Confusion about serial connection on asus rt-ac58u

Hardware Questions and Recommendations
1

The serial connection info for asus rt-ac58u mentions Only the GND, Rx and Tx pins need to be connected. here

I have ordered this usb-uart device : PL2303 PL2303HX USB To TTL(Serial) Converter Module – 5 Pin

But i cant figure out how would i select the 3.3v from this device? If only GND,Rx,Tx need to be connected on the serial interface on the router, what connection would specify that the uart device needs to work on 3.3v ?

Thanks.

2

use a voltage divider inline with the (uart-dongle) tx pin to ground...

from the product description sounds like there are only v-out(3/5)

3

can you please explain a bit more?
Does it mean, i need to do some additional circuitry? before i can use this dongle?

4

yes... read the link above... it is all explained there... ( or run a general web search for 10000 similar links / descriptions )

5

@anon50098793 i dont intend to build another circuit, even if its a small one.
Can you help me in selecting another dongle?

if i order this one: https://robu.in/product/cp-2102-6-pin/
It says, it switches to 3.3v when jumper is used to connect 3.3v pin to gnd.
So with this configuration, i guess, i would need to connect the dongle to serial interface as follows:
dongle pins : serial pins
gnd->gnd
txd -> tx
rxd -> rx
would this be correct?

6

I dunno maybe I'm mistaking... i don't like these chipsets but the picture show some sort of 'shunt'... which may be possible with either device you mentioned...

best to wait for other users who have experience with these devices I think...

this one specifically states 3.3v logic levels

7

@ashjas You quoted it yourself from the wiki: it should not be connected. Note how the wiki states you should only connect the other pins.

You do not need to power the device, hence you do not need to connect the voltage pin.