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HC-06 Bluetooth Module To Arduino Uno

I bought recently one HC-06 Bluetooth Module and i want to connect it on my arduino like a remote serial to send the data from arduino to my pc via bluetooth. I put some image about the wiring is this right? I upload two of the bluetooth module Front and Back and one of the wiring. Please Check them and tell me if is correct
Front.JPG2.83 KB
Back.JPG66.62 KB
Wiring.jpg54.3 KB

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And how level shifting is going to help? What is the purport of this?

Quite simple. The bluetooth module uses 3.3v logic, the arduino uno uses 5v logic

inputting a 5v signal into a 3.3v device will simply fry it, no point beating around the bush, they plain dont like it and will be damaged by a 5v signal. Bye bye bluetooth module.

The other way around, ie 3.3V from the bluetooth module into the 5v arduino wont be a problem, the arduino might not necessarily read it though (however normally it will, I think they tend to read anything above 2.5-2.7v fine, they just arent supposed to).

You can buy level shifters for serial, they will simply have a side for connecting your 5v lines and a side for your 3.3v lines, it will then take the 5v TX line (as seen by the uno) and turn the 5v signal into a 3.3V signal and then have another set of pins where you input the 3.3V TX from the bluetooth module and it will output 5V for the arduino (to connect to the RX).

In serial you always wire TX to RX. Breaks the old rule of +5V to +5V and GND to GND etc. TX will be the serial output (transmit) for the device and RX (receive) is the input. So of course the output/TX of one device has to go to the input/RX of the other and vice versa.


In future, just keep an eye out for what voltage your devices use as its not consistent. Its not even consistent across arduinos, the UNO and MEGA boards are both 5v, the due is 3.3v, the nano confusingly is available in both 3.3v and 5v versions. Raspberry pi, stellaris launchpad, STM Discovery and generally anything ARM based is 3.3v. If you look back through history there are devices using different voltages yet again. Different sensors and external modules may also use different voltages, the HC-SR04 ultrasound module is 5v so when I used it with a raspberry pi I needed to make a voltage divider as a crude way to drop the 5v to 3.3v (or in reality mine is closer to 3.0 but the pi is happy to read that as its close to but still under 3.3), I have had conflicting opinions in the shoutbox as to whether a voltage divider is safe for serial though (I think yes, but having been told by someone no, I am not trying until I get a more definitive answer or reason), the HC-SR04 would be fine with an UNO though. Your bluetooth module is 3.3V so would work fine with a pi but needs level shifting for the UNO.

Well if you weren't lazy and had read the link I've shared before you might already known. :|

And how i suppose to make a level shifting sub-circuit? Can you guide me?

well you know you could have easily searched for "level shifting" or "logic level shifting" either here or on google... still the one I use is this:



I Just want a way to connect it on my Arduino Uno And receive it data on my pc. IF i connect RX to Arduino RX   and  TX to arduino TX is there any chance to destroy my bluetooth module or my arduino pin?

Well first of all serial connections are made RX -> TX and TX -> RX

Second of all if as I suspect the RX & TX of the bluetooth module aren't 5V tolerant you might indeed ruin the module if you don't use any level shifting option.

I decided to take no chance with mine and do employ level shifting on the RX/TX pins of my HC-06.


I do believe you need level shift translation between the HC06 RX/TX pins and the UNO TX/RX pins, that if you are indeed to connect it to an arduino uno and not a nano as shown on the picture.

Unless you're specific version of the HC-06 mounted model already includes a level shifting sub-circuit, something the pictures tell me little about.