Android + Bluetooth + Arduino = Not Working

[Brown]

Hi, I got a HC-05 BT Module and an Android I tried this http://www.instructables.com/id/Andruino-A-Simple-2-Way-Bluetooth-based-Android-C/ and it doesn't work. my phone connects with the module but the led wont turn off or on

[Lurch]

Something must be wrong then.

Usual cause of things not working is wiring errors. Usually people say 10 times that it is correct and then on page 4 the OP comes back and says 'oops, wire in wrong hole lol' so check and recheck everything.

[psycho0815]

Yeah check the wirering. Also, there are HC05 Modules out there that have 5V logic on the rx and tx lines (i know because i have one), so make sure yours is in fact 3.3V level. Otherwise loose the voltagedivider on the modules rx-pin. Also check the baud-rate. I think these things come with 9600-Baud, but that can be changed.
Also try not powering the arduino from USB if youre doing that. Could be that the usb-uart chip is interfering. Not sure about that though, i only ever used those modules with SoftSerial on Arduino.

[Brown]

Ok so, I tried this http://www.instructables.com/id/Arduino-AND-Bluetooth-HC-05-Connecting-easily/?ALLSTEPS and it worked! Thanks