Maplin A26LW A5-V11/A5-V12 OpenWrt Ralink RT5350F Mini Portable 150Mbps 3G/4G WiFi Wlan Hotspot AP Client RJ45 USB Wireless Router

So while randomly browsing a deals website I came across a USB wifi router/hotspot on sale at Maplin for a mere £2.00 and as my tinkering desire took over I decided to order a couple.

These devices all appear very similar physically but your mileage my vary on functionality i.e they may have
A restricted bootloader that doesn’t allow OpenWrt images
Limited Busybox shell available by telnet
More complete Busybox shell

Board is marked A5-V12 and chip is an Ralink RT5350F. From my reseach I found other boards are marked A5-V11 so used that as a starting point.

SoC RT5350
Clock 239 MHz
4 MByte Flash (GD25Q32)
16 MByte RAM (EM639165TS-6G)
USB Host 2.0
10/100 Ethernet switch
802.11n interface
Reset button
2 LEDs
Micro usb as power source

For this configuration I used my windows desktop and connected my 2nd network interface to the device.

Default ip is and DHCP is enabled

Telnet is enabled by default and can login using admin/admin

BusyBox v1.12.1 (2011-10-22 23:04:50 CST) built-in shell (ash)
Enter 'help' for a list of built-in commands.

# help

Built-in commands:
. : break cd chdir continue eval exec exit export false hash
help local pwd read readonly return set shift source times trap
true type ulimit umask unset wait

# cat /proc/cpuinfo
system type : Ralink SoC
processor : 0
cpu model : MIPS 24K V4.12
BogoMIPS : 239.61
wait instruction : yes
microsecond timers : yes
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : yes
ASEs implemented : mips16 dsp
VCED exceptions : not available
VCEI exceptions : not available

cat /proc/cmdline
console=ttyS1,57600n8 root=/dev/mtdblock5

# cat /proc/mtd
dev: size erasesize name
mtd0: 00400000 00010000 "ALL"
mtd1: 00030000 00010000 "Bootloader"
mtd2: 00010000 00010000 "Config"
mtd3: 00010000 00010000 "Factory"
mtd4: 000c282a 00010000 "Kernel"
mtd5: 002ed7d6 00010000 "RootFS"
mtd6: 003b0000 00010000 "Kernel_RootFS"

The stock bootloader is minimal/strangled one and needs upgrading and doesn’t allow flashing of OpenWrt firmware via the stock gui.

The easiest way to load a new bootloader and firmware is to download the files from a webserver. I used miniweb after installing I added the following files the htdocs directory


and then run via windows command line

C:\Users\pc\Desktop\miniweb>miniweb.exe -p 80 -d
MiniWeb (build 300, built on Feb 28 2013)
(C)2005-2013 Written by Stanley Huang

Web root: htdocs
Max clients (per IP): 32 (16)
URL handlers: 2

Back in your telnet window download the two files

cd /tmp
# wget
Connecting to (
uboot_usb_128_03.img 100% |*******************************| 135k --:--:-- ETA

# wget
Connecting to (
firmware.bin 100% |*******************************| 3328k 00:00:00 ETA

Next write the new bootloader

# mtd_write write /tmp/uboot_usb_128_03.img Bootloader
Unlocking Bootloader ...
Writing from uboot_usb_128_03.img to Bootloader ... [w]

Now write the new firmware

# mtd_write write /tmp/mini.bin Kernel_RootFS
Unlocking Kernel_RootFS ...
Writing from /tmp/mini.bin to Kernel_RootFS ... [w]

Once all complete reboot
# reboot

While it's rebooting you'll need to set a static ip on your desktop interface that is connected to the device i.e

Once the deivce has rebooted it will be available via and again telnet is enabled.
=== IMPORTANT ============================
Use 'passwd' to set your login password
this will disable telnet and enable SSH

BusyBox v1.19.4 (2013-12-29 15:07:06 UTC) built-in shell (ash)
Enter 'help' for a list of built-in commands.

_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
BARRIER BREAKER (Bleeding Edge, r35407) - RT5350F
-- Cooked by pratanczuk --
-- --
-- --

CONGRATULATIONS you now have a minimal OpenWrt image installed. You can now also upgrade using the sysupgrade function but you need to be aware of the 16MB memory limit.

Please let me know what you are using your devices for and share any custom f/w you've built for it.

Here are some useful links I found
My Embedded (minimal OpenWrt image)
Blog Post

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1 Comment

  1. As these devices have so little free RAM once OpenWRT is up, I found the sysupgrade utility doesn’t work if the update image is copied to /tmp. The solution is to pipe the image via ssh directly into mtdwrite. From a fresh build of OpenWRT:

    cat bin/targets/ramips/rt305x/openwrt-ramips-rt305x-a5-v11-squashfs-sysupgrade.bin | ssh root@ ‘mtd write – firmware’


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