MR3020

is a TP-LINK router with a single antenna non-detachable antenna and a USB port. As of this moment, this is one of the smallest routers available.

MR3020 v1.x

The package contains the router, a power supply, a USB-A to USB-mini cable.

Note that this router has default IP 192.168.0.254

Hardware characteristics

CPU	Atheros AR7240 @ 400 MHz
RAM	32MB
Flash	4MB
WAN or LAN	1x 100Mbps Auto MDI/MDIX
WiFi	802.11 b/g/n 150Mbps (130Mbps real) 20dBm - 100mW

Power characteristics

This router uses a 5V power supply, rated 2A. Its consumption was measured and is up to 120mA in normal operation - about 600mW, 180mA+ during boot. There appears to only an internal voltage regulator for the router, USB port is powered directly from the power supply.

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

PoE

Passive PoE injection is feasible by some soldering. Do the following:

• Bottom side: Remove C45, R71, R68, R65, R64 (located near ethernet connector pins)
• Connect the two pins with tracks to R65 with a piece of wire to rightmost of 4 pins at USB host connector (the one towards the center of the board)
• Connect the two pins with tracks to R68 with a piece of wire to leftmost of 4 pins at USB host connector (the one towards to the edge of the board)

If you PoE is not 5V, consider using a step-down power regulator. For example:

• LM2596 DC Converter Power Supply Buck Step Down Regulator can be set to 5V up to 1.5A (3A with heatsink) (available on ebay)

Restoring to original firmware

TODO

Disassembly

Opening migh prove to be difficult, because the lid is glued into place. You can cut around the edge first then open it.

Openwrt LED diode configuration

/etc/conf/system

config led 'led_usb'
        option name 'USB'
        option sysfs 'tp-link:green:3g'
        option trigger 'usbdev'
        option dev '1-1'
        option interval '50'

config led 'led_wlan'
        option name 'WLAN'
        option sysfs 'tp-link:green:wlan'
        option trigger 'phy0tpt'

config led 'led_lan'
        option name 'LAN'
        option sysfs 'tp-link:green:lan'
        option trigger 'netdev'
        option dev 'eth0'
        option mode 'link tx rx'

USB

There is already a USB connector.