Ensemble IoT

Ensemble IoT is a PHP framework for building IoT systems spread across multiple devices.

Ensemble IoT aims to make communication between many logical devices , spread across many physical devices, essentially network transparent. Each device has a name, and devices can send messages to other devices that are then actioned.

Ensemble IoT includes a simple Context Broker for working with distributed sensor data, and some pre-built modules for applications that I have at home.

Inter-node communication is achieved over HTTP, although other transports should be fairly straightforward to implement. (WebSockets are an obvious choice!)

Operating Principles

• devices are essentially PHP objects. They can do things on a schedule, and/or wait to receive commands from elsewhere.
• commands are sent from one device to another. They are routed between devices either locally, within a commandbroker, or across devices using an inter-node transport.
• endpoints are transports that allow inter-node communication.
• Discovery of remote devices is done using a registration call to an endpoint, whereby one node tells another node about its local devices.
• If a node receives a command for a device it doesn't know about, it sends the command to a default endpoint - a bit like the default gateway in IP routing.

Running

The main daemon operates as a command line PHP program.

The HTTP API needs to be served somehow - nginx works - and uses shared files to pass data to the daemon.

The API and daemon both load (shared) configuration from files in config, named with the IP address of the node. This way, a single repository can contain config for all devices at once.

Testing

We need a script that can spin up multiple daemons at once, as if they were running on different hosts, and mocking the config/inter-node communication as appropriate.