Jan 222012
 

So, I got my boards back, got the components ordered in, and I’ve assembled a couple of them.

They don’t work.

Kinda. The micro runs whatever code I put on there, the LED’s blink if I tell them to, but it doesn’t like the USB part. I plug it in, and my computer chucks a dummy spit saying that the “USB device is not recognised, bro”.

I got it working on the breadboard, the exact same code. And apart from a few extra LED’s (that aren’t currently turned on), there’s not much more to the circuit. I have verified all traces, all paths, checked for any bridges, etc. I just don’t know what’s going on.

I’m posting this up to see if anyone can help me debug the sucker and maybe tell me what’s going on. I’m including the schematic, the board layout, the eagle files and a high-rez photo of the current state of the board.

Note, since this board is Rev1, I know I screwed up a couple of things. Most importantly, the 1.5k resistor, R5, should have been connected to the D- instead of D+, that’s been fixed by soldering R5 directly to the “correct” place. Also, the ISCP header, I’ve mislabelled GND/VCC (I know, I know!), so on the board it’s crossed out (but the pins are in the correct spot). I’ve put 22pF capacitors for the crystal instead of 18pF as a different test (this is the second board I assembled to rule out “burnt component” issues).

Here’s the deal. If you are able to point out what I’ve done wrong, I’ll send you one of my blank PCB’s.

Schematic:

Board layout:

Populated board (no switches):

Eagle Files:

uKb_v1.1

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