SOURCEFORGE » RALF » 2015 Prototype mission for cubesat

h1. Software developpement

The software we are proposing is a variation of the software proposed in the [[Sputnik strikes back:| Sputnik strikes back]] project, software desgin. 

As them, we are going to retriev on a sensor data, tranform it in a more appropriate format so as to send it by the RF transmitter.

h2. General principle

p. We are developping for an RTOS, a real time operating system. As presented in the generalities //LINK HERE, this kind of software runs on a task driven event basis. That is to say we are creating tasks inside infinite loop (so that they keep running) and a scheduler will be operating the shift between the tasks. 

p. In order for the tasks to release or take the processing power they need, the system rune a priority basis : tasks with higher priority, when they need to process, interrupts tsks with lower priorities ta take control. These high priorities tasks need to release the control in order for the lower priority tasks to be able to run.  This is done by what we call a "context switch" functionality present in the scheduler, and notably in the "OS_Delay()" function that enables the tasks to wait and release the prcessing power to another task.

p. In order to set the timing between the tasks, we will implementflags, which will serve to determine when some functionalities will be accessed in the tasks. These flags have to be set by other tasks to manage the workflow between tasks.

h2. Software definition

p((. h3. Tasks definition

p((. h3. Sequence of events