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Since my last big update (11/15), in addition to fixing the critical
issue of the rotary dial not producing numbers consistently, I
wanted to fix as many of the other little issues I mentioned as
possible. This is where I am with it, but there's a TL;DR at the
end:<br>
<br>
-Rotary dial reliability: <b>Fixed.</b> Hubby and I just took this
clip the other day demonstrating the fingerstop position detection
working: <a class="moz-txt-link-freetext"
href="https://youtu.be/IzC9Kba0LX4">https://youtu.be/IzC9Kba0LX4</a>
<br>
The video is showing debug firmware that's just flashing the white
filament LED every time the fingerstop is detected at its end stop,
but that's what was needed. HallSensor.jpg shows the main part of
the actual hardware design change.<br>
<br>
-Reception quality: <b>I think fixed.</b> I updated the
daughterboard design too to improve the internal antenna to a newer
and more capable antenna element. Daughterboard_BA.jpg shows the
difference between old and new. The band coverage of the internal
antenna now better compliments that of the external antenna.<br>
<br>
-Aux. jack: <b>Might be fixed.</b> I learned the reason the
auxiliary headset jack (the TRRS jack) wasn't working is because
common headsets *always* use single-ended audio, (i.e. one wire
connected to the audio source and the other connected to ground) and
the audio codec on the RUSP provides differential output (a speaker
with both wires receiving the audio waveform). I added a
differential-to-single-ended audio output stage to make this
conversion, meaning the built-in speaker and mic are now also
single-ended. See AudioStage.jpg if interested. I don't know if this
new audio stage works or not yet (reason below), but it should.
Also, if you have a EE background and would like to be a second pair
of eyes on the schematic, please email me.<br>
<br>
-LEDs: Because the "meter" LEDs on the side of the phone are
entirely redundant considering the front OLED display is much better
at displaying battery level and signal strength, I decided to turn
most of them "inward" to illuminate the rotary mechanism while it's
turning. Just a neat aesthetic improvement. See NewLEDPositions.jpg.<br>
<br>
-Battery life and speaker phone: <b>Probably both fixed.</b> The
headline for this item is that<b> </b><b>there's no longer a
difference with the early-order beta-test phones.</b> It's all the
newest possible chipset (LARA). If you want to know what this means
and how it relates to the battery and speaker phone issues, by all
means read on:<br>
<br>
The phone was originally supposed to use a cellular modem from
u-blox called "TOBY R-2". Over the course of designing the phone, I
learned from u-blox that the TOBY series was reaching end of life
and that the recommended replacement part is the u-blox LARA-R6. I'd
already procured enough TOBY modems for the first 200 or so orders,
but in the interest of having the best possible phone from the start
I decided to transition immediately to the newest version of the
cellular modem (the ublox LARA-R6) and NOT use any of the cellular
modems that were designated for the early-order phones. Those chips
are now on ebay. This was irresistible to me because the LARA has a
much better low-power mode that doesn't sacrifice detecting incoming
calls, et cetera, and which should at least double the phone's
battery life. It also has pre-set audio codec profiles for things
like speakerphone, which was also giving me trouble with the older
(TOBY) cellular modem. <br>
<br>
The catch: Because of a baud-rate compatibility issue between the
new LARA and the phone's low-power microcontroller, I need to either
somewhat customize the phone's microcontroller's bootloader, or
switch to a similar, pin-compatible microcontroller (i.e. the
ATmega1280, which can run at 16MHz while powered by a lithium
battery, as opposed to the current ATmega2560V, which only runs at
8MHz), which should handle the higher baud rates naturally. So
that's what I'm working on now.<br>
<br>
<b>TL;DR: </b>The first-release of the phone is close to not having
any compromises, but now I have to fix the new problem that was
created by migrating to the newest cellular modem. I'm waiting for
some new parts to arrive and plan to sort through these last
problems in the coming week and get the first orders out the week
after that.<br>
<br>
<b>Final thing</b> for this email: I'm faced with the reality of
having to sustain this company and be able to continue buying parts
for future batches, etc. I haven't, I would say, intentionally
sought pre-order customers before because there just seemed to be
somewhat consistent interest, and with that I've been able to
finance all the development costs with the pre-orders that just
happened to come in. Kickstarter without the Kicstarter so to say.
But, I'm starting to stress a bit about this as there are still long
lead times on certain parts for future batches, and this requires a
"front heavy" spending profile (yikes I'm turning into a business
person). <br>
<br>
Once phones are actually in customers hands the dynamic will be
different and I'll feel OK about actually <i>trying</i> to sell
these, but for now I'm not entirely sure what to do. At a certain
point I'll need to NOT be working out of a basement (I'm not sure if
this is even legal), and hire a couple people to help with ongoing
manufacturing. Making this transition from tiny business to
less-tiny business is a known tripping point for small business
development from what I can tell, but I guess I'm open to
suggestions.<br>
<br>
~Justine<br>
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