Added test code for robot movement based on US
Removed extra range offset for sensors 0 and 5
Hardware has been changed so they are now the same as all other sensors
Tidied up code for ultrasound detection, etc.
Also tidied up some old bits of code
Changed how sensors are selected for sampling
Now allows for an array of sensors to be specified
Added obstacle detection function
Returns if an item is detected within Xmm of a sensor
Added constants for robot motor direction
Reduced the number of US samples from 400 to 200
Quicker to sample and still sufficient for small distances
Changed robot motion to navigate basic maze
Turns in the direction that is clear when meets obstacle
Moved MicroBlaze code into DDR
Not enough space in BRAMs any more
Reduced constant offset in US range calulation
Added function to get range from US sensor
Added constants for US sensor positions
Added state machine for robot driving control
Robot avoids walls, turns in the correct direction at a junction
Merge branch 'driving'