read the data I am sending from my arduino (I saw the "link LED" in the bluetooth module is off).

Thanks!

[mikedeklerk]

Ok, I have 2-way communication with the df-bluetooth module now. I have put the Rx and Tx pins on the Arduino Uno digital pins 2/3 (interupts). And I have added the NewSoftSerial Library to create a serial connection. I have not got it working 100% correctly (yet). I sometimes get strange characters. But atleast I can send 1 characters commands with fidelity. I have used baudrate 9600. If it does not work, change the wires of the pins Rx <-> Tx, or change the pins on your initialization code. Be sure to use interupt ports.

Now I have the following issue. Whenever I use the servo or motor to move my robot, the Bluetooth connection resets. I guess this is due a voltage drop. What component can I put in the circuit to prevent the drop? I have read about capacitors/condensators but I have no experience with them at all. Can I use them for my problem? And how much farrad should I use? Can I damage my Arduino or other devices when I pick wrong values?

Atleast I am happy I have the bluetooth problem 'solved'.

@Admin:
I have rated the bluetooth devices as bad in the the store, but that one should be removed. i thought it only supported one-way communication. But I was wrong (luckily) Since it is the problem of the Arduino. Or at minimum a combination of the two.

Thanks in advance,
Mike

[Ke20]

Hi guys

I got exactly the same problem as mikedeklerk :
everything is setup correctly (pingback from BT module and from arduino serial) but i cannot send data from computer to rx pin of arduino
I tried with arduino uno and duemilnove
I hope admins can come back with a solution for this!
On the wiki the example was to read from the arduino .... If tghis module cannot write to the arduino it should be stated clearly
i will try the softserial to see if it solve something...
Best
Ke20

[Ke20]

I confirm the softserial is working perfectly!

@admins please include this info in the wiki to save customers time

Best

[Ke20]

This module is really bad for writing on it.

With the virtual serial it work almost but generate many errors on the arduino IDE like this :
java.io.IOException: Bad file descriptor in nativeDrain
   at gnu.io.RXTXPort.nativeDrain(Native Method)
   at

and so it is unusable in other applications as it draws java exceptions
When googling this you can see many other custormer having the same problem..... but it seems that nobody managed to solve it

I am very angry for losing so much time on it, I should buy a better BT shiled at first...

If someone find a solution please send it to me

best

Ke20

[Ricky]

We will definitely investigate this issue.

But we are still not clear what happened, what is the configuration of the project, I suppose that you guys want to send data from Arduino to a PC and receive data back from PC, right?

[Ke20]

@admin :Yes exactly !
Top sum up the problem : reading data from arduino is ok but sending data to arduino is the problem: it only works with softserial (i.e pins 2,3).
If I plug the RX on the Tx of the Dfrbluetooth everything work fine in echo but the Rx pin of arduino cannot read from the module...  (I tried with arduino uno and duemilnove)

Best