PAVAS Controls and Display

PAVAS has two control methods.

The first method is via six buttons located on the front panel. Commencing from the left, they are Select,Left,Up/Down, Right and Reset. The Left, Up, Down and Right buttons are used to move the underline cursor on the display. The Reset button is used to immediately abort any process and restart PAVAS. This last button should be used with caution since data is not saved.

The main function of the Left, Right cursor movement buttons is to select a digit in the display. Once the digit is highlighted, the value can be changed with the Up or Down buttons. If the Ten's digit is selected, then the value is incremented by 10. This fast technique simplifies editing and entering data. PAVAS always commences with a default value and a default cursor position to start any editing process. It also imposes limits for the minimum and maximum values. These limits are selected to to be beyond the performance of any surface bound vehicle.

The Select button is used to make a choice or set a value.

The second control method is a remote digital joy stick. This has four directions of motion that correspond to Left, Up, Down and Right. So this can be used to emulate the front button functions. If the joystick is pressed, then the Select function is actuated. The Joystick remote is very simple and convenient to operate since it can be controlled with a thumb, is fast and, does not require access to the front panel. Joysticks can be daisy chained without limit so, a number of joysticks can be used in the vehicle. There is no Reset function on the joystick. A Targa Florio optimized remote joy stick is described here.

There is no undo or confirm processes in PAVAS since these tend to complicate and slow down data entry. If a mistake is made or changes are required, the procedure is to go back and renter or edit the value. On a Select button press, PAVAS saves that value to non-volatile Flash memory. The Flash memory lifetime is several million cycles so it will not wear out in a PAVAS lifetime.

The PAVAS display consists of a back lit LCD with a contrast adjustment potentiometer located on the front panel. There are two lines of 16 characters in the display. A shade peak is used to reduce reflections or the impact of outside light. During events, the main purpose of the display is to provide information for the navigator. The design does not anticipate the driver looking at the display. To save interactions, the display uses a rotating message format. Here each parameter is displayed for two seconds and then the display line rotates to the next parameter message. If a specific parameter is required, the left and right buttons will abort the current display and move in the direction selected. Once this has occurred, the display persistence increases to six seconds for that parameter. After which, it reverts to the two second time. The use of a remote joystick is very useful here to manipulate the parameter display.