The watch,
before the watch.
Every interaction gets tested here first, in pixels, where changing your mind costs nothing. This is the Essential Watch OS running today, a 128 by 64 monochrome panel driven by the same mode machine the firmware will use.
EMULATOR 1.1 · 128×64 LOGICAL · 3× FULL-RES · HANDJET
Click or tap the watch to focus it.
Controls
| Action | Keyboard | Touch |
|---|---|---|
| Crown rotate up | ↑ | Tap crown, top |
| Crown rotate down | ↓ | Tap crown, bottom |
| Crown press | Enter | Tap crown, middle |
| Button 1, select | Z | Tap upper pill |
| Button 2, back | X | Tap lower pill |
Hold any key or button for half a second for a long press. From the watch face, a long press of the crown opens the menu.
Close to the pixel buffer.
No framework, by conviction. A firmware simulation wants the same shape as firmware, so the emulator borrows the structure of an embedded GUI.
WatchOS class
Holds the drivers: audio, graphics, simulated sensors, input feedback. Runs the frame loop and manages the active mode, the way a microcontroller loop() would.
Mode classes
Every screen inherits from one abstract Mode base: home, menu, stopwatch, timer, alarms, workout, compass, info. Adding a mode is copying a class and registering it.
SimulatedSensors
Mock heart rate, battery, and heading today. On real hardware these become I2C readings, and the modes do not know the difference.
Earlier builds.
Three prototypes came before the emulator on this page. They are frozen where they landed, single files with no shared code, kept because the wrong turns are part of the record.
Emulator 1.0
The baseline. A 128 by 64 monochrome panel, cyan on black, a game loop and a Mode class hierarchy in one HTML file. This is the architecture the current build inherits.
Emulator 2.0
The same panel with a wider mode set: menu, stopwatch, workout, compass, alarms, info. A grey case, a blue OLED, and a mode stack instead of a flat registry.
Emulator 3.0
A large round canvas, touch first, chassis rendered in CSS. It explored more pixels and a finger instead of keys, and earned the conclusion that the 128 by 64 restraint is the product.