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

1. → obtain.firmware
2. → Install OpenWrt

OpenWrt 10.03 has problems with ath9k driver and newer devices shipped with U-boot 1.1.6. These problems are resolved in RC version of OpenWrt 10.03.1. It seems installing 10.03.1 (even in RC stage) provide better stability than final version of 10.03.

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 update; opkg install kmod-ath9k
rm -rf /etc/config/wireless; wifi detect > /etc/config/wireless

…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 the original 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 (openwrt-ar71xx-wrt160nl-squashfs-factory.bin), 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 -m binary 192.168.1.1 69
tftp> put code.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

→ generic.sysupgrade

In trunk changeset 17202 sysupgrade got enabled for the WRT160NL.

cd /tmp
wget ...
sysupgrade -n openwrt-ar71xx-wrt160nl-squashfs.bin

The sysupgrade -n command line switch tells sysupgrade to not keep the configuration files.

cd /tmp
wget ...
mtd -r write /tmp/openwrt-ar71xx-wrt160nl-squashfs.bin firmware

→ Basic configuration After flashing, proceed with this.
Set up your Internet connection, configure wireless, configure USB port, etc.

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

Note that port 5 on the internal Ethernet switch is not connected to or used for anything.

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.

The programmer needed to access the SPI flash through the Jtag points is a USBJTAG NT from http://www.usbjtag.com/.

The JTAG should be 2mm spacing. IR length 5 The pinout is the same as regular 14 pin JTAG.

To read the flash you need to send a poke command bf000000,1 (using TJTAG) not needed in NT software as it is already implemented. Programming can only be done by USBJTAG NT for now.

http://www.usbjtag.com/jtagnt/router/wrt160nl.php shows a rough connection to Jtag points. More information can be found on the USBJTAG forums.

The default network configuration is:

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

→ generic.failsafe

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