geekhack
geekhack Projects => Making Stuff Together! => Topic started by: Melvang on Mon, 04 March 2013, 17:59:29
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Would anyone know if you can run a power and reset switch using a common ground without them interferring with each other? The reason I ask is I want to put them on my keyboard and send the signals via stereo plug and socket but to my knowledge they use a common ground. Any info would be great.
Melvang
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Each has it's own 2 pins on the motherboard, so I would think not.
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I only have 1 mobo outside of a case and handy... both power and reset ground pins are connected to 1 ground. Continuity test goes... beeeeep
That's a Gigabyte EP43-DS3L
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Melvang, I would imagine they use a common ground (alaric's test is further evidence). As far as I can tell, there's no reason not to. Keep a few things in mind, though.
1. If you use any sort of TRS connector for this, both the tip and the sleeve will be shorted to ground when you insert or remove it. So, if you trip over the wire, unplug it, etc. it'll activate power and reset switches. Normally just tapping the power button triggers an ACPI event when the computer is on (usually brings up a menu asking if you want to power down) but this may not be ideal behaviour. I recommend a different connector for this.
Otherwise, you should be able to do this with relative ease.
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So I have more time to post.... As shown by my test they do have a common ground.
The effort it would take to give a separate ground to those 2 switches would be a ridiculous undertaking for no return so take it as a near guarantee that they will be common ground.
But here's the FUN part... You really really really need to make sure you are connecting to the correct pins. That mobo I tested has the pin pairs in reverse to each other. Power is +/- and reset is -/+ but what makes that all the more entertaining is that the 2 ground are NOT adjacent. They are diagonally opposite each other as are the + pins. That may seem silly but it's not really. You can take the 2 cables and plug them either horizontally or vertically and they will both work correctly.
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Thanks for the help guys. As far as inserting and removing the plug triggering an event or tripping over the cord, I don't think that will be an issue. Reason being that I don't move around with my keyboard and I work Union construction so no need for me to take it to work and the cord will be routed back behind my desk. But thanx for all the help with this guys.
Melvang