Check out the SM-EW90-A PCB! Some really tiny surface-mount stuff on it, like in a phone.
First go at wiring it up
A pair of wires runs back into the steerer and up through the compression plug to join the wires coming from the frame up through the steerer. This join has to be unsoldered to get the stem off, since there's no room for a plug under the top cap. Initially, another two pairs of wires was running forward into the bars, the extra pair for the remote A-junction button. Finding a suitable connector for four wires was a PITA. Surface-mount micro USB jack gave barely more than a pinprick-sized area to solder onto
But with the aid of my phone on a tripod running a magnifier, I did it by employing ye olde Ultra DMA HDD ribbon wire. Of course, it promptly shat the bed during assembly with the hotglue and heatshrink.
