Mathew!
Posts: 5
Joined: Thu Jun 14, 2012 12:58 pm

Laptop keyboard and other componant reuse, need some advise

Wed Jul 20, 2016 6:26 pm

Hello, not 100% certain how to title this post as it is pretty damn general but I need some advise on a keyboard I have scavenged from a hp compaq 6730b, the device arrived dead, so no luck with using it as it is but me being the type of tinkerer I am came up with a plan to recycle the dead laptop mostly for fun so far I have dismantled the device and identified a way to patch the lcd using a LVDS adapter, the trackpad and buttons are controlled via a usb IC and the same is true of the web cam now the last thing I have became interested in is the keyboard, this keyboard has a 30 pin ribbon connector, my google studies tell me I am dealing with a 30 pin button matrix, So yes one solution would be to rig all 30 pins via a breakout board to a PI's GPIO(I have a first gen version B I can reassign for the task) but this will take up too many of the gpio pins as I would like to use those for atleast SPI and JTAG programming.

So, I googled about finding a 30pin gpio connector for perhaps extending it off the usb and using an eeprom to store a ident for udev to understand, so far this came up with not much that I could find so I decided it would hurt, you guys got any ideas?

Because it'd be really cool to rebuild this laptop into a multi programmer laptop and at this time it feels silly to be blocked by such a simple feeling problem.

klricks
Posts: 6776
Joined: Sat Jan 12, 2013 3:01 am
Location: Grants Pass, OR, USA
Contact: Website

Re: Laptop keyboard and other componant reuse, need some adv

Thu Jul 21, 2016 4:26 am

Although it seems to be a simple task to get a 'raw' keyboard to work, it is not really that simple. IMO possible, but not feasible. You would have to figure out the keyboard matrix, ...... and find a way to physically interface the ribbon..... Write code to interpret key presses via GPIO, ........then somehow get the key-press information to the OS.
I would ditch the keyboard idea and attach a mini USB keyboard of some sort in its place.
Unless specified otherwise my response is based on the latest and fully updated Raspbian Buster w/ Desktop OS.

lumsdot
Posts: 123
Joined: Wed Mar 11, 2015 5:29 pm

Re: Laptop keyboard and other componant reuse, need some adv

Thu Jul 21, 2016 4:28 am

This hackaday project converts a zx spectrum 4 by 10 matrix keyboard into a usb pc keyboard using an arduino

https://hackaday.io/project/2076-zx-keyboard

All you need to do is change the mappings into the arduino code to refelect the fact your matrix is different to a zx spectrum matrix.

Ps ive used this project to make my zx spectrum into a pc keyboard and it does work

Mathew!
Posts: 5
Joined: Thu Jun 14, 2012 12:58 pm

Re: Laptop keyboard and other componant reuse, need some adv

Thu Jul 21, 2016 6:11 pm

lumsdot wrote:This hackaday project converts a zx spectrum 4 by 10 matrix keyboard into a usb pc keyboard using an arduino

https://hackaday.io/project/2076-zx-keyboard

All you need to do is change the mappings into the arduino code to refelect the fact your matrix is different to a zx spectrum matrix.

Ps ive used this project to make my zx spectrum into a pc keyboard and it does work

That tutorial gave me the outline to work with, from what I can work out the arduino is less then 30 pin GPIO my research is making me look into a pic32 solution, as I have had prior experience with the the PIC16 and it appears to have 32 GPIO pins, 2 more then I need but room to work and even include a stand by switch.

I noticed the poster above advised a mini usb keyboard, I do agree that would be the easier way but for this study case I am going in deep.

Return to “General discussion”