Last modified 8 years ago Last modified on 10/19/2011 06:07:21 PM


TP-LINK WR841ND is a dual-antenna 2x2MIMO router, that represents the main difference from WR741ND version.

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WR841ND v7.1

Some technical characteristics:

  • 1xWAN, 4xLAN 100Mbps
  • dve odstranljivi anteni RP-SMA
  • 32MB ram , 4MB flash, 400MHz
  • serijski vmesnik, USB vhod na čipu
  • napetostni regulator MP1482 - 3.3V 2A (vhodna napetost 4.75V do 18V) - učinkovitost do 93%


Serial interface

There is a serial interface connector on the router board and it requires a pull-up resistor for TX.

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PINOUT The serial connector is loacted on the left side of the board (looking from front), there are 4 empty holes. The thick white line marks TX.


Pull-up resistor should be about 10kOhm, but the exact value is not critical.

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Serial interface an then be used with a serial cable?.



Connection can be established with the following settings on OS X or Linux:

cu --parity=none -s 115200 -l /dev/(your serial device)


The router can be upgraded/fixed with a TFTP method, although its use should be avoided if possible. A working serial cable is required.


  • connect to the serial interface
  • expect Autobooting in 1 seconds

write tpl within a second

  • set ip of the router and computer (has to have a static IP)
setenv ipaddr
setenv serverip
  • start tftp server on your computer and include the desired firmware in its path
  • run the following commands
    ar7240> tftpboot 0x80000000 openwrt-ar71xx-tl-wr841nd-v5-squashfs-factory.bin
    ar7240> erase 0x9f020000 +0x3c0000
    ar7240> cp.b 0x80000000 0x9f020000 0x3c0000
    ar7240> bootm 0x9f020000
  • router will reboot and start with the new firmware