which made me think that the power button on the PC doesn't actually require a relay. If I understand correctly, just closing the circuit gives a signal to the motherboard to turn the computer on or off.
Is there a way to simulate this using the Arduino only? Do I need a relay for this type of setup?
opkg updateopkg install etherwake
etherwake -i eth1 00:1d:09:2e:36:93
shutdown.exe /s /t 00 #Windows Vista, 7, and 8 users
shutdown -h now #linux
Wake-on-LAN by Arduino Yun/compatible
Also, you must allow the system to boot into the OS (windows in my case) and then perform a proper shut down. if you you just hold the power button down and kill the system or pull the power plug wol would not work
From that referenced page:The OP is experiencing power failures, and wants to be able to remotely restart the computer when that happens. Since a power failure is not a graceful shutdown and is equivalent to pulling the power plug, it sounds like WOL may not help him?
At System BIOS set up AC Power Recovery:On, Now box will be auto restart once power back. Some time this setting is well hidden. I sometime found it under security section of BIOS.The Wol setting is at NIC BIOS.AC Power Recovery:OnOffLast
You don't need a relay to do this, it can be done with a transistor. But using a relay is a lot simpler and safer as you don't have to worry about voltages, polarity, and common grounds. The coil of the relay is controlled by the Arduino (and you will probably need a transistor to drive the relay coil.) Then the normally open contacts of the relay are wired in parallel with the contacts of the power switch. You are essentially doing the same thing as in the video, but you are using the contacts of the relay instead of the pushbutton switch.
You could also take a USB cable with one end plugged into the computer, and the other end snipped of
When a PC is configured to wake on LAN, it MUST continue to have standby power, and network connectivity all the time. If there is a power failure, or a network outage (restarting a switch or router is enough, it acts like disconnecting the network cable from the PC's NIC), then the PC will not respond to magic packets until after being booted into Windows and gracefully shutdown again (as you mentioned you are doing).This is a well-documented limitation in Wake on LAN. I'm not sure if this is by design, or just something that couldn't be avoided for some reason- but I can repeat the problem on my PCs too.
When I tried to read on the WOL option, it stated that WOL works only if the computer is hibernating or sleeping. I do want to be able to do a full shutdown and startup....
The huge difference between read and do! It does work fine with full shutdown and startup