Hi, i have connected my hc-05 to arduino nano like:
gnd --> gnd
5v --> 5v
rx --> tx
tx --> rx
So, now the problem is that rx led on arduino nano is on constantly, all alimented WITH BATTERY (4x 1.2V) on the 5v pin. But if I try with usb cable rx don't light and works perfectly...
Can somebody helps me? and i think the problem isnt the 4x 1.2V batteries though 4x1.2 = 4.8V is under 5V... becuase i tryed with 4x 1.5V and the problem persist...
I assume you are talking about the Rx light on the Nano. Check if you are getting noise. You can ground the Rx pin via a 1K resistor and it should stop. Not knowing your circuit be careful so you do not short anything.
Yes, I'm talking about the Rx LED on the Nano.
the hc-05 is connected:
rx -> tx
tx -> rx
5v -> 5v
gnd -> gnd
I power the Arduino nano with 4 batteries (1.4v each) on the 5v pin and then the GND on any GND of the nano. You say to take the Rx pin (of the nano board) and connect it to the gnd fed with a 1k resistor?
Yes and see if that changes the problem. If you have a scope or logic analyzer check the signal coming into the Rx pin. If the USB is connected disconnect it.
From the frizzy pictures there are many items connected, I await the schematic so I can help you. Be sure to include links to technical information on each hardware device.