That last iteration its incredible! Yeah, it has lot of via, but as long as it doesn't interfere with RF part I also think is a nice layout.
One question about the capacitive sensor, does it works with the thick player of plastic that will be the case? I know there are some capacitive sensors able to work as far as 1cm, but don't know how this chip will perform :P On Mon, Jun 2, 2014 at 4:16 AM, Werner Almesberger <[email protected]> wrote: > I'm working towards the V1 board which will, among smaller changes, > replace the wheel with a capacitive sensor and the AT86RF231 with the > CC2543. > > I tried a few different component placements for this. An overview > drawing can be found here: > http://downloads.qi-hardware.com/people/werner/anelok/tmp/v1s.pdf > > > First, I tried the approach where the CC2543 helps the KL26 with its > GPIOs, so that a smaller package with fewer pins can be used with the > KL26. This is in the branch "puppet". The memory card would be > ejected into the battery compartment. > > This is nice and compact, but routing the control signals from the RF > SoC promises to be difficult. I also had second thoughts about having > the two chips interact so tightly, especially since the CC2543 would > not only have to handle control outputs (power on, etc.), but also > some interrupt lines. > > > I then tried to see what would happen if I just adapted the version 0 > design. I also gave the KL26 its own crystal (more about this in a > separate post). > > A first try - branch "large" - looked somewhat promising but I ended > up with very long traces and a few problems with the pin assignment. > > > Next was a more radical attempt to put all major components on the > top layer, to avoid vias. This is in the "coplanar" branch. It looked > pretty good, with one problem: with components as tall as about 2-2.5 > mm on the top, the FPC of the OLED would get bent quite a bit. > > I also moved the battery to the center, to allow for better holders. > More about this later. Last but not least, I tentatively added the > "hard" rfkill switch. > > I almost made this board, but then I chickened out, fearing it might > become too much of an FPC killer. > > > The next attempt, "split", moved everything but the OLED FPC and the > LED to the bottom. I could make it all fit but had to share some > signals, had other pin assignments that were far from optimal, and > the traces to the capacitive sensor took a rather epic journey. > > Naw, too many concessions. > > > Then I decided to face my fears and made a design that wouldn't try > to avoid vias. It's in the "dftv" branch, "Don't Fear The Vias". > > This one places the large chips on the top layer and tall components > (USB, switch, memory card holder) on the bottom. It also places the > memory card such that it ejects into the battery compartment again. > > This worked surprisingly well and I could assign all the signals to > "good" pins and keep delicate traces short. Since the card holder > eats up a lot of space, there was very little room for the USB side, > which also has some of the power supply circuit. Things got too > crowded with the OLED FPC in the same area, so I flipped the OLED and > the FPC now connects at the top edge. > > > I think this looks good enough to try. I therefore merged "dftv" into > the master branch. If anyone wants to have a look, the schematics are > here: > > http://downloads.qi-hardware.com/people/werner/anelok/tmp/anelok-20140601.pdf > > The layout is here: > > http://downloads.qi-hardware.com/people/werner/anelok/tmp/anelok-20140601.png > > > More details about the various designs can be found in > https://gitorious.org/anelok/anelok/source/hw/NOTES > > - Werner > > _______________________________________________ > Qi Hardware Discussion List > Mail to list (members only): [email protected] > Subscribe or Unsubscribe: > http://lists.en.qi-hardware.com/mailman/listinfo/discussion > -- Felix
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