Atheros AP81 reference design with USB & 802.11 b/g/n WiFi.

Some routers have U-boot 1.1.6 pre-installed which causes problems for OpenWrt. If you're owner of such device, read forum thread first. Some people were able to install OpenWrt by downgrading U-boot to 1.1.5 version.

WORK IN PROGRESS DO NOT FLASH IF YOU LACK SERIAL CONSOLE

You can download 10.03 build called openwrt-ar71xx-wrt160nl-squashfs.bin. After using it you will have to install kmod-ath9k to get WiFi working…

opkg install kmod-ath9k

…and to add wpa encryption if you plan to use it.

People who want more up-to-date OpenWrt may build a copy of trunk with the WRT160NL profile selected.

Can be flashed from Linksys web interface with file openwrt-ar71xx-wrt160nl-squashfs.bin

Set a PC on same network to some address in IP range 192.168.1.[2-254]. Download either Linksys or OpenWrt firmware image, store as code.bin. From serial console abort the U-boot process. Enter this on u-boot command line

ar7100> upgrade code.bin
check link duplex:Full/speed:100
dup 1 speed 100
Tftpd start listening on port[69]!
Load address: 0×80060000

Send file from windows PC with TFTP:

C:\tmp> tftp -i 192.168.1.1 put code.bin

For linux TFTP

 $ tftp 192.168.1.1 69
tftp> mode binary
tftp> put openwrt-ar71xx-wrt160nl-squashfs.bin

You should see this on console wait for flash to finish:

Receiving firmware [code.bin] from [192.168.1.10]
Write File : CODE.BIN

Once U-boot command prompt returns enter

ar7100 > go 

Pick one:

1. Flash using LuCI
2. sysupgrade -n openwrt-ar71xx-wrt160nl-squashfs.bin, as sysupgrade was added in Kamikaze trunk changeset 17202.
3. mtd write openwrt-ar71xx-wrt160nl-squashfs.bin

Preliminary support added in trunk changeset 16068. Switch code added in Kamikaze trunk changeset 17057. Sysupgrade feature added since trunk changeset 17202, enabling a firmware upgrade alternative. Various fixes & addition of profile resolved major issues by changeset 17249 and 17250.

Annotated photos available here

Model Number

Front:

Back:

Circuit Board - Front:

Circuit Board - Back:

Note: This will void your warranty!

• To remove the cover simply unscrew and remove the antennas, remove the 4 phillips-type screws on the bottom, and pry the case apart.
• There are no screws holding the PCB to the bottom cover once open.

Typical 3.3 volt TTL serial console present in 3 locations. The parameters are 115200 8-N-1

Location J3 on PCB with pin-header installed:

Initial successful efforts used a short Nokia DKU-5/CA-42 cable, these Atheros platforms seem to be difficult to work with using FTDI long cables.See more details here. EDIT - If you don't want to short your cable, use an old lynksys non-switching power adapter with transformer (switching adapters are generating noise which breaking serial console comunication)

There are duplicate serial console contact points inside WAN & LAN4 ports on PCB edge. You can modify an RJ45 plug with wires in the appropriate spots to access serial console without cracking open the case. Here is an example crafted by users retracile and EraZor:

There is a micro-JTAG connector present but so far no one has identified the header-size or attempted to access it.

The default network configuration is:

Port 4 is the internal/cpu port. Port 5 is probably unconnected.

If you forgot your password, broken one of the startup scripts, firewalled yourself or corrupted the JFFS2 partition, you can get back in by using OpenWrt's failsafe mode.

• Unplug the router's power cord.
• Connect the router's LAN1 port directly to your PC.
• Configure your PC with a static IP address between 192.168.1.2 and 192.168.1.254. E. g. 192.168.1.2 (gateway and DNS is not required).
• Plug the power on and wait for the DMZ LED to light up.
• While the DMZ LED is on immediately press any button (Reset and Secure Easy Setup will work) a few times .
• If done right the DMZ LED will quickly flash 3 times every second.
• You should be able to telnet to the router at 192.168.1.1 now (no username and password)

NOTE: The root file system in failsafe mode is the SquashFS partition mounted in readonly mode. To switch to the normal writable root file system run mount_root and make any changes. Run mount_root now.

1. Forgot/lost your password and you like to set a new one

 passwd 

2. Forgot the routers IP address

 uci get network.lan.ipaddr 

3. You accidentally run 'ipkg upgrade' or filled up the flash by installing to big packages (clean the JFFS2 partition and start over)

 mtd -r erase rootfs_data 

If you are done with failsafe mode power cycle the router and boot in normal mode.

There are 2 buttons. They are Reset and WiFi Protected Setup. The buttons can be used with hotplug events. E. g. [#wifitoggle WiFi toggle].

The supplied short dipole antennas can be easily replaced with large omni or directional antenna.

Original exploration thread https://forum.openwrt.org/viewtopic.php?id=20298&p=1

• CategoryModel 100MB Network with 4x1 ports USB Devices