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Raspberry Pi 2 and Wake On LAN

Posted: Sat Mar 14, 2015 11:02 am
by dchapma1
I rob ably already know the answer to this but I have not found and definitive answer concerning the Pi 2. So - does the new Raspberry Pi 2 support Wake On LAn. If not, is there a hack that can be done to get this all important feature working?

As powerful as the RPI is I cannot believe it does not support WOL.

Thanks,

Don

Re: Raspberry Pi 2 and Wake On LAN

Posted: Sat Mar 14, 2015 11:07 am
by fruitoftheloom
dchapma1 wrote:I rob ably already know the answer to this but I have not found and definitive answer concerning the Pi 2. So - does the new Raspberry Pi 2 support Wake On LAn. If not, is there a hack that can be done to get this all important feature working?

As powerful as the RPI is I cannot believe it does not support WOL.

Thanks,

Don
The RPi2 B uses a combined USB/Ethernet Chipset on the USB Bus, same as the RPi1 B+, and WoL has not been implemented, nothing has changed since the original RPi1 B was released 3 years ago:

http://www.microchip.com/wwwproducts/De ... ct=LAN9514

http://www.raspberrypi.org/forums/viewt ... 28&t=95640


Hope you can believe that WoL is not supported ;)

Re: Raspberry Pi 2 and Wake On LAN

Posted: Sat Mar 14, 2015 11:51 am
by DougieLawson
dchapma1 wrote: As powerful as the RPI is I cannot believe it does not support WOL.
Why do you need WoL when it costs pennies to run a Raspberry Pi 24/365.

At 5V 1000mA, that's 5W so for a year that 43.8kWh. 1kWh costs around £0.10 [1], so it's no more than £4.38 per year to run a RPi. Except that it doesn't draw anywhere near 1000mA most of the time.

[1] http://www.ukpower.co.uk/home_energy/ta ... r-unit-kwh in the Land of the Free your energy costs are lower.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Fri Apr 17, 2015 11:55 pm
by orchard800
Why do you need WoL when it costs pennies to run a Raspberry Pi 24/365.
When you're running it on battery power in, say, a robot setup. WOL would be the obvious solution.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Sat Apr 18, 2015 12:03 am
by mahjongg
why is WOL an obvious solution, it costs energy to keep a WOL system up, thats why WOL systems on PC's use about the same amount of energy when "waiting", as a PI uses running.
There is no lower power mode that keeps the PI running and the ethernet adapter powered, than letting it just run.
lower power can only be realized when you turn of both the CPU, and the LAN9512 chip.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Sat Apr 18, 2015 2:36 pm
by orchard800
Fair enough. I assumed the board and processor would use less power when switched off but you make a good point. Thanks.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Thu May 21, 2015 7:53 am
by Tom_A
orchard800 wrote:Fair enough. I assumed the board and processor would use less power when switched off but you make a good point. Thanks.
You might be able to get a little lower power usage by setting lower minimum processor and gpu speeds in the config file, but I doubt you will get much.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Thu May 21, 2015 10:41 am
by texy
[SNIP]
Removed off topic posts.
Texy

Re: Raspberry Pi 2 and Wake On LAN

Posted: Thu May 21, 2015 1:24 pm
by solar3000
the pi still uses 110mA when "off". So if you are running on battery, you need to have a physical off switch. or a relay or a solid state relay or a transistor.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Tue Jun 02, 2015 8:11 pm
by solar3000
actually there is a good reason for wanting WOL for RPi.
If there was a power outage it may not turn on (usually it starts up again).
Or if it was remotely shutdown.

Re: Raspberry Pi 2 and Wake On LAN

Posted: Thu Jun 04, 2015 2:59 am
by Tom_A
solar3000 wrote:actually there is a good reason for wanting WOL for RPi.
If there was a power outage it may not turn on (usually it starts up again).
Or if it was remotely shutdown.
If there's a power failure and it doesn't come back up when the power comes back on then it's not likely it's going to work right until you have a close look at it. There's probably corruption to the file system that needs to be repaired or you might need to reinstall, hopefully from a back-up.

As far as shutting down goes, well... Don't do that! Not unless you really know you don't want it on until you have not so remote access to it.

I suppose if you had two with some sort of relay hats, you could use the relays to trigger a restart from the opposite Pi. :D
Here's the thing about WOL. It's "Wake On LAN." It doesn't work well or at all over WAN. Most if not all routers block it, so you need a machine that is local to the one you want to wake to send the WOL signal. There's a web interface for the Pi written to to exactly this (although it runs on any web server).