HC05 paired but losing connection


I bought myself a HC-05 Bluetooth module, I paired it, but after I connect it, it disconnects in about 2 seconds with the message on my Android:"Device connection was lost" . I also tried it on the PC, same problem. I see it, I can pair it but it disconnects. I also entered the AT command set, bluetooth is set to slave, baud rate is the default 9600,0,0 ....

Any suggestions how I could fix it?

I tried this program: http://www.instructables.com/id/Arduino-AND-Bluetooth-HC-05-Connecting-easily/?ALLSTEPS

and this: http://mitappsinventor.blogspot.in/2014/12/how-to-make-android-app-using-mit-app.html

Neither work because bluetooth disconnects before I can actually do something.(On the first one I don't see anything in the teraterm monitor or serial port monitor because it doesn't connect). I checked wiring and it's ok.

That could be down to inadequate power. The HC-05 is not famous for lower power consumption. I see a 9v battery is mentioned, which is usually the kiss of death, and a fair indication of the competency of the author. If you are not using a 9v wall wart, now is the time to get one. The USB cable from the PC is usually OK, but not always.

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

Thanks for the reply, still working on it. You mentioned that it could destroy the Bluetooth device. “Kiss of death”… I tried doing what was written in the link, and this programs says that bluetooth is connected. And I can see what I write on my Phone, on the Serial Monitor. Other programs tho, give me the same issue(disconnects after 2 sec). So my bluetooth should still be ok and not broken. Seems like Bluetooth terminal is the only one that keeps the connection.

CristiD: "Kiss of death"...

Pardon my bombast. I merely meant that those 9v batteries are a pretty good guarantee that your Arduino won't work and are best left in very low-drain devices they were designed for - like smoke detectors. In short, they are a guarantee of inadequate power. There is no risk of actual damage, just a lot of time wasted.

The reason why I raised this is that, with a 9v battery, everything is so marginal that, while power may be maintained when the LED on the Bluetooth is flashing, it might not be up to the job when the LED is steady, and it dies after two seconds.

I'm afraid I don't understand why Bluetooth terminal is the only one that keeps the connection. It's the phone that makes the connection, and the programme the phone is running should be irrelevant.

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After installing several Bluetooth programs I found out that I did everything allright, just 1 bluetooth Program wasn't working and the one that I tried from the first link with appinventor so I guess the problem is in the programming of the app and the way it connects(on the app from appinventor it doesn't connect at all).

Thank you for the support.

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i am also having the same problem …im using S4A which get hang after HC05 losses its connection …plz replay if u got my problm …i am using 7.5v power supply for arduino borad