Apologies if anyone considers this post off-topic, but I know people here are following the uWatch project.



It looks like I'll have kits available in mid May. I have most of the parts and they should go the assembler next week.



I'm doing a small first batch and am giving MoHPC users first dibs. So I'm after expressions of interest for those who want a kit so I know what numbers there are. You'll go on a list and get access to the order page as soon as the kits come in.



The kit will be US$115+postage for the assembled and programmed PCB, and the rest of the bits to build the full watch. The only soldering required will be the battery holders, all the SMD stuff is done for you.



The rest of the assembly is basically gluing the LCD, front panel, and other stuff in place (you supply the glue). Step-by-step instructions will be on the web site soon.



I have not sorted out the watch bands as yet, so that won't be included in the kit. But I hope to have one to offer for around $15 by the time the kit is available. Alternatively you can use almost any 20mm or 22mm watch band on the market.



The website has more info:

http://www.calcwatch.com


email altzone@gmail.com if you are interested.



Thanks

Dave.

Count me in!!

It looks like it may have a backlit LCD, is that correct?

Cheers, Geoff

I´m very interested.
I want one!!
Iñigo

Hi Dave!

Wonderful! Count me in for the first batch!

I'll have TVM on my wrist when my Hp-81, 92 or 80 are out of grasp!

Congratulations and success!

Etienne

$115 + postage seems well worth it. I would gladly buy one at that price, and would commit up-front with a deposit if required.

(I have emailed separately, but wanted to reply here to drum up 'public interest' as well :^)

Edited: 28 Apr 2008, 3:22 p.m.

Quote:

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Count me in!!

It looks like it may have a backlit LCD, is that correct?

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Yes, it's backlit. But it currently only works in the time/date display mode, not calculator or setup modes. It's also quite dim due to the simplistic circuitry used. But it still lets you see the time in the dark.

Dave.

Quote:

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Hi Dave!

Wonderful! Count me in for the first batch!

I'll have TVM on my wrist when my Hp-81, 92 or 80 are out of grasp!

Congratulations and success!

Etienne

---

Just to be clear, the calculator does not have any TVM functionality.

This is my current list of supported functions:

1/x

X^2

SQRT

LOG

10^X

LOGe

SIN, COS, TAN (DEG/RAD with INV and HYP)

X^Y

e^x

R>P

P>R

// (parallel function)

X!

cube root



All work in either RPN or algebraic mode. Algebraic is the default unless you change it in the setup menu.



The keystroke macro recording mode is also included.



I hope to have a base conversion mode going by the time the first batch ships. But I haven't started on this yet.



Dave.

Edited: 28 Apr 2008, 6:11 p.m.

Quote:

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$115 + postage seems well worth it. I would gladly buy one at that price, and would commit up-front with a deposit if required.

(I have emailed separately, but wanted to reply here to drum up 'public interest' as well :^)

---

Thanks.
No deposit required.
I also won't be taking money until I have the final product in my hands ready to ship.

For those interested in programming or modifying the watch themselves, the source code will be released under the GPL license and is compatible with the free student edition of the Microchip C30 compiler. You need will an ICSP download cable and a suitable PIC programmer. I'm including the ICSP connector in the kit, but you'll have to wire up your own cable to suit whatever programmer you have. I use the Microchip ICD2 programmer, but that's fairly expensive. There are cheaper alternatives around though.

Dave.

Hi Dave,

Thank you for your answer.

Yes I fully understood uWatch is a scientific calc.

In fact, I intend to learn how to program it and try to design TVM functions.

This is the fun of it!

Best regards

Etienne

Dave, it is simply: Great !

For me that I'm struggling to build my own calculator (an HP-15 clone) it is great to see how you solved some of the problems I found myself (I made 2 prototypes):

How to power the LCD
- Your charge pump is interesting (I used a DC-DC converter and powered everything from the same 5V source).

- The keyboard: Those small keys with enough surface to be actually pressed make it more compact, avoiding the moulded plastic top of most calcs, a great idea. (I wanted moulded keys, but they can not be made so easily). And the plate above the keyboard, it is actually a PCB with cut holes, great and thin!.

- No actual cabinet, that reduces size, weight and makes the circuit visible for increased geek factor ! (together with the 2 connectors!

Fantastic!

Did you use binary fp or BCD ? (I use BCD, for the AVR): Do not answe I found it in your description.

Best regards,

Ale

Edited: 29 Apr 2008, 7:04 a.m.

Quote:

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Dave, it is simply: Great !

For me that I'm struggling to build my own calculator (an HP-15 clone) it is great to see how you solved some of the problems I found myself (I made 2 prototypes):

How to power the LCD
- Your charge pump is interesting (I used a DC-DC converter and powered everything from the same 5V source).

- The keyboard: Those small keys with enough surface to be actually pressed make it more compact, avoiding the moulded plastic top of most calcs, a great idea. (I wanted moulded keys, but they can not be made so easily). And the plate above the keyboard, it is actually a PCB with cut holes, great and thin!.

- No actual cabinet, that reduces size, weight and makes the circuit visible for increased geek factor ! (together with the 2 connectors!

Fantastic!

Did you use binary fp or BCD ? (I use BCD, for the AVR): Do not answe I found it in your description.

Best regards,

Ale

---

Those techniques were developed specifically for the watch form factor, although they may also be applicable to a handheld design as well.



The problem with a haldheld calc is that it's designed for fast and easy everyday use. That really means nice moulded keys with the primary functions printed on them.



On first thought, if I was to do a handheld calc prototype I'd look at perhaps using "keyboard" switches with removable covers on them so you could insert professional looking insert sheets with the functions printed on them. Couple that with a suitable bottom half of a handheld box and a similar gloss black PCB front panel to the uWatch, and you might have yourself a decent looking DIY calc using only off-the-shelf parts like the uWatch.



Would be a fun project...



Dave.

Quote:

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Apologies if anyone considers this post off-topic, but I know people here are following the uWatch project.



It looks like I'll have kits available in mid May. I have most of the parts and they should go the assembler next week.

---

Update - PCBs and parts are now all in, boards are going to the assembler tomorrow. Quoted turn-around time is two weeks.

The first batch is almost accounted for, email me to reserve one.
Be the first on your block to have an RPN calculator watch.

BTW, out of curiosity, would anyone be interested in a "belt-clip" version? The same back cover can be replaced with a version that has a integrated belt (or pocket?) clip. Makes it the worlds smallest pocket calculator I figure.

Dave.

Quote:

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BTW, out of curiosity, would anyone be interested in a "belt-clip" version? The same back cover can be replaced with a version that has a integrated belt (or pocket?) clip. Makes it the worlds smallest pocket calculator I figure.

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This would be more interesting to me at least.

- Pauli

I'll see if I can post a pic tonight of the beltclip version.
Also, there is nothing stopping anyone from simply leaving the watch band off and using it with the standard cover either. Slips into any pocket nicely, even a big fob pocket!

Dave.

Dave, I'm also interested. Also, I'm curious what kind of power draw it has and how large of a solar chip would be required to make it battery-free? Certainly would make it a bit larger, but it would be the coolest "green" RPN on the planet.

Chuck

Quote:

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Dave, I'm also interested. Also, I'm curious what kind of power draw it has and how large of a solar chip would be required to make it battery-free? Certainly would make it a bit larger, but it would be the coolest "green" RPN on the planet.

---

It draws in the order of 2mA with the LCD on.
LCD off it drops to <20uA.
The LCD automatically switches off after a preset time period to save power.

A solar panel wouldn't be a viable solution. You'd need some form of power storage to keep the clock running when there is no light, either a supercap, rechargable battery, or a lithium battery. Plus the additional space of the solar cell (the watch is already big enough).
Much easier, simpler and more compact to simply use a lithium battery and replace it every year.

The "Green" aspect would hardly amount to anything. The difference over say a 10 year life would be the manufacture and disposal of say ten CR2032 batteries vs a supercap and a solar cell relative to the overall manufacture and disposal of the entire watch. I think if you did an overall impact analysis you'd find the difference isn't as big as you think it might be.
Also, the manufacturing numbers are trivially small.

A better "green" calculator would be one that used recycled materials and other environmentally friendly(er) manufacturing processes. I believe the Casio FX-260 qualifies as one of these in many respects.

Dave.

Quote:

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I'll see if I can post a pic tonight of the beltclip version.
Also, there is nothing stopping anyone from simply leaving the watch band off and using it with the standard cover either. Slips into any pocket nicely, even a big fob pocket!

Dave.

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The belt clip attachment.

26mm total thickness

Dave.

Count me in also.

Hello Dave!

I´m very interested too!

Wilhelm Loidl

I sent an email after I saw this -- but in case it wasn't clear that I was a forum reader, I am, and I'm interested.

Quote:

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I sent an email after I saw this -- but in case it wasn't clear that I was a forum reader, I am, and I'm interested.

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I got your email Dave, thanks. And all the others too, I didn't reply to reply to most of them unless you had specific questions, but rest assured you are all on the list to get one in the first batch.

Dave.

Dave, I sent you an email via the uWatch site. I don't know if am too late for batch #1, but will wait for batch #2 if need be. Thanks.

Quote:

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Dave, I sent you an email via the uWatch site. I don't know if am too late for batch #1, but will wait for batch #2 if need be. Thanks.

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Hi John
You just made it in, lucky last.



So the first batch is now SOLD OUT. It's been quite popular!

Will have to order a second batch now I think.



Assembled boards are due back mid next week.

Dave.

I'm in for a kit for sure.
Ta
Stefan

I hesitate to mention this, but has anyone posted about the uwatch on slashdot yet?

-cam

Not that I am aware of.

- Pauli