Picture of impBoot: Remotely Turn on a Desktop Computer
While at school, I found myself needing to remote desktop or SSH into my computer quite frequently. I would send MATLAB scripts to run while I was in class or working on something else. I needed to either leave my desktop running (sucking around 200W while idle) or find a way to turn it on remotely. Wake-on-LAN (WoL) works quite well but requires a wired, Ethernet connection, and try as I might, I could not get Wake on Wireless LAN (WoWLAN) to work with my hardware. 

The Electric Imp with a simple switch allows for a different kind of Wake on Wireless LAN as long as you have WiFi access and a USB port that always provides power (even when the computer is off). This instructable is fairly straightforward but assumes you are comfortable soldering and stripping wires.

Step 1: Equipment

Picture of Equipment

* Electric Imp
* Electric Imp Breakout (with male headers soldered to all ports)
* 3x Female-Female jumper wires
* Breadboard
* 1kΩ resistor
* 2N3904 (NPN Transistor)
* USB-mini cable
* 4x wires (22-26 ga. stranded), each about 4 feet long (both ends stripped and tinned)
* Android smartphone (if you can replicate Electric Imp Toggle functionality, Android isn't needed)


* Wire strippers
* Soldering iron
* Solder
* Flux
* Wet sponge
mattkerns7 months ago
Is it possible to get the 24 wire cheaper in say a 20ft instead of 75 ft. If so where can i buy shorter lengths.

home depot sells it in rolls, or you can buy it by the foot.

rrsquez9 months ago

Excellent project!

Ah-che1 year ago

Is there a version for new IDE of Electric imp ? there is no more Planner :)

Supay2 years ago
This is an excellent idea, particularly as I have issues with my WoWLAN working as well and since I had to shift my PC location I no longer have access to an Ethernet connection.

I'd also be very interested in seeing if I could get this working to switch the mains socket on/off remotely as well as the PC, as I find that my PSUs still draw 40W or so even when the PC is switched off. It all adds up!
ShawnHymel (author)  Supay2 years ago
I thought about this as well - you would have to hack up a power strip and put a relay in line with the power wires. It should work....just a bit more work. I might play around with it, as then you would have an Internet-controlled power switch to just about anything.

And wow....I didn't know that the PSUs still draw so much when off!
bprins2 years ago
By default most PC's come with a wake on LAN feature built into the board. The board will hold a small enough charge to take replies from your network router. You could just port forward on your router for the packets to come through. Six bytes of 0xff, then its own MAC address 16 times.

I am able to turn my computer on and off from my work using:

I understand what the OP is trying to accomplish but, not worth the penny, no PUN
ShawnHymel (author)  bprins2 years ago
It's definitely an expensive way to turn on a computer, I won't deny that :)

I've tried both Wake-On-LAN (WOL) as well as Wake on Wireless LAN (WoWLAN). WOL works beautifully, but only with an Ethernet connection. If your desktop is close to your router or you don't mind stringing cables across rooms, WOL is definitely the way to go.

However, I wanted to go wireless as much as possible. WoWLAN works with SOME hardware (specific WiFi NICs and motherboards) - not mine, unfortunately. I was left with a few options:
1) Buy a new NIC and possibly mobo
2) Setup my WRT54G as a bridge with custom firmware
3) Try something new with embedded systems

I really didn't like option #1. I've done #2 (if you have a WiFi bridge sitting around, I recommend that). #3 sounded like more fun...so that's what I did :)
Metahominid2 years ago
This is quite elegant, I had almost the same situation but was sending Matlab scripts to a professors more powerful desktop and remotely connecting. Since the university footed the bill I figure he wouldn't have cared but it is cool nonetheless
myredhotcar2 years ago
Some PCs will shutdown properly if you just press the off button briefly. My old one used to. Not sure if this is something bios or motherboard dependant.

ShawnHymel (author)  myredhotcar2 years ago
For Windows (and I imagine for Linux and Mac), you can configure the behavior of briefly pressing the power button. Generally, I have mine pop up and ask me what I want to do (e.g. Shut Down, Reboot).

In college, I learned the hard way of having the power button configured to automatically shut down. A nice prank is to walk by someone's computer and hit that button quickly :)
LesB2 years ago
Nice project. I'd like to implement this with a timer so that I can set it for the system to come up at a prescribed time to record TV shows.

Q. How do you get past the Windows log-in with remote startup?

One suggestion: Electrical wiring is more lucidly explained with a schematic drawing. (At least for an old technician like me). ExpressSCH is a nice freeware schematic drawing program with an easy learning curve, and it lets you export the schematic as a bitmap file.
ShawnHymel (author)  LesB2 years ago
If I recall, you can Remote Desktop in to a computer that isn't logged in. You'll be presented with the log in screen, so you can just log in from there. Another way to explain this: the Remote Desktop Server service starts running before you log in.

If you're not going to use Remote Desktop, I see a couple ways around this. 1) Do the bad thing and setup an account with no password - you can have Windows automatically log in to that account. 2) Setup your TV recording programs as services with System-level privileges. I'm not sure which program you're planning to use, but System-level things can run without logging in.

Step 3 has a schematic attached as one of the pictures. I find it helps me, too. :)
ggarnier2 years ago
Was "inscrutable" an autocorrect gremlin, or a self-deprecating bit of tongue in cheek?
ShawnHymel (author)  ggarnier2 years ago
LOL...definitely an attack of the autocorrect. Thanks for catching that :)
clintdb2 years ago
Maybe set Chrome to start automatically on startup, then you can use Chrome Remote Desktop and not only verify that the computer is on, but also access it remotely from any other Chrome browser?
Great Instructable BTW.
Chrome has a remote?
Cool! Have to try that! :)

Thanks alot!
ShawnHymel (author)  clintdb2 years ago
Not a bad idea. My big issue was booting the computer. After that, I could use VNC, Windows' Remote Desktop, SSH, etc. I didn't realize Chrome had a remote desktop, so I might have to check that out.
Orngrimm2 years ago
I successfully made a small server i can wake up on wireless.
BUT: I had to use quite special hardware where you have an always-on-WiFi-Card with a small headercable connecting to the WoL-Pins on the Motherboard...
It was a nightmare to find and build.

So yeah: The solution (Nice 'ible by the way! Like it!) presented here is 100x simpler and for SURE more fun to build. :)
ShawnHymel (author)  Orngrimm2 years ago
I'm glad you liked it! I thought about doing something like you described with a Raspberry Pi, but it seemed overly complicated. I'm curious, are you able to get information about the state of the computer (e.g. ON or OFF) from the WoL pins? That's the one thing impBoot is missing, and I'd like to be able to determine if the computer is on or not.
As you are already taping into the power switch header, why not monitor the power LED header? Hard power off is a really bad idea.
ShawnHymel (author)  -A-N-D-Y-2 years ago
Monitoring the power LED is a good idea as well as the USB ports, as Orngrimm points out. I find hard power off to be handy if Windows (or Linux, sometimes) has issues shutting down. I just don't hit the "OFF" button unless I really have to :)

If you find yourself needing to implement remote boot, and you don't want hard power off, I would just leave out that section out of the Imp code.
As i posted, the hardware i used isnt selfmade... I dont know if you somehow can communicate with the Mobo and ask about status...

But if i were you, i would simply check an unused USB-Port for +5V.
If the Comp is shut down, that should be 0V. ;)
espdp2 Orngrimm2 years ago
And that is a fine example of K.I.S.S. genius!
tlalexander2 years ago
So glad you've gotten use out of my Electric Imp Toggle app! :)
ShawnHymel (author)  tlalexander2 years ago
It was exactly what I was looking for! Thank you :)