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Topic: Bluetooth controlled car (Read 1 time) previous topic - next topic


first of all,  hello everyone! (i'm new here)

now, i had an old rc car and removed all electronics from it.
i'm now controlling it with an arduino uno and i can make the car go anywhere.
now i also bought a bluetooth interface (bluesmirf silver) and connected it to the car.

i've never used bluetooth on my computer before and, after adding the bluesmirf to my bluetooth devices it seemed to work
but nearly always (not always!) when i try to use arduino serial monitor to communicate with the bluesmirf,
i get following erorr: "Serial port (com3) already in use. Try quitting any programs using it."

i'm sure no other process is "capturing" the com3 port.
i looked in device manager and saw that com3 port is always reserved for my bluesmirf (i mean it won't disappear when the bluesmirf isn't there, com3 is always there since the computer has installed drivers for bluesmirf). is it normal that com3 is always listed?
this means i can also choose com3 in arduino software when bluesmirf isn't even getting power. if i do so and try to launch serial monitor, i will also get the "port already in use" error (of course i'm getting an error but that's the same error which i get when the bluesmirf is active)

anybody here who knows whats going on?

thanks in advance,


still haven't found a solution...

can't somebody here just post how they connect to their bluetooth module using arduino?
this is what i try:
i boot my computer in windows 7 and enable my motherboard bluetooth adapter
i start arduino
i power my car (now my arduino and bluesmirf get power)
arduino uno is running program and bluesmirf blinks
i go back to arduino software and choose the correct com port
i click serial monitor
i get error



1) what are you using to control your robot, your PC?
2) did it properly pair up?
3) does your code upload correctly?
4) did you cross wire the TX and RX pins on the ARD and BT module?
5) you CAN NOT use serial monitor when the BT is connected to the ARD TX and RX pins.

Post any pictures and errors you are getting and your FULL code.
My GitHub:


5) you CAN NOT use serial monitor when the BT is connected to the ARD TX and RX pins.

Especially this.


If you want to debug your code, use serial.print and maybe use PuTTy or hyperterminal to view your data.
My GitHub:

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