DevGuide/Settings

Settings is the generic mechanism that allows to get/set the value of any variable of the embedded code.

Overview

Problem Statement

Given an embedded program in C, we want a way to set/get the value of any variable without having to write any ad-hoc code.

• The variable can be of any base type (e.g. uint16, int32, float) or a structured type (not implemented yet).
• The variable can be directly accessed (declared in a header) or used through a pair of accessors (e.g. SetVar/GetVar).
• Typically the variable is manipulated through a graphical user interface on the ground station.
• The graphical interface can manipulate the variable in a different unit (e.g. the embedded code uses a binary fixed point representation)

Solution

The solution used in Paparazzi consist in describing the variables in a high level xml file, which is then processed to generate embedded code and used by the graphical user interface to display the suitable controls.