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Comment by pharke | Hacker News Reader

I don't see why the contacts on the demonstrated devices would be any more vulnerable to the real world than the port on an iPhone. I'm not sure these devices would be mass market since some skill is required to understand and use the software but they would absolutely have a good run at serving the same size market as 3D printers. They could even work hand in hand with 3D printers by providing the 'brains' for prototyped projects.

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Besides the wiping, these connectors are missing two other features: ESD protection and connection-sequencing.

Most user-facing connectors have a metal shield around them connected to frame ground. The idea is that any ESD shock goes safely through this first instead of to a sensitive data line.

Connection-sequencing ensures that the ground and power is connected before data lines are. If you look inside a cable-side USB connector, you'll see that the inner two wires (data) are recessed a little so that the power connectors go first. A device that is connected without power can (through its ESD protection circuit) attempt to draw power from data lines... this can cause damage because most data lines can't supply the current to power the entire device.

You don't know if they ESD protection or not. There are loads of tiny little ESD protection ICs/diodes that can handle many inputs. Just put them very close to the connectors and you should be good to go from an ESD perspective. You don't need a metal shield around everything to protect against ESD.

Every USB device connected to your PC right now probably has a little ESD protection IC in it. Usually sitting right next to the USB connector (as close as possible).

I think you could effectively connection sequence this interface? Though it'd be electronic sequencing rather than a physical one like on usb ports, you could make it so that a particular non-symmetrical set of pins need to be in a certain position before power is delivered through any power pins. Assuming there are multiple grounds, it could be continuity through all the ground pins that would allow power to flow.

And since the snap-in boards are all rigid you don't really need to worry about the possibility that contact will be made in like.. a rolling way. Either the pins are on the board or they're not.

But I'm not an EE, just a hobbyist, so maybe there's something I've missed there and what I'm thinking is way more complicated than I think.

Connectors are usually built so there is a small amount of "wiping" as they seat, which will scrape off oxides or dirt. They will also have just the right amount pressure to balance longevity versus contact resistance. The pockit connectors may not balance these factors well (depends on what's making contact from the modules - I couldn't find the details readily). Regardless they won't have wiping, which isn't mandatory but is the cheapest way to keep connections reliable.

So likely they won't have nearly the cycle life of USB-C but do they really need to?

If wiping is the main problem you could just wipe them with a cloth or some other device. They are exposed and highly visible after all.

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