Postby vputz » May 02 2013, 2:00 AM
VDX: I'll see what I can do... not sure I can come up with a good way to package everything nicely, but I'll think about it. You'd have to flash the chip yourself, though.
Kenyee: Actually as it turns out the footprint I used didn't have solder mask, so I can't blame the PCB folks. But this was the footprint adapted from Adafruit's 32u4 breakout board, so I'm going to ask if they really don't have solder mask on their 32u4 chips.
The microUSB port has the contacts barely visible with my microscope, but it's hard to get the soldering iron under there (I can wedge it between the pins and the casing, so I can heat and reflow the pins, but it's hardly accessible). I haven't found any that don't have the pins pretty much underneath. I asked around and one guy suggested [url=http://www.farnell.com/datasheets/44939.pdf]these[/url], which still have the pins mostly underneath but do have legs which fit in holes on the PCB, which would help with alignment and also provide a little strain relief. If I can find a better one than that, I'll give it a try, but with the first batch of 20 I'm going to just do my best and see what I get.
Since I have boards on order and one set of cases/stencils built, I'll build these as the first small batch since they should function just fine and I don't want the boards/cases to be a total loss, but I'll plan a revision; I'm pretty sure I can drop the length under 5cm, which would be only a mildly tight fit but drop the board cost a little through places like itead/seeed who have "max 50mmx50mm" boards pretty cheap... although on the current revision it does look a little more crowded as I added some thtrough-hole pads to make pogo-testing the USB port easier and possibly giving access to the TAP pins for boundary scan. I could use tag-connect for the boundary scan, though, and I'm not convinced the USB pogos are worth it for testing since they would just test the board, not the USB connector. And 2-sided SMD would be much tricker for me since I can only use the hot plate for one side and this is labor-intensive enough already that I can't afford to do any real hand soldering on each one. Contract assembly would be one option, but I didn't sell all that many of the original OrbShield so I almost certainly wouldn't have the volume to make that worthwhile here.
Edit: Sigh... yeah, I can get it under 50mm. Needs a lot more vias and I'll have to move the USB test pads to just solder pads underneath (and probably doing the tag-connect for TAP since I can't imagine anyone but me using it) but it should work and be very pretty... there's JUST enough room to put USB-ATMega-ADM232-DB9 since it's going from 2.5" to just under 2". I'm still selling the rev1 boards, though!