Anelok: battery, display errors, evolution update
werner at almesberger.net
Mon Feb 23 09:47:41 UTC 2015
- not to belittle the pure joy and excitement of watching paint dry,
but monitoring a battery's epic journey towards inevitable doom is
so much more rewarding:
So last week's drop was caused by the cold weather, not the battery
showing first signs of weakness. Now that summerly temperatures are
back, so is the battery voltage. To be continued ...
- then there is an ugly truth I hadn't revealed yet: sometimes, the
display of Anelok would look like this:
I thought that this may have been caused by timing issues in the
communication between MCU and OLED, but I was a little worried by
me already having verified the timing some time ago without
finding any problem - which would then suggest a more fundamental
Well, while playing with the slider, I noticed that this sort of
pattern would reproducibly occur at the same positions when
scrolling. As we know, if you can reproduce it, you can fix it.
So I did ...
It turned out to be a missing sanity check in my bit blit
function, which allowed it to attempt to draw things that were
completely off-screen. With that fixed, I haven't seen any more
such corruptions, and I sleep a lot better now :)
Note that this is different from the signal integrity issues
caused by voltage mismatch between MCU and OLED. That still needs
solving, but it's pretty clear what's happening there.
- I've updated the hardware evolution diagram:
The previous version (April 2014, how time flies) is here:
- CPU: added the "dual processor" (KL16+KL26) combo as future
- USB device: added using a Micro B receptacle (instead of Micro AB)
as something to consider.
- slider: while a bit more tuning will be needed, it looks good enough
nowadays that I think we can safely bury the wheel.
- RF-kill: the brute simplicity of shorting RF VDD to ground shall be
the way to go.
So this leaves testing operation on CR2032 as the last major open
- meanwhile, Xiangfu sent these pictures:
The second one shows that the capacitive slider now works on these
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