Anelok: rework plan, battery update, left-shift, Anelok in China

Werner Almesberger werner at almesberger.net
Sat Feb 14 13:35:08 UTC 2015


Just a few minor items for this week:

- I made a plan for reworking existing Anelok boards to make the
  whole system run at 3.3 V:

  http://downloads.qi-hardware.com/people/werner/anelok/tmp/boost-rework.pdf

  More details:

  https://gitorious.org/anelok/anelok/source/aeaccf8b538ae2f46c894dea5afe7037b7359ce6:doc/boost-rework/README

  This looks reasonably simple. Losing the Vsys pad isn't nice but
  not really a problem at this stage.

  In the boost-rework branch, I changed the schematics and the layout
  to reflect the modifications, and they still agree with each other.
  I haven't actually implemented the rework yet, so there may still
  be surprises, such as the idea not working at all.

- meanwhile, the battery is busy discharging and has just passed the
  300 hours mark:

  http://downloads.qi-hardware.com/people/werner/anelok/tmp/cr2032-300h.png

  Not sure if the slight drop towards the end is a first sign of
  weakness or whether this merely reflects the cooler weather of the
  last couple of days. We'll see next week or so.

  The effect of temperature is noteworthy. If we assume that the
  difference between highs and lows is about 10 K, that would mean
  a temperature coefficient of roughly 5 mV/K.

  This may not seem like much but the voltage change caused by a
  temperature difference of 10 K would then be the same as that
  caused by a current difference of 2.5 mA or 20+/-10% of the
  expected idle current (display on, LED off, not doing much else).

- items on the screen are now arranged in a more logical way in
  left-handed mode. Here is an illustration:

  http://downloads.qi-hardware.com/people/werner/anelok/tmp/handed.pdf

  On top is the usual right-handed configuration. So far, switching
  to left-handed simply rotated the entire screen content. This
  caused the position marker (the little white blip) and the icon bar
  to end up far from the finger, which looked a bit counter-intuitive.

  The bottom drawing shows what it looks like now: position marker
  and icon bar get moved to the left and the main display area starts
  after them.

- last but not least, the folks at Canaan Creative (Xiangfu et al.)
  have made a few Anelok boards. Some first impressions:

  http://downloads.qi-hardware.com/people/xiangfu/anelok/tmp/brd-with-UBB-front.jpg
  http://downloads.qi-hardware.com/people/xiangfu/anelok/tmp/brd-with-UBB-back.jpg
  http://downloads.qi-hardware.com/people/xiangfu/anelok/tmp/Anelok-booting.jpg

  Looking great ! Plus, it proves that the available design information
  is sufficient to build working devices from it, i.e., that I didn't
  hold back or simply forget something.

- Werner



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