The APC Master Switch series PDUs have an RJ11 socket for the serial port, if you have a spare Cisco serial cable lying about here is a quick trick to make up a 9 pin D-Type socket to RJ11 plug cable: Cisco Pin Colour RJ11 Pin Description 1 Grey CTS 2 Blue DSR 3 Green […]
Hardware
M590E hardware mods
The M590E is a 2G GSM module that, at the time of writing, can be bought as a kit on eBay for around £1 complete with PCB and components.