What is SDL? — SDL Project

One simple definition

A Software Defined Laundromat is a laundromat in which machines and supporting equipment are represented as software assets with standard capabilities, commands, states and events.

Why “software defined”?

Traditional integrations often place hardware details directly inside the POS, backend or mobile application. A machine may be identified by a board ID, relay channel or proprietary topic. That works initially, but every hardware change spreads through the software stack.

SDL moves those details behind a stable software boundary.

Application request
    start_cycle(machine.d2, 30 minutes)

SDL Edge decision
    select adapter → validate safety → execute locally

Adapter implementation
    Modbus / UART / GPIO / legacy MQTT

What SDL standardizes

Identity

Sites, devices and operational assets have separate, stable identities.

Capabilities

Assets declare what they can do, including constraints.

Commands

Requests use business intent such as start_cycle.

Events and states

Applications receive observable facts and normalized operating states.

What SDL is not

It is not a particular controller board.
It is not a new name for an MQTT topic convention.
It is not limited to SkyWash Cloud.
It does not require modern smart machines.
It is not a promise that every device exposes identical functionality.

A practical example

A customer selects Dryer D2 for 30 minutes. The POS reads the dryer’s declared constraints and sends a standard command. The local edge verifies that the asset is available, the duration is valid and the command has not already been executed. The adapter then performs the correct machine-specific action and reports whether the dryer actually entered the running state.

The POS does not need to know whether D2 uses three relay pulses, a Modbus register or a vendor UART command.

Who benefits?

OperatorsChange components without rebuilding the whole platform.

ManufacturersExpose capabilities through a consistent integration boundary.

Software teamsBuild POS and management applications against stable concepts.

IntegratorsDeploy mixed hardware with clearer diagnostics and migration paths.

Relationship with SkyWash

SkyWash initiated SDL based on its experience operating connected laundromat infrastructure. SkyWash provides the first reference environment and may offer commercial products built on SDL.

SDL itself is intended to remain an implementation-neutral architecture that other providers can adopt independently.