There are several projects I’m playing with to which I would like to add downstream USB ports. The big problem is that even so-called single-chip hub solutions require a multitude of support parts. Microcontrollers can’t handle this. I already asked. I really don’t want to re-engineer these parts for each project. I want to be able to just drop something into a breadboard and go. So, how about putting all these parts onto a 40-pin DIP? Is anyone else here interested in something like this?
Right now I’m looking at a Texas Instruments TUSB2046B hub chip http://www.ti.com/lit/gpn/tusb2046b. I should have a schematic and/or a board pattern to show off in a few days.
Here’s something I fiddled together this evening http://frotz.homeunix.org/microhub/. It requires fewer than 32 pins, but I think the result will be at least the size of a DIP-32. Obviously this needs some more work, but please, take a look and let me know what you think. The .sch file is from gEDA and requires the TI symbols from http://www.gedasymbols.org/user/david_griffith/.
I’ve actually used the TUSB2046 in projects before, it works fine but is only a Full (12MB/s) speed device. I did it about 8 years ago when USB hubs were a lot more expensive, and computers didn’t have very many USB ports. I needed to have a USB microcontroller and a USB webcam at the end of one cable. These days, I would definitely have skipped the hub integration and just used an off the shelf hub, or a separate cable running back to the PC.
One of the things I intend this for is to add downstream ports to this: http://www.schatenseite.de/dulcimer.html?L=2 for connecting a mouse. Yes, I like the way Sun and Apple did their keyboards, but I like the feel of my Model M.