Webapplications are the future user interfaces. Numerous features speak in favor of using them to interact with embedded systems. Irrespective of whether the webapplication is thought for fast and easy access to embedded systems or to replace an extensive native PC application – several advantages speak for the use of webapplications.
The application is located in the flash memory of the device and is therefore available whenever needed. Distribution via data carrier or download from the internet is not necessary.
It is independent of PC operating systems and version conflicts between embedded firmware and PC application do not occur.
Whether highly efficient webapplication in controller ROM or an comprehensive alternative to native PC application in the Look & Feel of web 2.0 – SEVENSTAX Webserver is designed specifically for the requirements of embedded systems which allows a straightforward integration of web interfaces in embedded systems.
SEVENSTAX Webserver is connected to various file systems via the SEVENSTAX Virtual Filesystem. Web resources can be easily transferred to ROM of microcontrollers by generating source-code modules using the SEVENSTAX Resource Generator. At the same time HTML-files are optimized (by removing all redundant characters). Also integration of external flash components (e.g. SPI-Flash) is supported. In addition, a flash image with integrated lookup-table can be generated using the SEVENSTAX Dir2Flash.
Furthermore, file systems (e.g. FAT-FS) are fast and easily attached to the SEVENSTAX Virtual Filesystem. Thereby, affordable and large data stores, for example SD cards with adequate storage can be connected.
SEVENSTAX Webserver allows handling of (ZIP-) compressed resources. Webapplications often contain static data such as design elements, language files, graphics, formatting, help text, scripts etc. Those files can be compressed and stored to the embedded system (e.g. controller ROM) to save resources. In addition, the transfer of data is accelerated. Unnoticed by the user those files are then automatically decompressed by the browser during the download.
The integrated browser and system recognition allows identification of the web client and adaption of the transferred data. Thus, for example a mobile phone receives reduced data, optimized to its display size and data transfer capacity.
SEVENSTAX AJAX contains the following components:
AJAX Framework for development of web applications for embedded devices
AJAX framework offers a level of communication for generation of JSON requests and processing of JSON responses for web applications. Additionally, this includes a comprehensive example application. The implementation is designed to fit highest operation safety, high browser compatibility and minimum memory footprint. Open source components weredeliberately avoided. Therefore, this software can be stored safely and efficiently to the ROM of the embedded system.
On the side of the embedded system SEVENSTAX AJAX extends the SEVENSTAX Webserver by the possibility to generate and process JSON telegrams. Via a simple API the exchangeable data is connected to the application.
SEVENSTAX RESTful API - extension for HTTP for XML interfaces
SEVENSTAX RESTful API is an extension for SEVENSTAX Webserver for XML based interfaces. Representational State Transfer (REST) offers a stateless interface for exchange of XML formatted data via HTTP. XML elements are directly accessible by URL. Data request using GET and sending of data using POST is supported. The data is processed by the SEVENSTAX XML streaming parser/generator.
XML streaming parser and generator
The implementation is optimizied for the requirements of embedded systems.