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[on:]

Hello im new in electronics and i have a problem with a Bluetooth module (HC-05) that i ordered from ebay (about 5$). It works at 3.3v and my arduino uno at 5v.. so i followed this http://www.instructables.com/files/deriv/F4H/8GM6/H1QML3ZC/F4H8GM6H1QML3ZC.LARGE.jpg
to connect it safely to the arduino tx rx lines with a voltage divider. My problem is that with the voltage divider i receive from the bluetooth only random characters.. but if i connect it directly on the arduino rx tx lines i get the data normal but im afraid that the module will die like that.

[Reply #1 on:]

You might want to check the datasheet, I too also just bought an HC-05 from ebay (from the seller NYplatform), and the data sheet provided by the seller says that while the preferred voltage is 3.3 volts, it will work at 3.3 to 6 volts, so it should be usable by an Arduino without a voltage converter.  That being said, I just got it haven't yet hooked it up to the Arduino (or the Teensy 3.0 which is 3.3 volts).  Here the ebay listing for the unit I bought: http://www.ebay.com/itm/221158958927?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649.

[Reply #2 on:]

Hello, thank you for your answer but i got the HC-05 without the breakout board.. and it says that it accept up to 4.2. This is what i bought http://www.ebay.com/itm/251066012059?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 .. But why it doesnt work with the voltage divider (2.2k resistor and a 1k resistor)? i measured it with a multimeter and it outputs 3.3v :/