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Topic: tp-link 3420 hw 1.1 serial problem

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Hi. I have problems with the serial and tp-link 3420 hw 1.1.
I soldered gnd tx whit 10k resistor but when I enter in putty the serial sends me text illegible. any suggestions?

Assuming you have checked your connections, and the connection is TTL (usually 3v3, sometimes 5v) have you read this:
http://wiki.openwrt.org/toh/tp-link/tl-mr3420

You need the correct connection speed.

yes. everything is ok in the settings

Can you give a sample output? If it is total gibberish, your speed might be wrong.
Also, is it possible to disconnect the router, short the TX and RX on the PC and see if you get a proper echo.

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with 9600 baud rate

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with 115200 baud rate

I can't find anything wrong sad

what adapter are you using?

prolific usb to serial..

r u sure it's a ttl 3v3 ??

anyway prolific is a brand that makes tons of different chips..

(Last edited by nebbia88 on 30 Apr 2013, 15:45)

No he isn't, I think I got the same adapter it spews out arround 5v.

So there is a chance the rs232 of the router is still functional, but you do need a level shifter to not blow up the routers rs232/comport.
see http://wiki.openwrt.org/doc/hardware/po … ter.module

(Last edited by FriedZombie on 30 Apr 2013, 15:50)

also, given the correct converter, only connect Tx Rx and maybe Gnd, NOT Vcc

"maybe gnd"?? without gnd it's really hard it will work xD

I connected tx , rx ,vdd (the tx and gnd are connected with the resistance 10k) and I turned on the router by connecting the power.
(the serial chip has the pl-2303)
Someone tell me where I'm wrong?

(Last edited by shakle on 2 May 2013, 00:02)

1. You only connect Tx, Rx and GND of the router with your serial converter.
2. The 10k resistor needs to be placed between Tx and Vcc (3.3V).

apologizes, resistance is connected between Vcc and Tx. I connected Tx, Rx and GND but these are written:
ðþÿÿüÿüþÿþøüøÿ
sad

Do not connect Vcc.
Tx and Rx on the router should be connected to Rx Tx on the connector,
ie Tx-to-Rx etc.
Obviously Gnd goes to Gnd.

is what I did.. hmm

I get blu screen with a driver error: ser2pl64.sys. (windoes 7) . I tried serial power 3.3v and 5v. Probably the connections are affixed. Is it an error driver? How can i do?

(Last edited by shakle on 7 Apr 2014, 09:20)

Try with linux

I use debian. which software should I use for the serial?

picocom, minicom...

i wrote chmod 666 /dev/ttyUSB0 in console and used putty..
I got same strange character..

Try to resolder serial console and reinstall driver. Maybe you must try with different 10k resistor or test this one with multimeter. Seems that the problem is in TTL adapter

Good luck !

can you post pictures of your setup? pins, cables, adapter, including adapter chips if they are readable wink

where the green cable goes? you don't need vcc from adapter!

the resistor usually is needed between tx and vcc pin of router.

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