TL;DR: what gauge of wire and route should I use to light up ABXY?
I have added LEDs to my ABXY buttons (individually switched, see
https://www.acidmods.com/forum/index.php/topic,44629.0.html), but my wiring isn't very reliable and I have had to open up the controller (unsoldering the rumble motors &c.) several times to reconnect wires that have come apart. I used what was advertised as red and black multi-stranded 30 AWG kynar wire, but when it arrived was actually two red wires, but one length of multi-strand and one of single-strand somewhat thinner wire. The single-strand seems to be 0.2 mm in diameter, and the multi-strand 0.2 to 0.4 mm in total, depending on how hard I press the jaws of my micrometer. But as my micrometer only reads to 0.1 mm, it's hard to tell gauge it actually is.
For most of the connections, I used the multi-strand (for better flexibility and strength), except the loop connecting the negatives of A and X (thin enough to have it folded over in the gap between the buttons, so they can move independently of each other without pulling on the soldered joints):
https://postlmg.cc/7Cg3qFqVThe LEDs slot into the coloured parts of the buttons, with their legs bent to come out horizontally though gaps in the tabs that keep the buttons in the right orientation. I have left a mm or two of leg clear, which I have looped the connecting wire round and soldered. I need to keep the remaining legs short so they don't hit the outer edge of the channels in the front shell, but this doesn't leave me much room to get a good solder joint. I thought it would be better to have the rigid legs going through the tabs rather than cutting them even shorter and having flexible wires passing through the tabs and connecting to the legs within the buttons.
I have wires coming round the top (X, Y, - for A and X), side (A, B) and top outer corner (- for B, - for Y) of the board, partly to minimise the run of wires needed between the buttons and the rubber pad beneath, and partly because I now have them individually controlled - my previous parallel-connected version had wires from A and X running diagonally to the corner and I had difficulty getting everything to lie flat enough not to interfere with button presses.
Can you recommend what gauge of wire I should use, muti- or single-strand? Where do you route the wires? Where can you include extra slack length so the buttons can move without pulling on the joints? Would you recommend having the solder joints inside the buttons rather than in the channel around them?
Update: I have used more of the thin wire and rerouted the cables:
