Software

The full software documentation can be found here outlining the classes and unit tests.

A brief description of the behaviour is as follows. Communication between the PHP web interface and the main c++ code is established through a temporary file, where data is being read/written, requiring only a single thread. However, this can also be achieved with two threads. The first one (LocalThread) would be responsible for the local control of sensors and actuators while the second (WebThread) ensures the communication with a PHP web interface hosted on an Apache web server. A C++ wrapper (written by Bernd Porr under the GNU General Public Licence) can be used to implement multi-thread programming and an I2C lcd library ((C) Kaj-Michael Lang) was adapted to display content on a 16x2 display.

The sampling rate is set to 1 Hz. There is no need for buffering of data as the sampling rate is low, thus post processing is also unnecessary.

Low level implementation happens on userspace as sampling rate requirements are low.