# Building a HEART-Embedded System: worked guides

Each guide takes one kind of product from day 1 to a HEART-embedded system, step by step, and marks what works today and what you would have to add yourself.

## Built with the reference implementation

| Guide | Product | How HEART runs |
|---|---|---|
| 1. [Air-conditioner controller](AC-Temperature-Controller.md) | An appliance with sensors and a compressor | `heartd` beside the control firmware, on embedded Linux |
| 2. [Photo editing software](Photo-Editing-Software.md) | A desktop or web application | The Core inside the app, as WebAssembly or a Rust library |

Both use the reference implementation in `heart-core-rs/`. The examples they build are in `heart-core-rs/examples/ac-controller` and `heart-core-rs/examples/photo-editor`. Both pass `heartd check`, and both have been run.

## Case studies with a simulator you can run

Each has a simulator in its own folder: one Python file (standard library only) that you run on your own computer, register on [HEART Hub](https://heartcortex.ai/monitor) with the claim code it prints, and watch on your own private page. Each folder's `README.md` covers running it, registering it, its staged faults, its local HEART API, how the code is built and what code to add for a real product, and its end-to-end test. All of them can also be watched live, with no download, under **Demo simulated devices** at [heartcortex.ai/monitor/demos](https://heartcortex.ai/monitor/demos).

| Guide | Product | Simulator | What it shows |
|---|---|---|---|
| 3. [Birdhouse camera](Birdhouse-Camera.md) | A camera in a nest box | [`birdhouseSimulator/`](../birdhouseSimulator/README.md) | Adopted Playbooks zoom out for a crowd and in for eggs, inside an envelope; the infrared light needs a person |
| 4. [Pacemaker](Pacemaker.md) | An implant and its home transmitter | [`pacemakerSimulator/`](../pacemakerSimulator/README.md) | Monitoring only: HEART never touches pacing; a patient's condition is not a device fault |
| 5. [Smart thermostat](Thermostat.md) | A home heating thermostat | [`thermostatSimulator/`](../thermostatSimulator/README.md) | Every change is physical and waits for a person; an AI only suggests (A3) |
| 6. [Greenhouse irrigation](Greenhouse-Irrigation.md) | Pumps and valves for three zones | [`greenhouseSimulator/`](../greenhouseSimulator/README.md) | The brain proposes, the heart decides: a Trial with one approval and automatic undo |
| 7. [Water pump station](Water-Pump-Station.md) | Two pumps run by a PLC | [`pumpStationSimulator/`](../pumpStationSimulator/README.md) | Monitoring only: the PLC and its interlocks run the station |
| 8. [EV charger](EV-Charger.md) | A home charging point | [`evChargerSimulator/`](../evChargerSimulator/README.md) | Monitoring only: the certified controller owns current and safety |
| 9. [3D printer](3D-Printer.md) | A desktop printer | [`printer3dSimulator/`](../printer3dSimulator/README.md) | Monitoring only: the firmware owns heating and thermal-runaway protection |
| 10. [Online shop server](Online-Shop-Server.md) | A web shop: software, not hardware | [`onlineShopSimulator/`](../onlineShopSimulator/README.md) | Self-healing Playbooks (A4); destructive actions always refused |
| 11. [Dog tracking collar](Dog-Tracking-Collar.md) | A GPS collar on a dog | [`dogCollarSimulator/`](../dogCollarSimulator/README.md) | Location never leaves for the monitor site; lost mode runs at once, the LED and buzzer need the owner's confirmation |

The simulators are demonstrations only: not medical, industrial or safety equipment.

## Watching your devices on your own server

Do not wish to use heartcortex.ai? [Run your own HEART Hub server](../ownMonitorServer/README.md): the same open code, on your own machine.