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

Sep 082011
 

It took long enough, but I finally have some free samples!

They are some Mill Max test pin headers, 2×4, with 1.27mm pitch, which is nice and tiny!

I’m glad I managed to get some samples, mainly because the minimum quantity I could find them in is 98, and at $11 each, that’s quite step, especially since I only really wanted 2 of them.

I’ll be using them as ICSP headers or maybe JTAG (JTAG fits on 8-pins, right??)

UPDATE:

I’ve received more samples! This is fun!

  • 2x 28-DIP ATmega328
  • 4x 32-TQFP ATmega328
  • 2x 100-TQFP ATmega2560
  • 2x 44-TQFP ATmega644
  • 2x 40-DIP ATmega644 (not pictured)

I’m kinda kicking myself for not having asked for some AT32UC3L’s too, since they are hard to come by in Australia and I don’t want to pay $40 shipping from the US. And, also, I’m going to be using them for my next project.

Good thing that I kept the 44pin->dip converter board samples that I received last year, since I can use them on the 644, though since I also have the 644 in a DIP package, it’s not that important.