Running app_rpt on ASUS WL500

I’m running a project together with YO3KSR ham radio club in Bucharest. It aims at running app_rpt on an small WL500 router in order to make radio-VoIP-radio network. In the picture below one could see a router connected with a GM300 rig and the power supply for the rig. This article is just a short list of information on how to replicate the solution.

The router

It’s actually a WL500 Deluxe board together with a GPRS board (not used in this project) in a different box. It’s sold as Topex BYTTON GPRS.

The connections

Three USB connections are used:

– USB sound card – I’m using CM108 based card as of now but you may try a different card because I use chan_alsaradio driver.

– Mass storage flash card

– USB to RS232 converter for signaling (PTT and COR) – I’m not using the GPIO pins on the CM108 card because the requirement was to be able to use any kind of the USB sound cards that may not have GPIO pins.

The order of physical USB ports is important, it should be like in the picture. Otherwise you need to adjust configuration files.

Here is the connection board schematics for the PTT and COR:

The software:

The application is made to run on OpenWRT 10.03. You need to install it before attempting to install app_rpt.

Since the board has so less flash memory (4MB),  the USB flash drive is used to keep the new root filesystem.  In order to boot from flash drive you need to replace /sbin/init on your onboard flash filesystem with the following script: init. The script will switch from on-board flash root to the root mounted from USB flash drive.

Download the new root filesystem: from here

You need to make two partitions on the flash drive:

1. swap (~100M)

2. ext3 (the rest) – copy the content of the archive on this partition

Adjusting various bits:

Accessing the system after mounting USB root filesystem(user root, password admin): ssh root@

Changing the default IP address ( use your web browser and access the LuCI interface:

Adjusting audio levels: after you login with ssh use “alsamixer -V all”

Changing default node number (27237) and relation between node number and IP address: modify node number in /etc/asterisk/rpt.conf, and node number and IP in /usr/lib/asterisk/rpt_extnodes .

Inverting PTT signal: set invertptt=1 in /etc/asterisk/alsaradio.conf

Inverting COR signal: set carrierfrom=serialdsr or serialdsrinvert in /etc/asterisk/alsaradio.conf

Using the system:

Suppose you have two systems, first one with node number 27111 and the second with node number 27222. In order to dial from one node (27111) to the other:

*327222 from node 27111.

To disconnect: *127222.

You could configure and use any options app_rpt has.

Overclocking the router:

If the sound is chopped you may try to overclock the router . DO IT AT YOUR OWN RISKS!

For WL500 Deluxe:

nvram set clkfreq=264,132

nvram commit


I hope this is enough for someone to get started.

73, YO3IIU

6 thoughts on “Running app_rpt on ASUS WL500

  1. Hi Andrew,

    I am aware of GPIO pins of CM108. They could be used for any kind of IO operations.
    However, the driver chan_alsaradio I wrote for this project is made for a general USB sound card which may or may not have those GPIO pins available.
    That is why all signaling is done through serial line.


  2. Hi Bogdan,

    Good idea using a generic not-modified USB sound device!

    Do you think the WL500 will handle two USB devices with two radio channels?

    Did you have a problem with chopped sound (not enough CPU power) ?

    Thanks for your work on this, de ZL1BHD

  3. Hi, the WL500 is on the limit, probably it will not handle two radio stations in the same time due to the slow CPU. Though, I’m using WL500Pro, there is a Deluxe version with a powerful CPU, maybe it will be better.


  4. nvram set clkfreq=264,132

    HAS NO EFFECT WHATSOEVER on the cpu frequency. You can’t overclock an Asus wl-500g Deluxe.

    If you don’t belive me, you can read Oleg’s remarks in Russian language:

    “Никак. Процессор wl500g deluxe работает на фиксированной частоте. Да и смысла нет.”

    “Nothing. Processor wl500g deluxe operates at a fixed frequency. And it makes no sense.”

    This command “nvram set clkfreq=264,132” has been advertised to work by the second hand vendor of these routers, to be able to sell you.

    You can also try:
    cat /proc/cpuinfo

  5. I agree with you partially.

    Indeed what the /proc/cpuinfo shows is the same before and after you execute the command. However, on my experiment, after executing the command the sound is not chopped anymore. That make me think the command DOES something good. Sorry I did not investigate what exactly the command is doing but if it helped, I used it.


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