Interface arduino with Power and Reset buttons

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi there,
I would like to use arduino 2009+ethernet shield in order to power up my PC remotely and eventually reset it in case it locks.

I am not expert of eletronics, so I was wandering if I can:

  • connect my arduino 2009+ethernet shild on an PC USB connector (I can leave it powered on through a setting on the motherboard)
  • connect one digital output in parallel with the PC power button
  • connect another digital output in parallel with the PC reset button

or it is better to decouple ? how?

Bye
Francesco

2

You can generally use Wake-on-LAN (WoL) to boot a system remotely. Check your BIOS for such a feature, and google "wake on LAN magic packet". Yo have to send the magic packet from a system on the same LAN as the machine in question.

More advanced systems have a system known as IPMI where this sort of thing can be done across the network.

If implementing this with an arduino, I personally would power it separately for maximum effectiveness/reliability. Also be aware of the security implications of putting your computer's power and reset buttons on the internet.

-j

3

Hi
I am using WOL now, but if you have programs that use udp punching hole tenciques (e.g. Skype and p2p vpns) you get you PC woke up after you send the sleep command.
(The magic packet does not work on my mainboard)

Anyway I would like to have a way to recover from an error (this is the reason of connecting to the reset putton).

Bye
Francesco

4

I would like to have a way to recover from an error (this is the reason of connecting to the reset putton).

I understand, we have similar issues here at work. The solution we're starting to explore for one particular lab is to use virtual machines, so that the host OS is still functional and can reset the VM for us.

I have considered just the solution you describe, though, for an older server that is quite functional but lacks IMPI for power management, and has an annoying BIOS feature-lack where I cannot enable WoL (hardware supports it but the BIOS doesn't give me a way to enable it).

Anyway, yes what you describe should work just fine. There's probably a couple of convenient headers with the power and reset buttons attached, so you can tap the circuit there with your Arduino. These buttons typically short a line to ground, so you'll want to leave the arduino pin as an input (with no pullup!), then make it an output with a low value to simulate the button press. Go back to input state to release the button.

Again, I would probably power the Arduino separately from the computer just for more simplicity and reliability, but that's just me. If your power supply/mobo will support powering a USB peripheral even with the system "off", that may work just fine.

-j

5

Hi I used the simple messaging system library to pilot the pin 13; I then connected the arduino 2009 pin 13 to the power pin on the motherboard.

Issuing the command
w d 13 1
I can activate the led but I do not see the PC to power up.

any other hints?

Bye
Francesco

6

you could connect the power and reset buttons with an opto coupler, like an 4N28. It's easy and save.

Connect pin 1 to arduino digital out and pin 2 to ground. If you set pin 1 to high, pin 3 and 4 were closed.

the good thing on using your own (external) control, you could hold the power button closed 3 seconds to shut down the pc immediately.

ciao sunny

7

I'm pretty sure you'd need to connect both pins on the power switch to the Arduino. You haven't mentioned that you're doing exactly but it sounds like you're just connecting pin 13 to something on the motherboard.

Anyway, I'd be using a small relay to close the contacts if I were you...

8

I bought some of these:
http://www.clare.com/home/pdfs.nsf/www/Lcc110.pdf/$file/Lcc110.pdf

Can I connect the inputs directly to arduino or do I need a resistor?
And what about the outputs?