Watch display

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(link to related articles, etc.)
(yet more low-power displays)
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[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.
 
[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.
 
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.
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 +
There's some discussion of some of the screens considered for the first iteration of the Open Source Watch at http://oswatch.org/details_screen.php .
  
 
Proposed displays:
 
Proposed displays:
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* [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.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.
 
* [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)
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** [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://learn.adafruit.com/nokia-5110-3310-monochrome-lcd Adafruit: Nokia 5110/3310 Monochrome LCD tutorial]
 
** [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/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/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/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]; ...
 
** [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]; ...
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* ...
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* [https://www.adafruit.com/products/1673 Adafruit LCDs & displays] has a huge list; a few of them are low-power enough for an always-on wristwatch display (have I missed any?):
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** [https://www.adafruit.com/products/1393 "SHARP Memory Display Breakout - 1.3" 96x96 Silver Monochrome"] : Power: 12 uW (4 uA at 3.3 V with 1 Hz data refresh)
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** [https://www.adafruit.com/products/250 Graphic ST7565 Positive LCD (128x64) with RGB backlight + extras - ST7565] : Power: 3.0 V at 1 mA (when the 5.0 V at 120 mA backlight is off) (What exactly is the difference between this and the [https://www.adafruit.com/products/438 "Graphic ST7565 Negative LCD (128x64) with RGB backlight + extras - ST7565"]?)
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* [https://www.adafruit.com/products/398 "RGB backlight positive LCD 16x2 + extras - black on RGB"] and [https://www.adafruit.com/products/399 "RGB backlight negative LCD 16x2 + extras - RGB on black"]. Is this really 2.7 V to 4.5 V at 0.3 mA ? (When R, G, and B LEDs are turned off).
 
* ...
 
* ...
 
* ... ''Have you seen a display that would work on a wrist calculator? Please add it to the list here!'' ...
 
* ... ''Have you seen a display that would work on a wrist calculator? Please add it to the list here!'' ...

Revision as of 15:13, 6 December 2015

The display is perhaps the most critical part of a wrist computer such as the uWatch and the Open Source Watch.

The 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 the datasheet (via "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 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 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.

There's some discussion of some of the screens considered for the first iteration of the Open Source Watch at http://oswatch.org/details_screen.php .

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:

Some threads discussing diplays: "Hardware Stuff » Why not a smaller LCD...",

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