Realistic plan for our own FreeCalypso phone

Mychaela Falconia mychaela.falconia at
Sun Oct 30 18:47:16 UTC 2016

Hello again everyone,

Before I address David's comments specifically, let me point out one
already existing DIY phone project using a home-made wooden case:

You will notice that the pictures shown in different pages depict
slightly different versions of this DIY phone - it appears that there
have been several different versions created.

The guy who created this wooden marvel wrote in one of the comments
responding to someone's questions about practical usability:

> Thanks! I've been using one of these for more than two years now.
> It works well, as long as you're okay with the limited functionality.
> (There is a phone book and alarm clock, and you can send and receive
> both phone calls and text messages.) The battery lasts about a day and
> a half or two days. The phone fits reasonably well in a pocket.

The catch of course is that in terms of electronics and software, this
DIY phone is nothing more than an Arduino wrapper around a commercial
off-the-shelf (i.e., 100% closed and proprietary) cellular modem module,
i.e., a dumbphone version of GolDeliCo-style projects.  Ours in contrast
will have a Calypso chipset with FreeCalypso firmware directly
controlling everything from the radio to the LCD.  I am hoping for a
better battery life too, more like the existing historical commercial
dumbphones made with the Calypso.

But in terms of the physical construction and what the finished product
will likely look and feel like, this wooden DIY phone is my inspiration.
I was originally thinking of using plexiglas rather than wood as my
case material, but I haven't really put any significant thought into
it yet - so perhaps wood might work better after all - I don't have a
particularly strong preference either way.

Back to my original point though: the core of my idea is to divide
what would otherwise be an impossible task (for a tiny marginalized
community like ours) into manageable bite-sized pieces.  Of course it
would be wonderful to have our own FreeCalypso phone whose physical
construction is no different from the Pirelli or any other commercially
made dumbphone of such class.  Such a commercial quality, factory-
produced FreeCalypso phone is still my ultimate dream goal, and if we
ever get a really rich sponsor, we might make it happen.

But what I need first and foremost is a bare board for development.
Just a bare board and nothing more.  Not to carry it in my purse (even
an oversized and very loosely packed lady's purse won't be a gentle
enough environment for a completely bare board to survive in), but to
use it on a lab bench for software development.  Development of the UI
and other handset functionality layers which could also be ported over
to the C139 and Pirelli targets, as I've already explained before.

But I am already looking ahead to what will happen next.  Suppose we
build this bare board - HSMBP for Handset Motherboard Prototype.  I
then use this board to get the firmware into shape, and we have a bare
board phone prototype with a working hands-free loudspeaker, a really
awesome 176x220 pixel color UI and a better-than-Pirelli's USB-serial
interface.  What next?  The logical next step for people like David
would be to hobble the UI from the rich 176x220 pixel size down to the
measly 96x64 pixels that can be displayed on the C139, and port the fw
to the latter.  I am not saying I won't do that part - I most likely
will - but will such a hobbled port, moving from our own awesome
prototype to the very crippled C139, make me happy as a user and as
the proud mother of FreeCalypso?  Answer: hell no!

After all of the blood, sweat and tears that I have put into this
project, I would want some *real* fruit from it: I would want to have
a device in my purse that exercises the *full* functionality of
FreeCalypso firmware, complete with the hands-free loudspeaker, the
large LCD and the cool USB-serial port with a fully native AT command
interface, as opposed to the hobbled subset of this functionality that
can be ported to the C139.

In short: a C139 port will probably still happen, and it will probably
be good enough for casual users like David, but it won't be good enough
for the Mother of FreeCalypso.

So what would be good enough for my own motherly demands?  Again, the
ideal dream answer would be our own FreeCalypso phone that is
physically constructed just like the commercial dumbphones of similar
class - but I fear that I might not have the budget for such a feat.
After we have our HSMBP, if we wish to turn it into a commercial
quality phone product, we would likely need 3 quite costly steps:

1. Hire a mechanical and ergonomic designer to create the fully
   detailed mechanical design for the phone product;
2. Modify the motherboard, changing the physical form factor from the
   simple rectangular used in the bare board prototype stage to
   whatever the final mechanical design calls for;
3. Produce the plastics to finish the product.

This is where the wooden or plexiglas hacky case idea comes in as a
cost-saving shortcut.  Not only would it eliminate the cost of the
plastic moulds (5 digits from what I've heard), but it would also
eliminate the need to create a professional mechanical design and to
remake the motherboard in that new shape - instead the wooden or
plexiglas case would be built around the by-then-existing prototype
version of the motherboard.

David wrote:

> To me this does sound interesting; one thing I loath about smartphones
> and other modern electronic gadgets is the throw-away and upgrade culture.
> I suspect that this plan might do away with some built in frailty?

I really have no way of comparing "modern" gadgets (smartphones etc)
to the historical dumbphones like the Pirelli DP-L10.  I don't know
anything about the "modern" stuff, but I don't see any "built-in
frailty" in the Pirelli DP-L10 - hence if we had the monetary means to
recreate something like the Pirelli, I would most certainly go that

> It's gonna look weird though and it might be uncomfortable in some
> jurisdictions to be using a gadget that may attract attention (not for
> good reasons) and may be of dubious legality. nb - I am not a license
> worshipper (although I like the GPL) and IMO it's absurd that, provided
> it's use does not disrupt networks, a project such as freecalypso might
> be of questionable legality.

I've been toying with the idea of shipping finished products in very
prominently marked packaging:


But maybe I won't go quite *that* far. :-)

> >Male users may find this hack-phone to be a bit more difficult to carry
> >in their pockets though -
> Again - this rules it out for me

Perhaps my original assumption that a phone in a home-made case won't
survive in a guy's jeans pocket was too pessimistic after all,
considering the experiences of the wooden DIY phone's creator and
other non-dress-wearing, non-purse-carrying geeks who have apparently
used these phones and carried them in their pockets.

We can probably put a piece of clear plastic over the LCD so we won't
have the problem of the LCD breaking from exposure to harsh pocket
environments, but I do expect the protruding antenna to be a delicate
part.  This is the antenna I plan on using:

I already have 50 of these antennas in my stash, and I got a really
good deal on them: I only paid $75 for this lot of 50 antennas.  I
bought them directly from the manufacturer in Taiwan; normally one
would have to buy a minimum of 1000 pieces (or maybe it was 10000, I
don't remember), but they were nice to me and let me buy just 50 of

Anyways, this antenna will be screwed onto the threaded SMA connector
on the motherboard (search for female SMA connector to see pictures),
and the main body of the antenna will protrude out of the top of the
"finished" phone.  The takeaway for the user is to never allow this
protruding antenna to be hit: any impact to this antenna will have a
high chance of breaking the motherboard.  If you are lucky, only the
SMA connector will fall off and will need to be resoldered, but I'm
afraid that a hard enough hit could break the PCB itself (it will only
be 1 mm thick, the standard thickness for cellphone PCBs) - and that
eventuality would completely destroy the motherboard, the most
expensive part.

Well, OK, I am just thinking out loud at this point - perhaps we'll
find some way to reinforce this part of the assembly.

> > Thus if some members of our
> >community still desire usable FreeCalypso fw for the C139 or for the
> >Pirelli (no loudspeaker, no ring, vibrate only as discussed before),
> >it will be much easier for us to produce such firmware *after* our own
> >FC phone, rather than before.
> that would be good!

As I've said before, the first step, before we can do anything else,
will be to build the bare board prototype version of the FreeCalypso
phone with a 176x220 pix LCD, and use it as the platform for general
(target-independent) FreeCalypso handset firmware development.  After
that the project can bifurcate in two directions:

* For users like David who would rather use an existing phone hw unit
  with feeble capabilities than a much richer but physically fragile
  FreeCalypso device, create a hobbled 96x64 pixel UI.  The reduced-
  size UI would be the only real work with this approach; once a
  reduced UI has been made, creating ports for the C139 (piezo ring
  and vibrate) and for the Pirelli (vibrate only, no loudspeaker)
  would be trivial.

* For more devoted users like the Mother, pursue the wooden or
  plexiglas case idea so I can carry the crown product of FreeCalypso
  in my purse.

Does it make more sense now?

Hasta la Victoria, Siempre,
Mychaela aka The Mother

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