Bluetooth HC-06

I'm using a Bluetooth HC-06, I know that its RXD pin must be supplied with 3.3v.
So I have seen that if I supply Arduino with 5v (thus each pin will have 5v), i must use a voltage divider, but in my project ( arduino + Bluetooth HC-06 ) I use a power supply of 3.7v ( thus each pin will have 3.7v).
So, do i need a voltage divider, or the tiny difference of 0.4v is okkey for the sensor?

thank you

You do not need a voltage divider if the only power supply is 3.7V and the whole system works at this voltage.

Yes, the whole system works at 3.7v and the datasheet says that RXD pin needs a 3.3 logic level.
So do you confirm that I won't damage the sensor ?

You will be amazed how many people use a 5v Arduino with HC-06 and have no problems. It IS a good idea to use the divider with 5v, but using one with 3.7v on Rx is being over cautious.

Fine thank you, I'll try without voltage divider for the RXD pin.
Another question : is it enough 3.7v for the Vcc of the sensor ? Because the datasheet says the RX e TX need 3.3v, but Vcc needs 5v !

Gee, I wonder which sensor that might be.......?
I guess if it says vcc 5v, that's what it needs, and the answer is "no". It may work but it might not be reliable.