There are various articles describing how to install and run Debian GNU/Linux on USB flash memory on an Asus WL-500W. This guide differs in that it will provide a complete end-to-end set of instructions. All you need is an Asus WL-500W, USB flash memory (say, 2 GB in size), a computer to build the firmware and Debian root filesystem, and an Internet connection to get the source code for OpenWRT and packages for Debian.
My Roomba 560 seemed shy as it was backed into a corner with a dead battery every time I came home. So, as I had done many times before, I cleaned all the LED sensors under the bumper and fitted a new battery. No change. I eventually found this site about the nine beep dance of death. Ah, more dust in the sensors, I thought. Testing showed the faulty right bumper switch. Taking it apart I was pleasantly surprised by the use of optical rather than mechanical switches. Still, dust could still be a problem.