The software monitors current status of the washing machines at the point of service. When the user selects desired mode of operation, the software calculates its price according to the configured schedule. The user can then deposit required amount at the point of service by using a banknote acceptor.

The software obtains configuration of a point of service from the cloud server. This includes list of modes for each device, and price of each option depending on time of day and day of the week. Any status change is immediately reflected on the display and communicated to the cloud server. The operator of the system can check current status of any point of service at any time. When required the operator can take necessary action, for example activate or deactivate an option, adjust price etc.

Architecture

The centre software runs on a cost-effective LinkIt Smart 7688. While providing basic functionality, there is enough performance to run the application. The board runs a custom-built embedded Linux-based operating system, specifically configured for the application to run efficiently.

This allows to lower development and maintenance costs by conveniently employing available high-level services: mature system libraries, reliable filesystem for data storage, Wi-Fi hotspot for local communication, easy access to GPRS mobile modem for Internet access, wall clock with automatic DST adjustment and time synchronisation.

The board contains built-in Wi-Fi which is conveniently used as a hotspot to which the washing machines connect automatically when powered up. No preliminary configuration is required: when a new device is connected, the software automatically discovers it using Neighbour Discovery Protocol and determines its type using application protocol (Modbus). The device list is communicated to the cloud server, where the system is configured using web interface.

• Comms: Modbus TCP; REST
• Languages: C++
• Operating system: customised openwrt