ZealMod

Open firmware for the Zeal Smart Timer speedcubing timer, and the program that builds it.

The timer stays a timer: ZealMod lives next to the stock firmware and opens on a long button press. Inside there is a cover-flow menu, games, a clock, a calendar, settings. You choose which programs go in and how it all looks, and you can write and install your own programs and themes without rebuilding anything.

🎬 Watch ZealMod in Action

Русская версия

What you need

• the timer itself and a USB cable with data wires (a charge-only one will not do);
• Python 3.9 or newer;
• once: pip install esptool pyserial.

Nothing else — no compiler, no drivers. The timer's socket is wired to the native USB of its ESP32-C3, so the computer sees it on its own.

Getting started

git clone https://github.com/ARTEMIY-FCC/ZealMod zealmod
cd zealmod
./zealmod studio          # or: python3 studio/zealmod.py studio

A window opens (a page in your browser; the program runs on your computer and sends nothing anywhere). Then:

1. the timer's port shows up in the top right — a green dot means "I see it";
2. on the left, tick the programs you want and drag them into the order you want them in the watch menu;
3. in the middle pick a theme and a menu style, on the right the button mapping and the firmware language;
4. flash the timer — half a minute later the watch reboots with ZealMod.

save .gbl gives you the image as a file: share it with a friend, and they can install it with the same program (or with zealmod flash file.gbl).

Before your first flash it is worth pressing flash backup — a full dump of the factory state, just in case. You can go back without it too: restore stock.

Using it on the watch

action	how
open ZealMod	hold the top button for 1.5 s (configurable)
move around the menu	◀ ▶
launch	▲
leave a program	hold its exit button (shown in the program list)
back to the timer	▼ in the menu

The clock, the high scores and the settings survive a power cut — they live in a flash sector, not in RAM.

Your own programs and themes

.zm is a program (a game, a clock, anything), .zt is a theme. Both are ordinary zip archives. To install someone else's, just drag the file onto the Studio window: it checks whether the program fits your version of ZealMod, shows its size and adds it to the list.

To write your own:

./zealmod new app mygame   # a C scaffold
./zealmod emu mygame       # run it on your computer
./zealmod pack mygame      # build mygame.zm

Any path works, from anywhere: ./zealmod pack mygame from the repo root and ../zealmod pack . from inside mygame/ do the same thing.

That part does need a compiler (riscv64-elf-gcc) and SDL2 for the emulator — but only for the author. Whoever installs the program needs none of it: a .zm carries ready machine code, and Studio places it in the image and links it against the core itself.

More: docs/module.md — how a program is built, docs/api.md — the full API reference, docs/theme.md — how a theme is built, docs/architecture.md — how all of this works inside.

Command line

Three ways to call the same program:

• ./zealmod <command> — the wrapper in the root of the repository (zealmod.cmd on Windows). Nothing to install.
• python3 studio/zealmod.py <command> — the same thing spelled out. Mind that this path is relative to where you stand: from inside mygame/ it is ../studio/zealmod.py.
• zealmod <command> — a real command anywhere in the system, after pip install -e studio/. It looks for the kit next to itself and then up from the directory you are in, so it works from a subfolder too; --bundle /path/to/zealmod points it at one by hand.

zealmod devices          what is connected over USB
zealmod build --all      compose an image with every program
zealmod flash [image]    write it to the watch
zealmod check game.zm    will this program fit
zealmod pack folder/     build a .zm from sources
zealmod new app|theme    scaffold one
zealmod emu [folder]     run it on the computer
zealmod backup           full flash backup
zealmod studio           the window

--lang ru switches the firmware texts to Russian; the Studio window has its own language selector.

What is in the repository

zealmod      the command itself (`zealmod.cmd` on Windows) — a wrapper around
             studio/zealmod.py
work/        firmware: the ZealMod core and the sources of the built-in programs
studio/      ZealMod Studio and zealmod — everything that touches the image
modules/     the list of built-in programs (builtin.json)
themes/      themes, packed into .zt files
examples/    a scaffold for your own program
dist/        the built kit: core, modules, themes, stock image
docs/        how it is put together

Troubleshooting

• zsh: command not found: zealmod — from the repository, call it as ./zealmod ...; to get the bare zealmod command, pip install -e studio/.
• python3 studio/zealmod.py ... can't find the script itself (can't open file '.../studio/zealmod.py') — the path to zealmod.py is relative to your current directory, not to the repo. If you're inside a module folder like mygame/, that's ../studio/zealmod.py, not studio/zealmod.py.
• studio says the port is busy — it now takes the next free one and prints it, and if the window is already open on the same kit it just shows that one. To find what holds the default port: lsof -nP -iTCP:8777 -sTCP:LISTEN (then kill <pid>), or start elsewhere: ./zealmod studio --port 8800.
• emu says it needs the firmware sources — it prints the directory it looked in. work/host/host_sdl.c ships in the repo, so this usually means the clone is incomplete (a partial download, a git clone --depth/sparse checkout, or files removed by hand), or that you are running an installed zealmod outside any checkout — point it at one with zealmod --bundle /path/to/zealmod emu.

Careful

• ZealMod overwrites the ota_0 partition — the very place the stock timer firmware lives in. The factory image can always be put back: it is in dist/base/zeal-stock.gbl, and restore stock writes it there.
• Studio checks that the stock image in the kit matches the one the mod was built against. If your timer runs a different version it will say so; stop and take a flash backup first.
• We patch somebody else's firmware with three four-byte jumps. That is exactly as reliable as the version match — see studio/zealmod/profiles/.

License

MIT for the ZealMod code. The stock timer firmware belongs to its manufacturer and is kept here only so that you can go back to it.