geekhack
geekhack Projects => Making Stuff Together! => Topic started by: chlysm on Mon, 16 January 2017, 09:32:12
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I have some old Dell Laptops laying around and they are obsolete to the point of uselessness, and I thought it would be nice to convert one over to a portable monitor/keyboard/mouse like a rackmount console, but way way cheaper.
I know you can get the LCD to work using an LCD controller board, but what I'm trying to figure out is the best way to handle the keyboard mouse functions.
And no, VNC/RDC and software KVM applications will not work, this will need to be able to view and configure the pre-boot screens.
Basically what I would want is for the laptop keyboard/track pad to be recognized as an ordinary USB keyboard by another computer and as far as I know the only sure way to do this is to make a custom arduino or other DIY board to act as a controller and send the keyboard via USB. However, I wonder if there is a way to send keystrokes over the serial port. That of course would still require another device to relay the keystrokes, but would mean less physical modification and leaving the possibility open to use the working laptop hardware for other things. Furthermore, a device intended for relaying keystrokes over the serial port should work just the same on any laptop or PC that has a serial port.
In the end, I just want something that will function reliably once it is finished. Thanks in advance.
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Just about all laptop keyboards connect to either PS/2 or USB. If they are running you can bring up device manager and see if the computer recognizes either a PS/2 keyboard or a USB one. The internal connector is obviously different but if you can learn if yours are PS/2 or USB, from there the conversion is easy. Or, really, no conversion necessary. You'd just connect four wires (in either case - they're both just four wires) to the proper cable to run out of the case.
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Sorry, I didn't finish. If the keyboard is PS/2 you'd just connect the four wires to a Teensy and with either Soarer's converter or TMK PS/2 to USB converter software running on the Teensy it's now a USB keyboard.
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Most of the laptops that I've taken apart have some sort of ribbon connector that connects directly to the motherboard. I would imagine that I can't just split the wires and splice them in to a PS/2 connector. Are there any teensy or other DIY boards that would be able to connect to the ribbon connector thus making the individual wires accessible for modding?
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Most of the laptops that I've taken apart have some sort of ribbon connector that connects directly to the motherboard. I would imagine that I can't just split the wires and splice them in to a PS/2 connector. Are there any teensy or other DIY boards that would be able to connect to the ribbon connector thus making the individual wires accessible for modding?
We don't know exactly what you'll be dealing with but each conductor in the ribbon cable has to connect to a trace on a PCB. You might be able to grab the signals by soldering to those traces. Or, it is possible to connect wires directly to the cable:
[attach=1]
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Another thing to keep in mind is that the keyboard controller may be on the motherboard and not the keyboard itself - and you have to connect to the controller output. So you may need to trace the cable from the KB to the motherboard and find the controller there. Or the controller may be integrated in a chip which also does a bunch of other stuff, in which case this may not be possible at all. We could guess all day but there's no way to know what you'd be dealing with without opening the computer and taking a look.