Stupidly Small eInk Font

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I have the new Watchy eInk watch. It has a cute little screen with a resolution of 200x200 pixels. How much text can we cram in there?

A typical watch face looks like this:

Watch with a big USB cable plugged in.

My new watch face is far superior and looks like this:

A chunky eInk watch with a ridiculously small font.

That's using the GNU Unifont - which works brilliantly on tiny devices.


  • Download the GNU Unifont
  • Download and compile HarfBuzz
  • Run the HarfBuzz Font Subsetter
  • ./hb-subset unifont-15.0.06.ttf abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789\!\"\£\$\%\^\&\*\(\)\-\_\=\+\@\~\'\#\,\.\/\?\:\;\<\>\\\| -o latin.ttf
  • Convert the output to AdaFruit's GFX format using truetype2gfx (set the Font Size to 5 points for about the smallest you can reasonably go. But Font Size of 8 is a better compromise between size and readability.)
  • Follow the tutorial to create a new watch face
    • NOTE If you put the font file in the same director as the .ino file, you need to include it using #include "latin5pt7b.h"
  • Compile and upload to your watchy via USB.

A tiny pixelated font showing the time.


Next Steps

I dunno. Make it bounce around? Print a Shakespearean sonnet? Give me some suggestions!

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2 thoughts on “Stupidly Small eInk Font

  1. says:

    You could display many timestamps simultaneously (every minute this hour, or ±30 minutes, etc.) and use color inversion to highlight the current time.

    Or make it a progress bar, where the time moves through the hour or day.

    Or maybe show recently-edited Wikipedia pages. Maybe you'll see something interesting.

    Or StackExchange hot network questions.

    Or check out what productivity/PIM apps were popular on the old 160x160 PalmOS devices, maybe there's inspiration to be had there.

  2. says:

    @Edent Given how far back your blog covers, you could build an "at this hour" feature, selecting a blogpost from history that you posted around the current time and display the title, publishing date and intro


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