Note: Many of these routers are marketed as a “3G travel router” but none actually include a 3G 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…
This section deals with how you install OpenWrt from a device freshly opened. Plus the steps required such as reset to factory defaults if the device has already been configured
Note: Reset router to factory defaults if it has been previously configured.
Browse to http://192.168.1.1/Upgrade.asp
Upload .bin file to router
Wait for it to reboot
Telnet to 192.168.1.1 and set a root password, or browse to http://192.168.1.1 if LuCI is installed.
Note (dated 20140424)
A TP-Link TL-MR13U received from AliExpress is TL-MR13U v1 00000000 hardware and has firmware 3.17.1 Build 130705 Rel.37118n. The link for firmware upgrade is now http://192.168.1.1/userRpm/SoftwareUpgradeRpm.htm, however loading that link directly will result in “You have no authority to access this router!”.
To access the upgrade page, select the last menu entry on the left of the page (which reads as http://192.168.1.1/userRpm/DateTimeCfgRpm.htm when you hover over the link), and then select the third entry in the sub-menu http://192.168.1.1/userRpm/SoftwareUpgradeRpm.htm.
That menu position is shown by the mouse-cursor position in the following picture:
If you have already installed OpenWrt and like to reflash for e.g. upgrading to a new OpenWrt version you can upgrade using the mtd command line tool. It is important that you put the firmware image into the ramdisk (/tmp) before you start flashing.
LuCI Web Upgrade Process
Browse to http://192.168.1.1/cgi-bin/luci/mini/system/upgrade/ LuCI Upgrade URL
Upload image file for sysupgrade to LuCI
Wait for reboot
Terminal Upgrade Process
Login as root via SSH on 192.168.1.1
Use the following commands to upgrade.
If sysupgrade does not support this router, use the following commands.
mtd write /tmp/xxx.abc linux && reboot
Back to original firmware
Download the latest firmware http://service.tp-link.com.cn/detail_download_1226.html unpack the archive. You should have mr13uv1.bin inside it. This file has little over 4MB so it contains a bootloader. You can't flash it directly from OpenWrt web interface or through ssh and mtd command. First you have to strip the .bin file of the bootloader. For this you use a tool called dd.
Type your root password when prompted and a slow upload will start.
SSH to your router and perform the following commands:
Flash via mtd
mtd -rwrite/tmp/mr13uv1_noboot.bin firmware
This should reboot the router after writing is finished. If it reports an error DO NOT restart the router because you will brick it. Instead check again if you used the right firmware which should have 3932160 bytes.
→ Basic configuration After flashing, proceed with this.
Set up your Internet connection, configure wireless, configure USB port, etc.
The default network configuration is:
LAN & WiFi
LAN ports (1 to 4)
Switch Ports (for VLANs)
Numbers 0-3 are Ports 1-4 as labeled on the unit, number 4 is the Internet (WAN) on the unit, 5 is the internal connection to the router itself. Don't be fooled: Port 1 on the unit is number 3 when configuring VLANs. vlan0 = eth0.0, vlan1 = eth0.1 and so on.
The TP-link MR13U have one button and two sliders.
Button is used for battery status.
One slide switch for on/off and the second is used in stock firmware to set different modes.
Mapping in openwrt for mode slider:
There are 30 GPIO pins on ath79 with the following values as default:
gpio-0 (sysfs ) in lo
gpio-1 (sysfs ) in lo
gpio-2 (sysfs ) in hi
gpio-3 (sysfs ) in lo
gpio-4 (sysfs ) in lo
gpio-5 (sysfs ) in lo
gpio-6 (sw1 ) in lo
gpio-7 (sw2 ) in hi
gpio-8 (sysfs ) in lo
gpio-9 (sysfs ) in hi
gpio-10 (sysfs ) in hi
gpio-11 (reset ) in lo
gpio-12 (sysfs ) in hi
gpio-13 (sysfs ) in hi
gpio-14 (sysfs ) in lo
gpio-15 (sysfs ) in lo
gpio-16 (sysfs ) in lo
gpio-17 (sysfs ) in hi
gpio-18 (USB power ) out hi
gpio-19 (sysfs ) in lo
gpio-20 (sysfs ) in lo
gpio-21 (sysfs ) in lo
gpio-22 (sysfs ) in lo
gpio-23 (sysfs ) in lo
gpio-24 (sysfs ) in lo
gpio-25 (sysfs ) in lo
gpio-26 (sysfs ) in lo
gpio-27 (tp-link:blue:system ) out lo
gpio-28 (sysfs ) in lo
gpio-29 (sysfs ) in lo
MR-13U has a rather big battery therefore it takes a long time to charge it. It might seem for the first time that nothing happens after connecting a charger. The router has 6 leds of which 4 blue and 1 red are used to indicate the battery status. When you press the battery button status LEDs light up.
When the battery charging is in progress LEDs stay on and after it's finished they go off. While charging the router consumes about 7W (measured with watt meter in power outlet)
If the battery level is low one red LED light up and stays this way even if the battery check button is released.
Update: First charging via notebook USB port with router powered on all the time took almost 40 hours
Iperf tests average rate was ~60 Mbps with peaks at 70 Mbps (7.6 - 8 MB/s) using ralink USB client device with rt2800usb driver.
Forum member pepe2k made a modification of U-Boot 1.1.4 for Qualcomm Atheros SoCs based devices (the project is still being developed, so new devices and SoCs will be supported in the future). Up to date information, binary images and sources can be found on official GitHub repository.
This modification started from wr703n-uboot-with-web-failsafe project, but supports more devices, all modern web browsers, has a lot of improvements and other modifications (like U-Boot NetConsole, custom commands, overclocking possibilities etc.).