My pal Sean Ragan got a Seek thermal imaging camera add-on for his phone. He was excited to try it out, but the micro-USB jack on his phone is "upside-down," which means the camera faces the same way as the phone's screen. In his effort to correct this problem, he tried a variety of USB cables, and learned quite a bit about the way USB cables are wired. It's a worthwhile read for anyone who wants to make things that use UBS connectors.
About this time I discovered, to my chagrin, that micro-USB extension cables come in various flavors depending on whether they are for charging/syncing the phone or allowing it to serve as a USB host (“OTG”). The hackers and engineers reading this will immediately understand my frustration at this idea—it’s an extension cable, for f*ck’s sake: All the contacts at one end should be connected to the corresponding contacts at the other end, with continuous conductors between them. Is that really too much to ask? Omitting certain conductors just serves to fragment the market and create artificial demand for multiple purchases from individual users. Nonetheless, on a lark, I bought the complementary “charging” cable and discovered that, unsurprisingly, it does not work either.
He finally had to hand-make a connector to get it to work.