So I have a trackpad I'm trying to interface with my Arduino. It has a Synaptics T1004 IC and I've seen people getting these working elsewhere on the internet, so I figured this would be quite straightforward, clearly I was wrong! I'm not sure what the problem is; I've cut a chunk of the donor laptop's motherboard off to get the trackpad connector solderable, soldered it all up, checked for continuity where there shouldn't be and there is none. So far, there's nothing to suggest it shouldn't work.
I've wired it all up to my Uno (also tried on a Leonardo), loaded up the PS/2 library's Mouse example and I get nothing on the serial monitor. I've tested it with other sketches and they work fine, just this gives absolutely no response.
Looking at the trackpad, the only thing that strikes me as odd is the SOT23-3 IC that's soldered about halfway along the trackpad's FPCB connector. It has the code '12E' printed on it so I looked it up and it's supposed to be a ZC2812E, "dual series RF schottky15V 20mA", but that doesn't tally with what my multimeter is telling me, which is that it has a common anode connected to the trackpad's GND line and there are two cathodes which go up to the motherboard connector and stop there. One cathode reads 600mV and the other 550mV. Quite why the anode is on the GND line I have no idea.
A rough drawing:
I'm totally stumped. I've tried swapping the CLK and DATA over when connected to the Uno but I still get no signal... Maybe it's dead? The test points on the trackpad seem to be ok, though, they sit at about 4.4V and when you touch the trackpad and move your finger that goes up to 4.55V until you take your finger off. Obviously I have no idea whether it's supposed to do that or not, but it's better than not responding at all. Maybe. I don't know. I'm just grasping at straws because I'd really like to be able to use this trackpad.
Oh actually it may be worth noting that I had to use uber-thin headphone wire to solder this thing up, but it's only a short piece (about 5-10cm). Maybe it's too resistive to give a good signal? I'll check it with my meter and report back ASAP. --- Edit: Checked both CLK and DATA, roughly one whole ohm. Probably not the issue.
Any ideas please?