When using a driving cockpit for simulators like rFactor, a pointing device is mandatory to interact with the GUI. Not only it is necessary to move from one menu to other, but also to adjust the car and race settings. Some solutions include a custom tray and a mouse, but it requires a lot of space around the seat that is not always available. In my case, I usually have to use the mouse on the keyboard tray with my left hand, and I hardly reach it. 

 

To solve this, I have repurposed an old touchpad from an Acer Aspire 1690. The model of the chip is Synaptics T1006 0544, and it uses a PS/2 serial communication to the computer. As the laptop uses a custom connector, all we have to do is to find the datasheet of the controller and wire it appropriately. 

 touchpad wired to PS2 connector

 

I found the schematic on this blog. The pinout of interest of the chip is:

Pin no. in chip   Description   Pin in PS/2 conn.  
2 Data 1
3 Clock 5
43 Vcc 4
45 Ground 3

Pin number one of the chip is marked with a circle, and following pins are numbered counter-clockwise. The pinout of a regular PS/2 mouse connector can be found here. To solder the wires, I traced the pins and used the testpoints of the board. 

For modern computers, a PS/2 to USB adapter (can be found easily on ebay) is convenient. 

Next thing to do is to make a frame and a support for the cockpit. I have made mine with a thin sheet of metal and wood.