Serial Monitor does not display data

Cannot get Arduino BT serial Monitor to work. When I upload the board, everything works, I get the proper messages on the IDE window and the board works fine, but when I click on the “serial monitor” Button to monitor data, I get the window on my laptop screen but nothing is written to it (I try “Hello world” with no results Configuration: Laptop Acer aspire 5500 with internal BT BT mouse Windows XP pack 2 Arduino BT Arduino-0012 Alpha.

Any idea? Thank you

It would help if we could see your code.

the code is the classical "hello world" without change other than speed (115200), same speed on the serial monitor but I have the same behavior with all codes. the board work perferly but no feedback on the serial monitor. It work OK if I use hyperterminal to communicate with the board Code: /* * Hello World! * * This is the Hello World! for Arduino. * It shows how to send data to the computer */

void setup() // run once, when the sketch starts { Serial.begin(115200); // set up Serial library at 9600 bps

Serial.println("Hello world!"); // prints hello with ending line break }

void loop() // run over and over again { // do nothing! }


The built-in serial monitor runs at 9600 baud. If you want to talk to it, you must also run the hardware at 9600 baud.


Thank you for the feedback, Does that mean that I have to set "Serial.begin(115200)" as Serial.begin(9600) ?

If you want to talk to the Arduino IDE's serial monitor, yes.


The Arduino IDE serial monitor will work at 115200 baud. When you turn the monitor on, there is a dropdown box above the monitor window that allows selection of baud rates from 300 to 115200 baud.

Thanks for the correction mem. I didn't have an arduino attached when I checked, so I missed that.


Thanks for your comments but I'm back to square one. Any other suggestion? Noega33

You are printing your “hello world” rather early if you need to allow time for the human to click the serial monitor button, change the speed, and start paying attention. I don’t think that the monitor collects or displays any data from the time period before it started. In a recent sketch I did the following so that I could know WHEN the arduino was going to do its serial output:

void loop()
  int i;

  for (i=0; i <  10; i++) {  // blink light while we wait for serial monitor to get turned on
     digitalWrite(13, 1);
  Serial.print("Tone generater debug.  Total tones=");

I'll try yhis tonight, but I had the same issue when I was printing using a loop (so giving enough time). Thank you

You are printing your "hello world" rather early if you need to allow time for the human to click the serial monitor button, change the speed, and start paying attention.

I think changing the speed and/or clicking the serial monitor button causes the IDE to reset the Arduino. At least it does on my Diecimilas (although I understand some flavors of Arduino do not auto-reset under these conditions). Timing should not be an issue (generally).


I don't know what's ging on, but it seems that the IDE is very unstable. It crashes a lot. I finally managed to get it working (sending data back to the seril monitor), but it is nit stable. Sometime, I have to push the board reset button before clicking on the upload button, sometimes it is the reverse.... I guess that I'll be using the IDE to load the board and use something else to communicate. Anyway, my final application will be using VBA.... keep on communicating, sharing ideas Cheers Noega33