https://github.com/Gualor/garmin-gotchi
Tamagotchi Gen 1 Emulator for Garmin Instinct 3.
https://github.com/Gualor/garmin-gotchi
garmin garmin-connect-iq monkey-c tamagotchi
Last synced: 10 months ago
JSON representation
Tamagotchi Gen 1 Emulator for Garmin Instinct 3.
- Host: GitHub
- URL: https://github.com/Gualor/garmin-gotchi
- Owner: Gualor
- License: gpl-2.0
- Created: 2025-05-27T12:29:47.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-07-13T12:24:06.000Z (11 months ago)
- Last Synced: 2025-07-13T14:31:18.712Z (11 months ago)
- Topics: garmin, garmin-connect-iq, monkey-c, tamagotchi
- Language: Monkey C
- Homepage:
- Size: 2.05 MB
- Stars: 3
- Watchers: 0
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-garmin - garmin-gotchi
README
# 🐣 garmin-gotchi
## Tamagotchi Gen 1 Emulator for Garmin Instinct 3
**GarminGotchi** is a complete rewrite of the original [tamalib](https://github.com/jcrona/tamalib) project (portable Tamagotchi emulator) from C to Garmin's [Monkey C](https://developer.garmin.com/connect-iq/monkey-c/) language, developed specifically for the [Garmin Instinct 3 Solar 45mm](https://www.garmin.com/p/1315317/) smartwatch. It brings your nostalgic digital pet back to life right on your wrist.
## 🎮 Features
- Faithful emulation of Tamagotchi Gen 1 behaviors
- Watch-native graphics with custom black and white bitmaps
- Button-controlled user interface using Garmin's physical buttons
- Sound effects support using Garmin's attention notifications
- Menu to `toggle sound`, `save`, `load`, `restart`, and `exit`
- Persistent pet data via Garmin storage APIs
- Optimized for Garmin's constrained execution model
## 📦 Project Structure
```txt
.
├── Makefile * Makefile script for build and simulation
├── manifest.xml * Connect IQ manifest
├── monkey.jungle * Project configuration
├── resources * Shared resources
│ ├── drawables > Launcher icon bitmap
│ ├── menus > Main menu configuration
│ └── strings > String resources
├── resources-instinct3solar45mm * Device-specific resources
│ ├── drawables > Custom background and icon bitmaps
│ └── layouts > Layout rendering configuration
└── source * Monkey C source code
├── GarminGotchiApp.mc > Application entry point
├── GarminGotchiDelegate.mc > Application button controls
├── GarminGotchiMenuDelegate.mc > Application menu for save/load/etc.
├── GarminGotchiView.mc > Application graphics rendering
├── programs > Tamalib emulator programs
│ ├── tama.mc - Tamagotchi rom
│ └── test.mc - Test rom
└── tamalib > Tamalib code rewrite in Monkey C
```
## ⚙️ Build & Flash Instructions
### 📋 Prerequisites
- [Garmin Connect IQ SDK](https://developer.garmin.com/connect-iq/sdk/)
- [Java Runtime Environment](https://www.java.com/en/download/manual.jsp)
- [Monkey C command line tools](https://developer.garmin.com/connect-iq/reference-guides/monkey-c-command-line-setup/)
- [OpenSSL](https://www.openssl.org/)
- [GNU make](https://www.gnu.org/software/make/)
Alternatively, VSCode IDE with the Monkey C extension can be used instead of the CLI; follow this [guide](https://developer.garmin.com/connect-iq/connect-iq-basics/getting-started/) for step-by-step instructions.
### 🛠️ First-Time Setup
Build and sign executable:
```sh
make all
# or, equivalently
make key # Generates the developer key
make app # Compiles the watch application
```
(Optional) Run in the simulator:
```sh
make ciq # Launches Connect IQ simulator
# wait CIQ to open
make sim # Runs the app in Connect IQ simulator
```
### ⌚ Deploying to Watch
For app deployement on the watch you must sideload the .prg file onto your Garmin device using [Garmin Express](https://www.garmin.com/it-IT/software/express/windows/) or copy it to the device storage manually in developer mode, like so:
1. Enable Developer Mode on your watch.
2. Connect it via USB.
3. Copy bin/garmingotchi.prg to the `GARMIN/APPS/` directory.
4. Restart the watch to launch the app.
### ⚠️ Limitations
- 🧠 **Memory Constraints**: The app operates under tight memory limits, adding even one more class or making too many static variables/methods could result in the app not fitting RAM anymore at some point during execution. ROM is also an issue when adding emulator programs, but this is mostly avoidable using `Lang.ByteArray` instead of `Lang.Array` which will cut down size by 4.
- 🧵 **Thread Watchdog Timer**: The Garmin Monkey C VM enforces a watchdog timer on each thread to prevent them from hanging and crashing the system; therefore, there are only so many emulator steps that we could fit in that time frame. Optimizing the code further could enable us to increase `GarminGotchiApp.RUN_MAX_STEPS` and make the game run smoother.
Despite these constraints, the game can be enjoyed at a slightly reduced cycle speed with all original functionalities.
### 📸 Screenshots
### ⚠️ Disclamer
I am not a Garmin software developer and I mostly work with low-level languages, so a lot of stuff I had to figure out myself and hack my way around to make this port work; most likely there are better ways for running the game smoothly on the watch without issues, I am just not aware of them.
If you are a professional Garmin SW dev and want to share your knowledge or even contribute to the project, it would be very much appreciated!
### 📞 Support
For bug reports or contributions, feel free to open issues and PRs, I will review and respond to them as soon as I can.
For any questions, you can also reach me at: lorenzo.gualniera@gmail.com
### 📜 License
This project is a rewrite of [tamalib](https://github.com/jcrona/tamalib) that is distributed under `GPLv2` license; therefore, all modifications to the original source code require this project to be released under the same terms which you can find [here](./LICENSE).