View Full Version : aubtm-20 bluetooth module

03-06-2011, 07:56 PM

this is vivek from mumbai.
I am using aubtm-20 for my Final year Graduate degree in Electronics Engg.
I am just not able to communicate(send AT commands) to aubtm from PC(hyperterminal winXP).
hyperterminal settings: baud rate : 9600 bps, data bits :8, stop bits: 1, parity: none, flow control: none
to enter command mode, i send LLL from hyperterminal within 60sec of powering ON aubtm-20.
BUT i get no response at all.

Please describe in detail the method i should use to send AT commands to aubtm-20 and receive responses.
I would be grateful for your kind assistance. I have to complete my project in just a weeks time.
Please Help. Awaiting your response.

thank you,
Vivek M

03-06-2011, 07:57 PM

03-07-2011, 08:36 AM
Most blue tooth modules i have used is based on 3.3 volt operation so MAX232 wont work! What is the VCC of MAX232 you can giving? If its 5v then buy a new bluetooth module

Where you have bought the modules?

You have to use a LM1117-3.3 volt IC to power up the module. Then use a zener 3.3 volt adaptor at i/o pins. Use a USB to TTL module like this


You may have a look at my setup here

Sorry admin for posting a link to my forum, as your upload policy is weired :( ! Increase the image update max size and resolution)

03-07-2011, 07:14 PM
i give 3.3v to bluetooth module (2 AA batteries) and 5v supply to max232 ic.

is it the 3.3v supply dat i give to aubtm-20(bluetooth module) creating problems?
i got this module from a distributor Rajguru Electronics, lamington rd, mumbai.

i didnt get ur 3.3v to 5v zener adaptor. Could you please elaborate or give a schematic?

03-07-2011, 07:34 PM

is this the connection u meant?

03-07-2011, 08:29 PM

there is a 3.3v pin on this board.

what is the purpose of this pin? is it a supply(VDD) pin?