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geekhack Projects => Making Stuff Together! => Topic started by: kbder on Sat, 08 December 2018, 02:56:00

Title: Integrating Apple trackpad into custom keyboard?
Post by: kbder on Sat, 08 December 2018, 02:56:00

I've been thinking about designing a keyboard which has a built-in trackpad, and it turns out you can buy a replacement Apple trackpad module for about $30!  https://www.ebay.com/itm/Trackpad-Touchpad-for-Apple-MacBook-Pro-13-A1278-2009-2010-2011-2012-MB990/323026073821?hash=item4b35dab8dd:rk:24:pf:0

Question is, has anyone looked into how to connect to one of these things?  connector pinout, protocol, etc.

Title: Re: Integrating Apple trackpad into custom keyboard?
Post by: xack on Tue, 11 December 2018, 01:52:38

I think there you have a lot to reverse engineer, since apple as we all know likes to think different  ;)
How ever I think i would have a look at something like https://www.hackster.io/BuildItDR/arduino-controlled-usb-trackpad-f443a6 and go from there.
Its not an apple track pad but I think it helps to understand how they work and interface in general before going ahead.
What you wouldn't find here (I think) is someone saying "just buy that plug and you are done". It might involve blood, sweat and tears ;)

Title: Re: Integrating Apple trackpad into custom keyboard?
Post by: hanya on Tue, 11 December 2018, 09:01:32

Apple's touch pad uses custom IC to read electrostatic capacitance from the pad. I could not find datasheet for the IC.
Linux uses synaptics driver on Mac PC.
I forgot well about the IC but it might be Broadcom BCM5974 which reads electrostatic capacitance. If so, you can find some driver code in the Linux kernel.

Some people successfully converted old 4pin touch pad into USB touchpad. But recent one has 22 pins. It seems the USB controller is placed on the mainboard for recent version.