Tuesday, November 29, 2011

Synaptics Touchpad on PS/2

In an earlier post I wrote about my attempt to take out a Synaptics Touchpad form a laptop and connect it to my computer's PS/2 plug. 

The Synaptics Touchpad pinout seems to be different for each model, so be careful not to fry the  circuit! Triple check every pin and connection before you power this up. Also remember that the touchpad is not plug and play: you need to connect it to your computer before powering it on.

I have used a Synaptics T1006 0544 touchpad. 
The pinouts for the PS/2 keyboard connector and the Synaptics T1006 0544 touchpad can be viewed in the schematic below.

You can observe in the schematic that I only connected the communication pins (Vcc, Ground, Clock, Data).
The pins Left Click, Right Click, Scroll Left, Scroll Right, Scroll Up, Scroll Down can be linked to external buttons (I haven't done that because the Synaptics software allows default scrolling and normal tapping).
For the right mouse button you can define a corner of the touchpad that when tapped will trigger the right mouse click action.

Good luck!

Sunday, November 6, 2011

Laptop touchpad for my desktop

I like laptop touchpads (almost every laptop I've ever used had a touchpad that behaved well). I also like computer mice as input devices. 
Everyone knows that with a good mouse you can do just about everything - from browsing to multimedia editing - sound, video and even fine graphics. 
What about the touchpad then? They say it's not a very precise input device. I think they're wrong. Back in the days, I was playing Counterstrike using my laptop's touchpad and I was good too.

The cool thing about the touchpad is not having to move your right arm away from the center of the keyboard every time you need to access a different object on the screen. You just need to move your thumb from the Space key to the touchpad (1 cm movement). That's faster and more efficient.

After switching to a desktop computer, I've been searching for years a keyboard with integrated touchpad. Most of the keyboards with touchpads have the touchpad instead of the Numerical Keys (in the right) or under the Arrow Keys. That is not ergonomically correct.

One day, the revolutionary Steve Jobs had an ideea: What if we made the macbook's trackpad a standalone version for the desktop users? This way, Apple's Magic Trackpad was born. The Magic Trackpad has a big working surface and it's wireless. It is tilted to and angle similar to Apple's keyboard. It's designed to be placed in the left side or the right side of the keyboard. You can't place it between you and the keyboard, under the space button, because of that angle. 

Because the Apple Magic Trackpad wasn't helping me, and I couldn't find any good keyboards with touchpads, I decided to dig a little bit  more. 

If you open a laptop and look inside it, you'll find a slim, small touchpad that's linked to the mainboard with a flex cable. And so the big question raises: Can we use a touchpad from a laptop on a desktop? 
Well, the answer is: WE CAN! Laptop touchpads are communicating with the laptop via a PS/2 interface. If you can extract the touchpad from the laptop and properly connect it to the PS/2  interface on your desktop, then, you've got yourself a new Desktop Touchpad.

I managed to take a touchpad from an old Acer Travelmate 2410 and connect it to the desktop. I'm using it as I write this post. I will write a technical tutorial on how I did all the work. Stay tuned!