This is my first attempt at a daemon to collect data from the SP-2101W and write a rrd file from it. It’s in C source and is tested to compile on Ubuntu and Fedora.
Warning: the daemon will query your device once per second, which makes the device become unresponsive after 2 days. I assume the web server fills up the log file system which causes something to crash. Use with caution, or change the default query interval to something like 5 minutes.