(This post is very long and has lots of pictures. If you're here to help, but don't want the whole storytime thing feel free to skip to the summary at the end.)
So here's the thing, I'm basically a total amateur. I only started soldering earlier this year, and I still understand very little about electronics and how they work. But that's never stopped me from doing stupid things before.
Right now, the stupid thing I'm doing is trying to make a Retron 5 controller into something that doesn't suck. I love my Retron 5, but its wireless bluetooth controller is awful. It's clicky, it's got this weird pseudo-analog stick style d-pad, it feels light and cheap, and it's just all around uncomfortable to hold. I've got an 8bitdo SFC30 as my go-to Retron wireless controller, but I have to do a weird button combo to get into the menu and not all of the buttons are represented on the controller, and I just want something easier.
Initially my first plan was to hotwire the inputs from a different controller to the PCB on the Retron controller. So the first step was to take apart the Retron controller to see what I was working with, and that's when I was met with my first lucky break.
Half of the work has already been sorta done for me here, with the directional inputs as well as L1 and L2 already set up to be wired to another PCB. All I really have to do is figure out what to do for the other buttons and I'm set, right? Well, maybe not.
I needed to find a controller that would fit the PCB inside, or at least would be easy to mod so that it could fit inside. For a while I was looking to the Xbox 360 controller, which has lots of room, but I decided that the subpar d-pad wasn't worth it. For a while I was actually considering the Xbox One controller, but every broken xbone controller I've been able to get my hands on so far has been either easily fixable or there's nothing wrong with them in the first place, and they're too nice for PC gaming to take apart (and besides they have a really weird thing going where one of the face buttons is actually connected to the first PCB and it was a little too complicated for me). That's when I turned to the Dualshock 3 and stumbled across my second lucky break.
The DS3 has a great d-pad, four buttons as well as two sets of shoulder and trigger buttons, and it's set up so that I can easily attach a bunch of ribbon cable to pretty much everything except the analog sticks and L3/R3 (just don't mind the shoddy soldering job). Not only that, but if I take the second DS3 PCB out, everything on the input PCB but the middle area are fully supported and don't need any backing to keep it steady. Unfortunately, I don't have everything going for me, as the space inside the DS3 controller is still pretty cramped, and I don't think I could fit the Retron controller PCB as is. So, I'm pretty sure I'm going to try to cut the PCB up and remove what I don't really need.
Now, this is a bit of a tall order for me, as I have no idea what almost all of these little metal components on the Retron PCB are supposed to do, and I couldn't find a schematic of the board online, but I think I've got a way to make it quite a bit smaller. I couldn't find a schematic for this piece of hot garbage online (not that I know much about reading schematics anyway), so I had to improvise.
I pulled some of the pictures I took into photoshop and started mapping out what connects to what, with particular emphasis on the inputs. The red lines are paths I found on the front, and the blue lines are paths that I found on the back. The small green dots are the holes where I'm pretty sure the paths are passing through to one side or the other. The purple circles are surface leads, mostly located on the back. I've highlighted where I believe the paths from the button inputs come from in yellow, and right now my initial plan is to cut the PCB where those yellow lines end, up and down the board. As for the bluetooth antenna, I'll either cut around it or remove it and connect it to the PCB again with a wire. In theory this should slim up the PCB quite a bit, but not enough to be able to fit in the DS3 (especially if I want the USB cable to be in the right place) so I'm still a bit stuck there, and I may have to make a bit of a modification to the controller. I feel like I might be able to cut off the bit with the indicator lights and rewire them so that they're near the USB port like they are on the controller, but I'm getting too far ahead of myself, because while testing out the DS3's PCB I came across a potential problem.
I have a cheap, dinky continuity tester that I've been using to poke around and see what connects to what, and up until this point I've been able to get a good idea of which lead sends signals and which do not. I've tested a bunch of the surface leads to make sure I knew where the ground was, I've tested the buttons to make sure I know which prong sends the signal when it's pressed, but when I tried to test the DS3's inputs to make sure that pressing buttons actually sends a signal to the wires, I get nothing. On the shoulders and triggers, there's a very basic circuit, one path splits off and connects to the pads that the other two leads connect to, and pressing down the little rubber contact pad onto it gives me nothing for any of these buttons, left or right, even after extensive cleaning.
So to sum up, I'm trying to take a Retron 5 controller and connect it to the button pad PCBs from a Dualshock 3. I'm planning on cutting up the Retron PCB around where the yellow lines on the above diagram end, but unfortunately I've been testing the DS3 PCB and pressing buttons doesn't connect a circuit between either the ground or the "ADCC" or "ADCD" lines (no idea what those mean, and google doesn't reveal anything, but I suspect it has something to do with power) and what I'm wondering now is if the button inputs work differently between these two PCBs (in which case, this project may be screwed unless I can figure out a workaround), or if maybe every button in this DS3 PCB is broken (I doubt it, but it's possible). I've checked the continuity between the solder joints and the wires and everything. It doesn't make sense to me.
There are some other concerns I have, including the fact that there's a symbol on the Retron board that looks like the symbol underneath one of the capacitors (a circle with a bunch of lines on one side) and I'm wondering if there's supposed to be a capacitor there. I'm also wondering if I need to make sure that the blue line running along the diagonal line on the side of it needs to be connected to something (I'm guessing it's supposed to have power coming through it, so I might be able to connect it to where the power's supposed to go on the DS3, either "ADCC" or "ADCD").
Here's a link to all the pictures I've taken so far in case there's some info I'm missing. Even if you don't feel like offering advice, I'm sure I'll figure things out myself in time. If I end up screwing up and breaking everything here, I'll at least have learned something (I hope). If you have any suggestions for me, though it would really help. Thank you!