I’ve spent the last couple of evenings designing an OpenHardware USB 2.0 1-port hub tentatively called the ColorHub (although, better ideas certainly welcome). Back a bit: What’s the point in a 1-port hub?
The finished device is a Cypress 2 port hub internally, with a PIC microcontroller hard wired onto the other “fixed” port. The microcontroller can control the hub and the USB power of the other “removable” port, so you can simulate an unplug, replug or hub reset using a few simple commands. This also allows you forcefully reset hardware that’s not responding, and also allows you to add hardware tests to test enumeration and device removal. With the device it is trivial to write a script to replug a device 5000 times over one evening, or re-connect a USB device that’s not responding for whatever reason. The smart hub also reports when USB devices are connected to the downstream port, and even when they have not enumerated correctly. There could be commands to get the status of that and also optionally wait until those things have happened.
The other killer feature for me is that the microcontroller has lots of spare analog and digital IO, and with two included solid-state MOSFET relays you can wire up two physical switches so that no user interaction is required. This means you can test hardware that has these kind of requirements:
- Remove USB plug
- Press and hold buttons A&B
- Insert USB plug
- Release buttons A&B
It would be fairly trivial to wire up the microcontroller ADC to get a rough power consumption figure, or to set some custom hub descriptors; it would be completely open and “hackable” like the ColorHug.
I’ve made just one prototype and am using it quite nicely in the fwupd self tests, but talking to others yesterday this seems the kind of device that would be useful for other people doing similar QA activities. I need to build another 2 for the other devices requiring manual button-presses in the fwupd hardware cardboard-box-tests and it’s exactly the same price to order 50 tiny PCBs as 5.
The dangerous question: Would anyone else be interested in purchasing this kind of thing? The price would be in the £50-60 range, so certainly not cheap, but this is really the cost of ultra-small batches of moderately complicated electronics these days. If you’re interested, send me an email (richard_at_hughsie_dot_com) and depending on demand I’ll either design some nice custom PCBs or just hack together two more prototypes for my own use. Please also tell me if something like this already exists: if so I can save some time and just buy something that someone else has built. Comments welcome.
