Macbook pro trackpad conversion

Posted on by bounav

A few month back my friend Zaf replaced the top case of his macbook pro and had the kindness to donate the old part to me. The reason he changed it was the trackpad wasn’t clicking anymore.

This was the perfect opportunity for me to try converting the top case into an external multi-touch trackpad!

Up to February 2005, Apple laptops’ keyboard and trackpad where still using ADB. Since the top case I had in my hand was coming from a Macbook pro,  I presumed the is trackpad would be connected to the main board using an USB bus. The challenge was to guess the pin out of USB connection on the trackpad and, given the size of the connections on the board, manage to solder the 4 wires required for USB connections on the board.

Looking at the flex cable connecting the top case of the macbook pro to its motherboard, it didn’t took me long to guess the trackpad board was a controller for both the trackpad and the keyboard. Having a closer look I first got discouraged by the smallness of the flex connector and thought I would never be able to connect any wire to the board…

Macbook pro’s trackpad USB pinout
USB experimentation on the Macbook pro’s trackpad
Macbook pro trackpad USB mod

Back to the problem a few weeks later, I realised there were testing points on the board that are used on the production chains to make sure manufactured boards are functional. These test points would allow me to solder the wires of my USB cable!

On the right side are four pictures showing the pin-out for the USB connections on the board and how I soldered small wires to the test points and tested the board. As you can see I melted the some of the plastic connector whilst soldering. It is so tiny it’s really easy to do some real damage.

Once I got the trackpad working I cut the top-case in order to isolate the trackpad and have it nice and compact, standing next to my keyboard. The trackpad works a treat (apart from the button that doesn’t click but it was this way to start with) and it’s great to be able to use the two-finger scroll and tap functions!

The text step would be to make a nice housing for it because at the moment it’s impossible to have the trackpad sat still on the desk, not to mention the back of it isn’t protected, which isn’t very reassuring.

Macbook pro trackpad cut out
Macbook pro trackpad cut out
Macbook pro trackpad made external next to my vintage mighty mouse
Macbook pro trackpad made external next to my vintage mighty mouse
USB Prober Screenshot
Screenshot of USB Prober showing the “internal” trackpad as connected.

Published by bounav

46 thoughts on “Macbook pro trackpad conversion”

  1. Great effort of yours converting a useless piece in to the right use. Its really amazing work required lots of knowledge, passion and determination. Well done! J@yde

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  4. Hey, Im sure you know this form this project, but what are the pin outs of the cable. Im modding a macbook into a desktop and Im just using the small ribbon wire. Any idea of the pinouts?

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  5. Hi Nick, thanks for stopping by. Sorry I don’t know the pin out on the flex cable. If you have a multimeter with ‘continuity test’ mode (the one that beeps when you short the two probes), you should be able to work it out quite easily. Good luck because the flex cable is really really small.
    Hope this helps!

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  6. I love it. I’m going to follow your lead as I can pick up a top case for $30 on eBay. What did you use to cut the case?

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  7. I’m trying to do the same thing you did with a newer Unibody
    Macbook trackpad. I’m wondering how you identified the correct test points to use? On the newer trackpad, everything is just labeled TP1, TP2, TP3, etc with about 17 test points on the board/ribbon cable.

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    1. Hi Ben,
      Sorry to hear that they gave obscure label names on the newer revisions! Never the less your should be able to identify the test points following these ‘hints’:

      The ground point will be directly connected to the ‘ground’ path of the board (the continuous/large path that is spread all over the board).
      The +5V point should be coming off a ‘thicker path’.
      The data + and data – wires will be very likely to be next to each other on the flex, you can track them from there, or try to locate the USB controller chip and find its datasheet and workout the D+ and D- circuit from the chip itself.

      Hope this helps!

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    1. Hi Ray, I believe the trackpad I moded comes from second generation (core 2 duo) macbook pro, which is pre-unibody.
      With regards to macbook (AKA not pro), I’m would guess their trackpads are very similar if not the same as the pro ones…
      Bn

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  9. @ben (unibody touchpad)

    I stumbled across this entry, and thought I’d share what I’ve learned regarding the glass touchpad on the unibody macbooks…

    In short, it’s not possible with just the touchpad, as the mouse USB controller is on the logic board, and not located on the touchpad’s PCB, like the older pads.

    see here: http://www.ifixit.com/Teardown/MacBook-Unibody-Model-A1278/589/3

    There are only 3 ICs on the touchpad’s ribbon cable:

    Texas Instruments: CD3238
    (google => RS232)

    Broadcom: BCM5974
    (google => touch controller)

    SST: 25VF020
    (exact match from SST, 2Mbit flash chip)

    I managed to get a hold of someone at Apple who answered my questions and confirmed this as well.

    Technically you could pull it off, but do need the logic board as well, making it a ~$500-$600 project, instead of ~$50 one. And you’d have to figure out what to do with the logic board, which isn’t particularly small…

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  10. Thanks a bunch for the detail. I had hoped that the broadcom chip also did USB communication, but I couldn’t find any real detail on the chip.

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  11. Hey, any possible way you would be able to figure it out with a slightly newer pre aluminum mb pro? The boards seem similar, but i definitely dont see test points or anything.

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  15. I am working on getting a polycarbonate macbook top case to pinout to USB. I see on youtube someone has done it. I am testing the pinouts on the board and attempting to find the correct connections. Has anyone had any luck? Mine looks like Chris’s:
    http://yfrog.com/1ximg7065bj
    http://yfrog.com/jnimg7066yj

    From the small ribbon if you look at it I am going to say now before soldering that the pinout is similar to bounav’s. Left to right: GND, D-, D+, 5v. (the first 4 pins)

    I have tested the factory test points. The three that are closest to the terminal in a line should be D-, D+, and 5v. The GND seems to go off to C2 and C3 near the square chip.

    That’s all I have so far.

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  17. I have soldered to the points I mentioned, and it WORKS! Fantastic repurposing for these devices!

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  19. And actually i was planning to connect the flex connector to USB but i am afraid of burning the chip by accident. Could i possibly test with a multimeter? What should I look for in the multimeter?

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    1. The only thing you can really check with a multimeter as far as I know is if what you think is the ground test point really is (because it will should be connected to the ‘shield’ path (all the really thick tracks)).

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  20. i got a macbook late 2007 top case (with the same controller board as jeff and dogan)
    do anyone did find the connector pinout?

    jeff can you put your image back plz?

    dogan, did you actually make it work connecting the flex connector? if so, can you give some information about your connection?

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  21. I think it’s easier to de-solder the connector on the ribbon cable and use some wire-wrapping wire to connect to the points. Also, this will work on any model MacBook of that case design. I used to be an apple repair tech and we would regularly switch out models of top case — the design of the trackpad might change but the cable remains the same.

    http://lostsolutions.net/tcpinout.png — here’s a quick picture i made in numbers, of all things…heh. I’ve tested this out and it works like a champ… definitely easier to solder onto and cheaper to replace if you mess up. 🙂

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  22. oops, forgot to mention, i’m using a macbook top case, not a macbook pro one… same rules apply, in fact you can actually use a macbook cable to plug into the macbook pro trackpad (they are the same). The macbook pro cable just includes some extras like bluetooth and some sensors.

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  23. thank you so much,
    i’ll try it.
    one last question, if you were a apple repair tech, do you think i can wash my topcase in hot water and let it dry for a week? will it work after that?
    thx

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    1. Do you think i can wash my topcase in hot water and let it dry for a week?

      I’d use a piece of cloth lightly soaked with isopropyl alcohol to clean the top of the case: It’s going to dry very quickly and should clean it very well (alcohol is great to remove grease!)

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  25. thx for the respond, but it don’t think alcohol will be enough,
    i got candle wax on and under some key of my keyboard…
    thats why i want to use some hot water.

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  26. In that case i’d try to gently scratch the wax. Water would damage the keypad if you spill some on it. Ultimately, the keypad is held against the top case using super sticky double sided tape. You could propably unstick it and perform a very deep clean of the top case but you might not be able to stick it back…

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  27. @bobledob: Definitely don’t use water… the problem is that it won’t be able to dry easily with all the layers in the keyboard, and there’s no easy way to take it apart.

    @McKean: You might be in for an uphill battle with the unibody case conversion. The problem with that is the keyboard plugs directly into the motherboard and doesn’t use the trackpad for USB conversion like the older ones do. I remember the cable looked pretty similar, so maybe you could use a trackpad from one of the older MacBooks to hook up to the keyboard, but that’s a really big stretch… chances are the keymappings wouldn’t be right. You *might* be able to use the trackpad, but I kind of doubt it’s straightforward USB, there are over a dozen pins on the connector it uses, plus, there’s some hardware in the cable itself if memory serves, not sure what it’s purpose is.

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  28. I tried soldering to the factory test points but it’s just too micro for my eyes and for my hands that I’ve been cracking for year with pleasure 🙂

    I liked tony’s idea though, and thanks a lot for the picture tony…

    It’s still very very micro again though 🙂

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  29. You guys have any idea how you would solder something so small? Is there another way that I still cannot see? 🙂 yeah the desolder ribbon connector is good for knowing the points to solder to but the fact that those points are way too small for the solder I got from homedepot still throws me off. 🙂

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  30. who i was searching the internet for a usb touchpad simular to apple . and only found the wacom bamboo touch but after reading reviews i find out its not as good as the mac book touch pad . so i checked system profiler and saw that the touch pad was connected to usb controller. then google brought me to this page.

    this is great am now going source a touchpad and and case that i can fit it in.

    ill report later

    on thing any one knows if the all in one touch( that doesn’t has the button at bottom ) pad thats in the macbook pro is the same pin out.

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  31. Would any one be able to provide some help for the same mod on a 17″ 2.5GHz model multi touch trackpad. If the test points are too difficult, would it be possible for someone to show me what the pinouts are for the ribbon cable that plugs into the trackpad board? I think only four of the 8 pin cable are actually wired to the trackpad board. I can go from there and test which test point each channel on the ribbon cable leads to.

    Cheers!

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  32. hi,
    i just solder a usb cable to a macbook topcase cable, they are really small, but look good.
    i try it on my mac and nothing, the keyboard and trackpad don’t work.
    i try on a PC, the PC recognize it as an apple keyboard trackpad, but it don’t work (i think it’s a driver probleme)
    because the pc recognize it, i think my solder are good, but why don’t it work on my mac?

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  33. Hi,
    thanks for this tip! I successfully done it using a macbook 13′ topcase. It’s work both on mac and pc with no aditionnal driver. The pcb wiring is a little bit different but thanks to tony cable pinout I managed to find testing points.
    I want to use it on my macbook who have a broken topcase connector (it just recognizes the power button, and I tried several topcase with no luck). Does anyone can help me to find an internal usb on the logical board?

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  36. Thank you Bounav and tony for your insight.
    Do you know if the macbook air’s touchpad has the usb controler on it like the preunibody macbooks?

    I would like to mod my laptop to get multitouch. I first looked at the wacom bamboo but it’s too big. The touchpad of a macbook might just be perfect for my hackintosh and I like the idea of patching my pc with a mac 🙂 .

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