Computer motherboard power managment via embedded device

Discussion in 'Embedded Systems and Microcontrollers' started by crevia12, Oct 29, 2015.

  1. crevia12

    Thread Starter New Member

    Oct 29, 2015
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    Hallo,
    I want to develop an embeddde device to manage a computers power. To be able to power it off or on and most importantly. I want the device to be attached to the motherboard system so that it cant be detached from the system and incase on tries, there is apower failure and the computer cant start. Am not sure of the computer component to target on the motherboard, so am asking if anyboard can give hand and help me out.
    Thanks
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    What you want ain't exactly clear. A modern computer has several power supplies and for all I know there is already an embedded power management system on the motherboard. Are you planning to implement a redundant system, or one with additional functionality?
     
  3. Brownout

    Well-Known Member

    Jan 10, 2012
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    My take is he wants to be able to restart a computer in case of a power failure. That's a fairly common desire. I guy I used to work with uses a UController to send his server a restart whenever his machine stops sending a 'heartbeat' message. I'm not sure what the restart consists of though. I've though about a similar thing using a relay connected across the front panel switch header connection.
     
  4. MrSoftware

    Active Member

    Oct 29, 2013
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    If I understand, you want your device attached to the motherboard to control system power, and if someone removes it from the motherboard then the computer won't run at all. Is this right?

    Is it enough to be inside the computer case, or do you have to be integrated on the motherboard itself?

    You didn't say what kind of computer, so I'll assume a typical desktop PC. Going from memory... I believe the power button on the computer case connects to the motherboard, and the motherboard signals the operating system when the button is pressed. Short presses allow the operating system to control what happens (typically sleep, hibernate or shut down), long presses instantly remove power from the mother board. Another short press restores power, turning the machine back on. You can insert your device into the wire between the power button and the motherboard, giving you control of that signal. Or if you must be integrated ON the motherboard, then try to follow the traces from where the power button connects to the motherboard and see if there's a convenient place to break the connection and insert your device. Maybe there's a device somewhere along the line that you can replace with your own. I don't know how many layers are on motherboard PCBs, but I suspect it's going to be challenging to get your device onto the motherboard directly. I hope this helps.
     
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  5. JohnInTX

    Moderator

    Jun 26, 2012
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    Not sure either but many (most?) BIOSes provide a setting for what to do after power is restored after a failure. Hit whatever magic key enters the BIOS setup during startup and see what's there.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    does removal of your "device" damage the computer or just require the computer is turned off or lose power while your devices is being removed?
    how do you plan to control this device? its own IP address? bluetooth? Communication through the host computer?
     
  7. crevia12

    Thread Starter New Member

    Oct 29, 2015
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    removal of the device damages the computer in such away that it cant start. the device is going to be controlled via gsm network. Although the device is not exactly attached on the motherboard. i want to be able to connect on the mother via cables that once one of the connective wires are broken. the computer doesnt start
     
  8. crevia12

    Thread Starter New Member

    Oct 29, 2015
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    yes thats right. ts alaptop computer and i plan to make the device sit into the pci port. so its going to be real small. your suggestion is good, but if i hook the device on the power button wire so that its able to make pulses as those made by the button some one could figure it out easily and reconnet the cable jumping the device. i want the device to replace apower componet in the system to create pulses made by that specific componet so that one can not jst replace the device and still the device does the job or sleeping, hibernating or shut down the pc remotely. which componet could this be on the motherboard
     
  9. Papabravo

    Expert

    Feb 24, 2006
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    It might not be a single dedicated device, but part of a larger chipset. These chips have a variety of names but basically provide the command and control functions for peripheral devices on one side and interface to the CPU bus on the other side. I guess we'd need more information on the laptop and the specific chips it has inside in order to be more helpful. There are just too many possibilities.
     
  10. MrSoftware

    Active Member

    Oct 29, 2013
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    As @Papabravo indicated laptops can be very proprietary and tightly integrated, and your solution will likely vary between different model laptops. Maybe you can find a power mosfet, or some other power controlling device that can be physically removed and hook your device in through those contacts, integrating the removed part into your solution? Are you making just one or two, or is this for production?
     
  11. crevia12

    Thread Starter New Member

    Oct 29, 2015
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    Apower mosfet is agood a idea. If its removed and replaced with my device to the same job. Cant somebody realize the jump and soon replace it with the original thus getting rid my device on the board. Am suggesting a digital componet which its data can be analysed and my device is programmed to forward or relay the data through it. i think this could be difficult for regular mechanic to work out. What componet can i target here on the mother board
     
  12. sirch2

    Well-Known Member

    Jan 21, 2013
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    as others have said you are going to be tight on space in a laptop but most computers connect power to the mother board via a cable and connector. It may be possible to remove this connector and replace it with a little circuit board which is epoxied as well as soldered to the motherboard containing some "propriety" power control device with flying leads from there to the thing in the pci port. The PCI device then controls the power and whatever signalling is necessary to switch the "propriety" power control. Any attempt to get the epoxied board off the motherboard will probably destroy the mother board.

    All that said, remember that anything useful is on the hard disk which can be taken out and read on a separate computer so I'm not sure what going to all this trouble achieves. If you just want to stop someone turning it off/on, lock it in a steel box.
     
  13. crevia12

    Thread Starter New Member

    Oct 29, 2015
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    Than
    Thanks alot you guys..i appreacite all that u have shared with me. If bit locker is turned on the harddisk i belive information on that harddisk is secure and cant be used on anyother machine apart from that machine. Am not forgeting that it can be wiped and used on another machine. The point here is that; alaptop equiped with this device can be controlled by the owner anywhere and incase the laptop is stolen the owner still has controll over it via the device. So making it sticking on the motherboard is acrucial point in the design.
     
  14. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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