The Project Trailblazer engineers started with a collection of high-level requirements. Nine of these addressed safety and the Operations Department's need for automation. In this chapter, the engineers developed a system integration infrastructure using bash, nc, Apache, and MySQL, and then implemented and tested scripts for temperature data, image data, and lift access control. For each solution, the engineers developed an area within the infrastructure.
The temperature collection, storage, and distribution scripts form the foundation for data storage and presentation. Using gnuplot along with database queries forms a powerful visualization tool for representation of field data. The scripts the engineers developed for temperature data can easily be extended to handle lift monitoring, guest messaging, and race timing.
The image collection scripts introduce an innovative mechanism for target board autoconfiguration. Similarly configured field devices coupled to a database can dynamically create location-specific information. Using this approach in applications that have large numbers of field devices dramatically reduces configuration complexity and deployment time.
The access point scripts control field hardware that is based on database data values. These hardware control scripts can be extended to control music playback and snow-making equipment.
The combination of bash scripts, nc, Apache, and MySQL creates a rich system integration development environment. With the database as a centerpiece for integration, implementing system-wide applications is a matter of simple scripting. You can see an example of this by counting the number of executable lines in the access control scripts. In 22 executable lines of code, a complete access control application fulfills the guest authentication system requirement. The other scripts shown in this chapter are similarly simple and short. Simplicity makes systems reliable. Use of bash, nc, Apache, and MySQL greatly simplifies system development, and embedded Linux makes all this possible.