geekhack
geekhack Community => Input Devices => Topic started by: Whipplash on Sat, 23 October 2021, 12:21:15
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Hey all! First time around here, but I'd been in search of some help. For some context, I'd been in the midst of attempting to connect a salvaged R61's Trackpoint to my new Corne Keyboard. Long story short..... I spilled excess solder over some of the smaller components of the trackpoint module, and had ended up deeming it un-repairable (with the current of tools that I have of course). In an attempt to keep the project going without having to wait on more parts to arrive, I turned to my Lenovo T570's keyboard. I'd been expecting to maybe find the Two-Piece Trackpoint mentioned here: https://deskthority.net/wiki/TrackPoint_Hardware#2-piece_Trackpoint
However, it seems I found something new perhaps? Would anyone happen to be able to know either the pinout, or how I could go about determining the pinout here? Sorry if it's a dumb question, I'm not the best with tracing small electronics but I'm trying to learn more ;D The thought I had here had been that if I were to grab the schematic for the PTPM754DR I might be able to trace out the RST pin, and somehow find GND, VCC, and DATA in the process, although I'm not certain if that's even remotely correct.
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Replying to my own thread, but I think I've figured most of it out! After doing a bit more internet rummaging, I managed to stumble upon this page for the IC:
https://ajax--chen-blogspot-com.translate.goog/2019/05/collection-of-pinouts-of-trackpoint.html?_x_tr_sch=http&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=nui
Which contained an image of the pinout!
Using a multimeter to trace everything out, I believe the backside pins are as follows:
1 - VCC
2 - DATA
3 - ?
4 - BTN
5 - ?
6 - BTN
7 - GND
8 - CLK
If at all possible, would anyone be able to give me confirmation that traces are correct? Thanks!
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I've had a look but that sticker covering the same area as the main chip really doesn't help.
[attachimg=1]
1 and 7 are thicker traces so they look like VCC and GND and as long as you get those two in the right place you shouldn't be able to kill it, it just wont work.