Powering on a second Pi

[SkyFox]

Sorry in advance, I'm a noob. I'm looking for a way to have my Pi model B+ power up a Pi 2 on demand. I've read that wake on LAN isn't supported so I was wondering if anyone knew of a way to connect the Pi's together or a device that could be used to cut power from the second pi via a command from the first?

I need a solution that doesn't require 24/7 extra power ideally (which rules out WIFI power sockets etc)

I was thinking maybe it's possible to connect both a power cable and the B+ (via USB) to the Pi2's microUSB socket via some kind of splitter... Have the USB ports on the B+ disabled at all times as I don't use them, then turn the ports on for a second or so to start the Pi2 booting. I very much doubt something like this would work as I think the cable needs to be fully removed and reinserted to start the Pi booting?

Any idea's

Thanks

[fsr]

Well traditionally power is switched with a relay.

you'd need 1 gpio pin (+gnd) to toggle something like this which then controls the 5v power line going to the rPi2

I need a solution that doesn't require 24/7 extra power

i don't understand what you mean here.

[SkyFox]

i don't understand what you mean here.

I just meant that Ideally I didn't want a solution that requires another device which consumes power waiting for a signal. A WIFI plug for instance would be permanently connected to WIFI and therefore using power at all times waiting for a command. I was looking for a solution that didn't require any extra power until the B+ decided to turn on the Pi2.

Appreciate the response, I'll look into your suggestion, I'm a complete noob but it looks like a good opportunity to learn

[klricks]

i don't understand what you mean here.

I just meant that Ideally I didn't want a solution that requires another device which consumes power waiting for a signal. A WIFI plug for instance would be permanently connected to WIFI and therefore using power at all times waiting for a command. I was looking for a solution that didn't require any extra power until the B+ decided to turn on the Pi2.

Appreciate the response, I'll look into your suggestion, I'm a complete noob but it looks like a good opportunity to learn

You could use an 'off the shelf' relay board.
If you want to do this as a learning experiment then OK however I fail to see the point having one RPi power on another nearby RPi?
Also IMO a RPi draws so little power that there is no point in powering down either RPi.

[SkyFox]

Thanks klricks, could be exactly what I need.

It is a learning experiment yes as the cost of parts could probably power the Pi2 for a year or more . The Pi2 would only be used a few times per week for VPN (until I give it more tasks) so even though the power draw is small I like the idea of being able to remotely power it on and off. The B+ already has a number of jobs and never gets powered down. I thought about migrating the B+ tasks to the 2 but... I like my B+ heh.