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A monthago I posted an instructable over recycling a Laptop webcam (https://www.instructables.com/id/Laptoprecycling-Webcam/), three weeks ago I posted a second instructable over reusing the Bluetooth module of the Laptop (https://www.instructables.com/id/Laptoprecycling-Bluetooth/)now I’m back with the third instructable over recycling the parts of a broken laptop. This time I choose the Touchpad.

Materials:

A Synaptics Touchpad or TrackPoint

A PS2 plug with cable from mouse or keyboard or a RS232 plug

Some wire

Superglue

Solder

Optional: PS2/USB Converter

Optional: Two or more buttons if they are not on the PCB.

Optional: A mouse pad with a plastic surface (mine was a cheap advisement present)

Optional: Something to large up the button heads like ICs

Optional: a wooden plate

Tools:

Soldering iron

Pliers

An exactor knife

Some rubbing alcohol

Optional: a hairdryer

Optional: A drill

Optional: a pen

Step 1: Get a Touchpad

The first step if you are working with CMOS is to ground yourself, specifically if you have a carpet floor like I do. I use an antistatic wristband, but if you haven’t one you can also touch a radiator or a grounded case before you start working. OTHERVISE YOU MAY DEMAGE SOMETHING!!! In my case the touchpad was integrated into the case. It was glued to its back and after heading it with the hairdryer and a bit of bending it around it came of easily. On the PCB there was some glue who can be cleaned away with some rubbing alcohol.

Step 2: Identify Your Touchpad

Synaptics Touchpads do always have their model name at the same schema as it is shown in picture 2.

Product class: Type of sensor. TM for Capacitive touchpads, TS for TrackPoint’s

ASIC type: Shortcut for the processor type

Host protocol: Type of Connection Interface. Now this is very important! There should be written a P, because that means PS/2. This solution only works with PS/2 Touchpad! Other Letters can be B for a PS/2-Serial combination, I’m not Sure if this works too, but I think it should. S means Serial only, You could try to Use T11 like TX and T10 like RX, but I’m not guaranteeing that it will work. A means ADB, what is a transmission protocol invented by apple for their keyboards and mice. If you like to use that you need an apple pc with a ADB interface or you can try This: https://trmm.net/ADB_to_USB or this: https://geekhack.org/index.php?topic=14290.msg277407 T10 would be the ADB Signal, and T6 the Button. The Last possible letter is a T. T means TTL. To use it connect it like a Serial only touchpad, but with a Serial-TTL or TTL-USB Converter IC like the good old MAX232 between Touchpad and PC.

Orientation: Says which side X+, X-, Y+ and Y- is. This can be U for Up, D for Down and P for Portrait.

Color code: Color of the Touchpad PCB.

Auxiliary Feature: Letter for Extra Features like More Buttons, Customized firmware…

Board type: Size and Resolution of the Touchpad. The possible numbers are listed in picture 3

Revision: Optional for Version

Step 3: Test the Touchpad

The touchpad was connected with a 12 pin ribbon cable, but not every touchpad has the same pin out, so I searched for an alternative way to connect the touchpad, and found it: on the back of the PCB there are some solder pads, who are named with a T and then a number. After a little bit of reverse engineering I had the pin out: T22 is 5V (CTS on RS232), T23 is GND (GND on RS232), T10 is Clock (RTS on RS232) and T11 is Data (DTR on RS232). Don’t look at the colors of the wires, they are not normed and the position of the solderpads can be also different on each model. All the other pins aren’t used yet. Now it’s time for the first test, therefore I used a second plug without isolation to see the pin out and soldered it in the correct way to the solder pads on the touchpad. I plugged it over a PS2/USB converter to the pc and checked the function.

Step 4: Buttons

On my notebook the buttons were on the Motherboard and not on the touchpad, so I had to add external buttons. After finding the correct pins by following the conductor patch, I added two buttons between T6 and ground and for the left button T7 and ground for the right button (Sometimes the pin T2 and T6 are flipped around). If you need the “mouse wheel” too you can see the pin out on picture 1, but notice that may not every button works on each touchpad. Reconnect it to your pc and test the buttons.

Step 5: New Wire

My plan is to put the touchpad into a mouse pad, therefore I drill a hole into my table to fit the cable trough. I placed the mouse pad over the hole and marked the hole to the back of the mouse pad. After fitting the new wire thought the hole and verifying the pinout of that wire with my multimeter I soldered it to the touchpad. Now the new buttons: I desoldered the original SMD pushbuttons from the mainboard and ad some wire. Because they only have a small head I decided to make them larger, otherwise you always have to search for the buttons. Therefore I used two ram ICs from a broken graphic card. Add a very small drop of superglue to the button head and stick the IC over it.

Step 6: Housing

Now we are going to modify the mouse pad to fit the touchpad in. Lay the touchpad and the buttons to about the middle on the back of the mouse pad, Double-check that the touchpad is not flipped around and mark the position with a pen, you can also mark the position of the wire. Now start by cutting out the marked rubber and look if under there is a plastic foil or paper. If there is paper you can’t use superglue, because it goes inside the paper and makes it transparent. In my case fortunately there was a plastic surface. Lay the touchpad inside its hole and check if everything fit, otherwise large the cut.

Step 7: Installation

After cleaning the touchpad and the hole with some rubbing alcohol apply some superglue to the touchpad and punch it inside the hole. Don’t safe at the superglue, otherwise the touchpad may don’t work perfectly. If your fingers look like mine in picture 3 and 4 you took enough superglue :-). Repeat it with the buttons (and the wire). Now solder the wires of the buttons to the solder pads if you removed them. It’s nearly finished, Test it, and you can glue it to your table or a wooden plate.

Step 8: Software and Other Variants

The very last step is to get the driver software, you can download it from the manufacture’s website of your laptop or directly from Synaptics (http:www.synaptics.com/en/drivers.php). The driver normally isn’t need, but it gives you a few extra setting possibilities like scrolling and zooming (if it is supported by your touchpad). If you haven’t got a touchpad you can also use a TrackPoint. It has the same pin out like the touchpad. You can also add it to an Arduino or a Raspberry Pi. There’s only one more thing I have to say: it is not very precise, for designing a PCB I prefer to use a normal mouse. But for easy movements, like opening files an surfing it is a great solution, specially if you only have a little space around.

I also added a short video, where you can see that it actually works!

Thanks for reading my third Laptop recycling project, more of it will may come soon!

Gabs'e

<p>Really cool !</p>
<p>Many thanks!</p>
<p>Nice Useful Instructable, Thanks Gabse</p>
Thanks, MahmoudTolba
<p>WOW great work :D</p>
<p>Thanks</p>
<p>Great and great &quot;ible&quot;</p>
<p>Thanks</p>
<p>I believe the proper word here would be SOMETHING, not SMOETHING.<br>Your good friend,<br>Grammar Nazi</p><p>Otherwise, great project. :)</p>
<p>I don't believe that was a grammar error. It was a typo.</p>
<p>Thanks for spotting my issue. Already corrected.</p>
While you're at it, here's another correction:<br>My plan is *to* put the touchpad into a mouse pad<br>
<p>DomnuT, I understood everything he wrote, english is obviously not his first language and that makes this instructable even more commendable, so why worry about it?</p>
sure.. not shure three... not tree
<p>Thanks, corrected</p>
<p>Useful instructable. Could you tell us how did you get the exact pinout for your model? I believe many of us would benefit from that piece of puzzle.</p>
<p class="MsoNormal">Shure. I found <br>the PDF file, where was written, that it is working whit PS/2, so I knew, that two <br>of the solder pads are for DATA and CLOCK. First one was Ground. I saw that the <br>pin 23 was directly connected to the board&rsquo;s ground fill, so this pad has to be <br>GND. Next was +5V. I simply measured the voltage between the GND and each other <br>pad on the working laptop&rsquo;s touchpad you can see in the cover picture. On that <br>laptop there is a small board between the touchpad and the motherboard with the <br>buttons on. By beeping out the connections of the buttons and the touchpad, I found <br>out with pin is for with button, and that they switch to GND. Between motherboard <br>and the small board there is a ribbon cable with only 4 connections. I painted <br>down which of this wire goes to which solderpad, and so I found the two lines, <br>who have to be for the data and clock. They were 10 and 11. I simply soldered the <br>wire you can see in picture 3 and 4 (step 3) to the pads and tried out which pad <br>is DATA and which CLOCK. I do have a second laptop, who has the buttons for <br>scrolling to the sides, so I simply reverse-engeneered the connection between <br>the buttons and the solderpads. And VOILA! <span style=""> I had all the connections.</span></p>
<p>Thank you. Too bad I don't have the laptop from which I salvaged my trackpad... guess I will only have PS/2 trackpad as this is the only thing I can make out of all resources I have. Or if I ma lucky and get official datasheet, I may actually have a chance at making it proper...</p>
<p>There is a newer version of the datasheed too, but it contains only informations about PS/2 protocoll, so i decidet to post only the old version. In the newer version is written &quot;Most TouchPads support the two traditional mouse buttons, Left and Right. Some TouchPads support additional buttons in various configurations, such as:</p><p>&bull; two standard buttons (Left and Right), and up to eight optional extended buttons,</p><p>&bull; three standard buttons (Left, Middle, and Right), and up to eight optional extended buttons, and</p><p>&bull; four buttons with a specific (Up-Down, Right-Left) coding.</p><p>&quot; you can get it here : <a href="http://www.synaptics.com/sites/default/files/511-000275-01_RevB.pdf" rel="nofollow"> http://www.synaptics.com/sites/default/files/511-...</a></p>
<p>Interesting! =D</p>
<p>Thanks</p>
<p>Great work my friend, I love how you integrated it into the mousepad!<br>I have salvaged a few mousepads from broken laptops, but never acually used them.<br>Even though I studied enough to figure the PS/2 connection out, the lack of buttons prevented me from actually building anything. Thanks to your pinout in step 4 that is solved. Thanks ! ! ! </p>
Thanks
<p>Great idea, now if only there was a way to use a laptop with a dead cpu as a second monitor</p>
<p>This one is easy, I did it more than once and you can do more than just a second monitor with a dead cpu laptop.</p><p>Try searching for &quot;laptop lcd screen display DIY&quot; in your favorite web store. In eBay you'll pay 20-50$ depends on model and functionality.</p><p>BTW, I have converted an old PowerBook (Mac) to a mobile multi media player using something like the followings: <a href="http://www.ebay.com/itm/LA-MV29-P-HDMI-USB-AV-VGA-ATV-PC-LCD-LED-Controller-Board-LVDS-DIY-Reuse-Laptop-/371237916583?pt=LH_DefaultDomain_0&hash=item566f810fa7" rel="nofollow">http://www.ebay.com/itm/LA-MV29-P-HDMI-USB-AV-VGA-...</a></p>
<p>https://www.instructables.com/howto/broken+laptop+as+second+monitor/</p><p>A few solutions already there, most require an extra controller + power supply, which usually cost a little too much, considering you can get a second-hand monitor (complete with power supply,cord,stand,signal cable) for less. Compatibility might also be an issue, even with same resolution monitors... </p>
<p>Brilliant! Bloody brilliant -- this'll come in so handy.</p><p>Thank you.</p>
<p>Thanks</p>
<p>Very interesting - I've hung on to two or three old laptops for spares but never realised you could add a USB i/f to the trackpads - and I have Pi that might benefit from this, maybe even my main PC...</p>
<p>exactly what I was thinking. I hate having the mouse attached to the pi/kodi for when someone doesn't have the tablet/apps remote avail...</p>
<p>Thanks</p>
<p>Good work and good DIY</p>
<p>Thanks</p>
<p>AWESOME, I love recycling projects, Can you recycle the LCD monitor from the laptop?</p>
<p><span style="font-size: 11.5pt;font-family: Arial , sans-serif;color: rgb(51,51,51);">You <br>could try this: <a href="https://www.instructables.com/id/LCD-Photolamp/" rel="nofollow">https://www.instructables.com/id/LCD-Photolamp/</a> <br>if your monitore is broken, ore something like this if it is till <br>working: <a href="https://www.instructables.com/id/Turn-a-dead-laptop-into-a-monitor-with-Plexiglas-s/" rel="nofollow">https://www.instructables.com/id/Turn-a-dead-laptop-into-a-monitor-with-Plexiglas-s/</a></span></p>
<p>Thank you, and everyone else who replied. I also have some LCD's from an old printer and some old cell phones too that I would like to reuse.</p>
<p>You can, there are inexpensive controller boards that can be had on ebay.</p>
<p>You can make a projector out of an old laptop screen.. https://www.youtube.com/watch?v=V0bGcmWRHUk</p>
<p>The idea is super cool. The haze on your photos can be sharpened by cleaning your lens with a soft cloth. Even without the cleaning, it gives a &quot;Holy-ness&quot; to the pictures - ha ha! Nice effect. </p>
<p>thanks for your reply. sorry for the bad quality, but my cell phone has a scratched lense</p>
<p>Excellent step by step layout and attention to details. I don't want to <br> start an anti static debate; as they are never ending and subjective. <br>I'm just curious what kind of anti static necklace do you have and is <br>that all you are using? I have wood floors, so unless I'm pulling ram, <br> have a high end piece of scrap, or am packing components I don't use a grounded wrist <br>strap unless it happens to already be on. I have never come across an anti <br>static necklace that is as effective as a grounded wrist or ankle strap; <br> then again I've never looked either. If I had carpet and an ungrounded <br> work area I would be far more careful with all items. </p>
<p>Did i wrote necklace? Ah yes i did. Of course i meant wristband. :-) Already corrected.</p>
I was gonna say... Man if he has a necklace that is grounded, he must look like the gimp in Pulp Fiction when he's working on electronics. Thanks for the detailed write up and link to the PDF it's jam packed with great data.
<p>Love it...If only because i used to design these things (for Synaptics).</p>
<p>Thanks. Oh really you designed them? Sounds cool!</p>
<p>What an amazing idea! I love projects made from broken stuff :)</p>
Thanks

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Bio: I am an 20 years old mechatronics and I&rsquo;m living in the north of Italy. My interests are working on electronics, playing computer and ... More »
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