So I have ordered an HC 06 Bluetooth module and an arduino nano and i’m wondering if I can just directly connect the RX and TX pins from the module to the arduino board without worrying that I might fry the HC06 ? because when I look at the images of the module I see power 3.6V to 6V so I guess I can just power it directly from the arduino BUT the RX and TX pins on the module say ‘Level 3.3V’ and from what I know the arduino TX and RX pins have 5 volts? so what should I do?,resistors?
If you do a search for the Bluetooth module you find that they do in fact require 3v3 and a suggestion to use resistors to step down the TX voltage from the Arduino.
Simontaga: I see power 3.6V to 6V so I guess I can just power it directly from the arduino BUT the RX and TX pins on the module say 'Level 3.3V' and from what I know the arduino TX and RX pins have 5 volts? so what should I do?,resistors?
Correct on both counts. You will see that it is a sandwich of two boards. The backboard has regulators to supply 3.3v power but does not handle the signals. It is good practice to use a 1k/2k divider for Arduino Tx, as Kiwi suggests. There is no need to worry about HC-06s Tx, Arduino handles 3,3v OK.
In this tutorial i see that they are not using the RX and the TX pins, does it still work? http://tronixlabs.com.au/news/tutorial-using-hc06-bluetooth-to-serial-wireless-uart-adaptors-with-arduino/
Yes it still works but it isn’t such a great idea and in this case a stupid one, so I’m surprised to see Boxall do this without explanation or qualification. It isn’t as if he wouldn’t know. What he has done is employ extra code, the software serial library, to convert pins 10,11 for use as a serial port, meanwhile leaving the hardware serial port, pins 0,1, which require no extra software, unused. There is some faint method in this madness in that it enables you to upload the programme, essentially a one-off operation, with the HC-06 connected. It would also enable you to send text from the serial monitor, but that is not done here and you can be sure there are better ways to talk to your phone from the PC via bluetooth anyway.
You might find the following background notes useful
Cool guide! just one last thing if i got it right i should perhaps use some resistors from the arduino to the HC06's RX and TX pins so which should i use? how many ohms?
Arduino Tx to HC-06 Rx. See section 4.
Nick_Pyner: Yes it still works but it isn't such a great idea and in this case a stupid one, so I'm surprised to see Boxall do this without explanation or qualification.
We do it that way to keep things as simple as possible for the random beginner, otherwise we receive the plethora of "can't upload sketch" emails. We will update the tutorial shortly.
tronixlabs: We will update the tutorial shortly.
That must deserve a karma!