Editing UWatch


[[image: CalcArmTimeSmaller.jpg | thumb | uWatch on wrist showing time]]

== µWatch unofficial FAQs ==

The uWatch is an RPN and Algebraic scientific calculator watch that you can build yourself.
The software is open source under the GPL license [http://sourceforge.net/projects/calcwatch/ at Sourceforge].
I'm assuming you've already read the [http://www.calcwatch.com/faq.htm official uWatch FAQ], so we'll jump right into some more technical details.

== OSWatch ==
: See [[Open Source Watch]]

The OSWatch and the uWatch are both open-source wristwatches that are fully user-programmable.

== display ==

The [http://www.calcwatch.com/history.htm history of the uWatch] mentions the 53mm x 20mm compact 16x2 line LCD that convinced David L. Jones that the uWatch project was actually doable with off-the-shelf components.
If you are doing low-level programming of the uWatch, such as making "custom characters", you might want to look at [http://www.electusdistribution.com.au/products_uploaded/QP-5519-2.pdf the datasheet] (via [http://www.calcwatch.com/forum/viewtopic.php?id=37 "Moon Phases"]).

Alas, that original display pulls about 2 mA, more power than anything else on the uWatch -- even the CPU uses less power (at 250 KHz). That's the main reason the current uWatch cannot [http://www.calcwatch.com/forum/viewtopic.php?id=42 run the display continuously] (like a standard watch), but much be explicitly "turned on" every time you want to read the time.

The current uWatch2 rough draft seems likely to use the
[http://www.newhavendisplay.com/index.php?main_page=product_info&cPath=3_113&products_id=1824&zenid=goih7iect56osjf64srb498qi4 Newhaven NHD-C12832A1Z-FSW-FBW-3V3] 128x32 Pixels display.
Which uses less than 100uA which would enable a continuous display watch. The "white LED backlight" uses 30 mA at 3.0 V but is still very usable at much lower currents.

Proposed displays:
Limited to less than 10 mW of power when updating the time once a second (FIXME: reduce this limit and prune higher-power displays when this list gets too long):
In no particular order:

* [http://www.newhavendisplay.com/index.php?main_page=product_info&cPath=3_113&products_id=1824&zenid=goih7iect56osjf64srb498qi4 Newhaven NHD-C12832A1Z-FSW-FBW-3V3]: 128x32 pixel display, white LED backlight, 41.4mm x 24.3mm (current top runner)
* [http://www.newhavendisplay.com/index.php?main_page=product_info&cPath=21_96&products_id=2072 Newhaven NHD-12864WX-T1TFH# Graphic LCD]: 128x64 pixel display, white LED backlight, 38.0mm x 26.4mm. Power: 3.3 V at 0.18 mA typical (when 32 mA backlight is off)
* [http://www.crystalfontz.com/products/12864ap/index.html CFAX12864AP1 Graphic LCD]: discontinued, apparently replaced by CFAX12864T1.
* [http://www.crystalfontz.com/product/CFAX12864T1WFH.html CFAX12864T1-WFH Graphic LCD]: 128x64 display with EL backlight. Power: 3.3 V at 0.18 mA typical; (the EL backlight version seems to require less power than the [http://www.crystalfontz.com/product/CFAX12864T1TFH.html white LED backlight version]; but how much power is that exactly?).
* [https://www.crystalfontz.com/product/cfax12864t1tfh-graphic-lcd-128x64-display#datasheets CFAX12864T1-TFH Graphic LCD]: 128x64 graphic LCD display with white LED backlight. Power: 3.3 V at 0.18 mA (when 3.5 V at 32 mA backlight is off)
* [http://www.avesodisplays.com/products/index.html card display]: 6 digit, 7 segment display module designed to fit inside a credit card. lightest-weight display of those on this list; adequate for 4-function calculator watch. Doesn't seem to show enough information for a scientific calculator.
* [http://www.sparkfun.com/commerce/categories.php?c=76 Sparkfun LCD displays]: the color graphics LCD cell phone displays look relatively low power and are extremely well documented -- some of them are under $20.
** [https://www.sparkfun.com/products/10168 Graphic LCD 84x48 - Nokia 5110]: power: the datasheet says 2.7 V to 3.3 V at 0.24 mA typical; but the [https://learn.sparkfun.com/tutorials/graphic-lcd-hookup-guide "Graphic LCD Hookup Guide" tutorial] says 2.7 to 3.3V at 7 mA (?) (when the 3 V at 100 mA white backlight LEDs are off)
** [https://www.sparkfun.com/products/11676 Serial Miniature OLED Module - 1.5" (μOLED-128-G2-GFX)] : 128 x 128 resolution, 65K colors, 1.5". Power: 5 V at 60 mA typical when on, 0.1 mA when all pixels black (?). Includes microSD socket.
** [https://www.sparkfun.com/products/11377 Serial Miniature LCD Module - 1.44" (uLCD-144-G2 GFX)] : 128 x 128 resolution, 65K colors. Power: 5 V at 40 mA typical when on, 0.5 mA when all pixels black (?). Includes microSD socket.
** [https://www.sparkfun.com/products/256 Basic 20x4 Character LCD - Black on Green 5V] : Power: 5 V at 1.5 mA typical (when the 4 V at 250 mA LED backlight is off)
** [https://www.sparkfun.com/products/13192 SHARP Memory Display Breakout - Silver Monochrome (1.3", 96x96)] : Power: 12 uW (?) 2.7 V to 3.3 V updated at 1 Hz. Apparently several libraries: [https://github.com/olikraus/u8glib U8glib: A graphics library with support for many different monochrome displays]; [https://github.com/pabigot/bsp430/blob/next/src/boosterpack/sharp96/u8g_bsp430.c]; [https://github.com/adafruit/Adafruit_SHARP_Memory_Display]; ...
* ...
* ... ''Have you seen a display that would work on a wrist calculator? Please add it to the list here!'' ...

Some threads discussing diplays:
[http://www.calcwatch.com/forum/viewtopic.php?id=7 "Hardware Stuff » Why not a smaller LCD..."],

== buttons ==

The buttons are crucial for a calculator watch.
It is difficult to compromise between:
* fast typing speed:
** it's much faster to have lots of buttons, so you can directly push a button for "tan" than to scroll through some soft menu searching for it. 
** large buttons are generally faster to rapidly punch than tiny, closely-packed buttons
* physical size: 
** We want something that is not too heavy and bulky to wear on the wrist. This means lots of large buttons are not going to happen.

The first uWatch prototype used surface-mount buttons.
The original uWatch for sale uses the (through hole!) Panasonic EVQ-PJG05Q switch for its buttons.
[http://www.calcwatch.com/forum/viewtopic.php?id=121]
([http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P12237SCT-ND current price])

* ''please tell us about other buttons that would be appropriate''
* ... capacitive touch "buttons" ? ...
* ...

== processor ==

The processor is, perhaps surprisingly, not a crucial choice.
In the last few years, several companies have released processors that meet the stringent low-power and other requirements (''which are????'').
In theory, since most of the software is written in the C programming language, it is theoretically easy to port the software to a different CPU.

The original uWatch uses the 16 bit Microchip PIC24FJ64GA004.
It uses 50uA at 32KHz, ... ''(FIXME)''... uA at 250 KHz.

Other proposed processors have been discussed on this thread:
[http://www.calcwatch.com/forum/viewtopic.php?id=66 "Hardware Stuff » Ideas for Mk2 watch"].

...
the Microchip "Extreme Low Power Microcontrollers"
claim to have "Real-time Clock/Calendar down to 500 nA".
http://www.microchip.com/xlp

Nate gives some low-power tips in
[http://www.sparkfun.com/tutorials/309 "Adventures in Low Power Land"].

Arne Martin Holberg and Asmund Saetre.
[http://www.atmel.com/Images/doc7903.pdf "Innovative Techniques for Extremely Low Power Consumption with 8-bit Microcontrollers"].

== Other open-source wristwatches ==
: ''(FIXME: should this list go on some other page?)''

"IS YOUR WEARABLE TECH TOO SUBTLE?"
"My 3D-printed Big-Ass SmarTwatCh"
http://zackfreedman.com/2014/07/19/my-3d-printed-big-ass-smartwatch/
https://hackaday.com/2014/07/19/wearable/
"Arduino-based, has a breathalyzer, and is not subtle!"

"Introducing the F*Watch, a fully open electronic watch"
https://hackaday.com/2014/10/17/introducing-the-fwatch-a-fully-open-electronic-watch/
"The watch is powered by a 500mA LiPo battery. All the tools that were used to build it are open source (FreeCAD, KiCad, GCC, openOCD, GDB) and our readers may make one by downloading all the source files located in their repository."
http://www.ohwr.org/projects/f-watch/repository

"DIY OLED smart watch"
https://hackaday.com/2014/07/07/diy-oled-smart-watch/

"Make your own smart watch"
https://hackaday.com/2014/02/17/make-your-own-smart-watch/

"a bracelet that allows you to strap your raspberry pi to your wrist."
http://www.3ders.org/articles/20130604-lighting-up-graduation-with-an-awesome-3d-printed-web-connected-led-cap.html
http://www.damngeeky.com/2013/06/11/11891/3d-printed-control-my-cap-is-perfect-to-light-up-your-graduation-night.html

"a working prototype of Fallout's Pip-Boy 3000"
http://singularityhub.com/2014/05/08/inspired-by-video-game-makers-construct-wearable-wrist-computer-for-space-explorers/
(appears to be more functional)

"A fully 3D printable Pip-Boy 3000"
http://www.3ders.org/articles/20130630-a-fully-3d-printable-pip-boy-3000.html
http://www.geeky-gadgets.com/diy-3d-printed-fallout-pip-boy-3000-wearable-created-10-09-2015/
(far more "realistic", painted to look "weathered")

"GyroPalm"
http://3dprintingindustry.com/2015/07/14/3d-printed-gyropalm-seeks-to-control-your-electronic-world/
includes infrared and inertial measurement sensors.
"the GyroPalm is open source and 3D printed"

"Smartlet: go on, wear your iPhone on your wrist"
http://www.thecrowdfundnetwork.com/smartlet-go-on-wear-your-iphone-on-your-wrist/

"DIY Digital Wristwatch"
http://blog.zakkemble.co.uk/diy-digital-wristwatch/comment-page-1/
https://github.com/zkemble/NWatch

"Homebrew smartwatches"
by: Brian Benchoff
http://hackaday.com/2015/08/12/hackaday-prize-entry-homebrew-smartwatches/

"Get up, stand up. with a little help from the mindfulness bracelet"
by: Adam Fabio
http://hackaday.com/2015/06/16/get-up-stand-up-with-a-little-help-from-the-mindfulness-bracelet/
(it technically keeps time, but it doesn't display time visually ...)

* http://hackaday.com/tag/watch/
* http://hackaday.com/tag/wearable/
* http://hackaday.com/tag/smartwatch/
* http://hackaday.com/tag/wrist-watch/
* http://hackaday.com/tag/smart-watch/

"Ben Heck’s Oscilloscope Watch"
https://www.youtube.com/watch?v=HOqBInoDEhE
modifies a [[oscilloscope#Xprotolab - Miniature Oscilloscope and Waveform Generator | Xprotolab]]
to make
a functional [[o'scope]] worn like a wristwatch.
Places battery pack in the strap rather than under the display,
and other techniques, to reduce maximum thickness,
to achieve the goal of "keep watch under 1/4" thick (about 7 mm)".
The firmware and PC interface software are open-source.


== further reading ==


* [http://www.calcwatch.com/ µWatch]: World's First D-I-Y Scientific Calculator Watch
* For general discussion about the µWatch, see the [http://www.calcwatch.com/forum/ uWatch Forum].
* [http://www.calcwatch.com/forum/viewtopic.php?id=66 post Ideas for the entirely hypothetical Mk2 watch]
* [http://www.calcwatch.com/forum/viewtopic.php?id=139 "Hardware Stuff » WBL: watch based laboratory"]
* [http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=142807 "What is the smallest full trig calculator in production?"]

''Late breaking news: there is now [http://www.calcwatch.com/wiki another µWatch wiki]; is that the Official µWatch wiki? Feel free to move all the content on this page to that wiki. --[[User:DavidCary|DavidCary]] 15:58, 19 November 2009 (UTC)''

: Oops, that wiki has gone offline. So we'll keep this wiki page at Open Circuits. --[[User:DavidCary|DavidCary]] 23:08, 4 September 2011 (UTC)

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