Drone Following Project #13: State of Grace

Work on the "Lakitu" ROS package has began! I'm trying my best to make headway, but unfortunately, I'm also ill at the moment. Currently I'm working on making the Arduino state machine launch the Drone via rosserial. In order to do that though, I'm slowly realizing I could modify my Arduino sketch in a slight manner in order to greatly increase the efficiency of how the two objects communicate. For the time being, the Arduino is constantly broadcasting it's state, and the program is constantly receiving it. As I was implementing this, I realized that this is quite inefficient, if you consider what all is going on in this manner:

• /Lakitu/Device_State is constantly sending out messages regarding states.
• The ROS package is constantly receiving these messages.
• The ROS package is constantly evaluating what to do with these messages.
•  The ROS package is constantly sending out messages to drone topics such as "/ardrone/takeoff" and "/ardrone/land"

The problem is that we always want the drone to be aware of what it should be doing, but not be bogged down with too much information. Therefore I propose we take a step back and modify the Arduino sketch to now send out two messages, the original and a new boolean message that signifies if this is the first change to a new state. This adds only a slight amount of added stress on the Arduino in order to take a large amount off of the ROS node-- which quickly becomes bungled as the 'communicator' for all aspects of the program. This will reduce our complicated web of 'if' statements constructed from handling the state machine to a much simpler series that will only ever be evaluated if it is the first spin of a new state.

After this has been handled, I'll be working with first just getting some strings on the ROS terminal to match these states, then the Drone's LEDs, and then, finally takeoff and landing (if I can find the space to safely do so). From this point I'll be moving on to handling the IMU's data and orientation, and then GPS.

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Additionally, I'll be working on making things more uniform. The device will follow the topic convention of

/Lakitu/Device/<topic>

And things on the ROS end will be 

/Lakitu/<topic>