geekhack Community => Input Devices => Topic started by: yzdnegel on Wed, 30 June 2021, 16:29:01

Title: Need help identifying pinout for trackpoint
Post by: yzdnegel on Wed, 30 June 2021, 16:29:01
I've been searching for anyone that have the same trackpoint as me and have identified the pinouts. I've seen some people with similar chips (PTPM754DR but rest of the numbers are different tho) but I'm not sure the same pinouts apply to my trackpoint being that they have a different layout. So... defeated I come here for assistance. Has anyone used my trackpoint before or know if pinouts from other similar trackpoints apply to mine?

Thanks in advance!
Title: Re: Need help identifying pinout for trackpoint
Post by: Leslieann on Thu, 01 July 2021, 06:16:17
Many of these are just a USB 2.0 connection (5 or 6 wires with shield, 4 without) and tend to follow USB wiring standards, the two innermost are signal on either side of them is red and black and outside those will be shielding (a normal wire would only have one but being a flat wire it has two).

Odds are it will not fry if you do it wrong so long as you avoid the signal wires and don't leave it plugged in long but it should be somewhat easy to verify what is what with a simple visual inspection. Ground is easy to spot because it will spread all over the board and fill in blank areas while positive will go straight to a resistor and they should be on opposite sides of the cable.Once you have those two, there will probably be two wires in between, try them one way, if the system says it can't find the driver flip them. The two outermost wires may be a shield and or duds. I'd still use a cheap hub just in case it's wrong so as not to damage the computer (unlikely, but still) if you get it wrong.