Power management.

To extend the life of the internal batteries we can suspend the computer. Waking the machine is the trick though. BIOS doesn’t support power resume (but we could try the capacitor trick) but it does support Wake On LAN. Possibly configure the Arduino with an ethernet shield to do this at intervals.

http://www.debian-administration.org/articles/122

http://yutakalifenet.up.seesaa.net/html/wolRepeater.html

rossetti@waikato:~$ sudo aptitude install ethtool
rossetti@waikato:~$ sudo ethtool eth0
Settings for eth0:
Supports Wake-on: pg
Wake-on: d
Current message level: 0x00000000 (0)
Link detected: no
rossetti@waikato:~$ sudo ethtool -s eth0 wol g
rossetti@waikato:~$ sudo ethtool eth0
Settings for eth0:
Supports Wake-on: pg
Wake-on: g
rossetti@waikato:~$ /sbin/ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:24:8c:29:67:44

There are several pieces of software for sending the wakeonlan packets inside the Debian archive:

  • etherwake
    • Requires root privileges and available in all Debian distributions.
  • wakeonlan
    • Can be used by all users, but only in the Sarge (testing) and unstable (Sid) repositories

I’m going to use wakeonlan, since it’s already installed and can be used by non-root users:

skx@mystery:~$ wakeonlan  08:00:20:C2:1E:F6 
Sending magic packet to 255.255.255.255:9 with 08:00:20:C2:1E:F6