I now completed board #2. It has one unexplained problem, namely that the crystal oscillator doesn't oscillate, but besides that, it seems okay.
Fortunately, I can do most things also with the RC oscillator. It's just a bit less accurate (relevant for timekeeping) and a bit more power-hungry (bad for the battery and for measurements). But I can play with all those things on board #1. This is what the complete assembly looks like: http://downloads.qi-hardware.com/people/werner/anelok/tmp/brd2-assembled-top.jpg http://downloads.qi-hardware.com/people/werner/anelok/tmp/brd2-assembled-bottom.jpg A bit of rework is visible at the bottom: - the debug connector that's still needed because I haven't made a proper fixture yet, - a 100 kOhm pull-up on nRESET (long yellow wire) that I added when experimenting with SWD. It doesn't really seem to have any effect, which is basically what I expected. - the Vrf/Vsys swap near the rfkill switch. This will go away with the next PCB version. I also didn't place the memory card holder because a) I don't need it at the moment and b) there may be the risk of it shorting traces running underneath it. I connected the main board with the daughter board with four small wires (a bit thinner and more flexible than a ribbon cable): http://downloads.qi-hardware.com/people/werner/anelok/tmp/brd2-boxed-b2b.jpg This is baord #2 in the case: http://downloads.qi-hardware.com/people/werner/anelok/tmp/brd2-boxed-bottom.jpg And this is it showing the current login screen (may change): http://downloads.qi-hardware.com/people/werner/anelok/tmp/brd2-boxed-login.jpg The blue tint of the OLED is an artefact of my camera. It gave me the choice between having the perfectly white OLED look blueish or having the perfectly white paper look yellow. Ah well ... This is the first time that I fitted an assembled board into that case, and I found a few issues: - the silo capacitors are quite tall and need more space. One can see the bay I dremeled below the display. - the OLED's FPC needs more room to bend. I also increased this space a bit it's still extremely crowded. Making the case about 2 * 0.5 mm wider (the display is centered, so if I widen the case on the cable side, I also have to widen it on the non-cable side) should lead to more reasonable accommodations. - the battery bumped into the bottom shell. Not sure why it did this now - it seemed to fit without problems when trying the daughter board alone. Again, a bit of dremel solved this. - as expected, the rfkill switch is very difficult to reach. I should probably make a proper cap and move the switch a bit away from the edge. A minor detail. The capacitive slider is now the main source of trouble. It acts fairly erratically. Not sure whether this can be solved by better filtering or whether I need a different sensor layout. - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
