Adventures in development, circuits, creativity, and questionable life choices.
As I was dabbling in some POTS hardware and PBX systems, I was on the lookout for analog telephone adaptors.
By chance, a fellow member of our local hackerspace happened to have a cleanout session at work.
Among the "things to be thrown out" were a couple of Cisco ATA186 analog telephone adaptors.
The PSU's were missing, but since they're just standard 5 volt DC PSU's, it's fairly trivial to build one from a standard USB-A brick.
These adaptors just require 5 volts and 2 amps, so a common, somewhat decent brick should suffice.
Of course, by default, these devices run the so-called "SCCP" or "skinny" firmware which is used for Cisco's proprietary phone manager and PBX systems.
Since my plan is to use them with open source PBX systems, I would much prefer to use SIP (Session Initiation Protocol).
That way, these old devices which many regard as "e-waste" now can still be useful in some setups.
As it took me a while to figure out how to flash these devices, I'm writing this blog post to share the (somewhat surprisingly easy) method to do just that.