General Operation of the Electrical Interface
The controller is initialized by pressing the Reset button. The “Ready” LED (we used a green LED) will be lit while the controller is in the ready state. At this time, the rocket can be safely loaded into the water column and connected to the switching module. Once the rocket is in place and the water column has been filled to the level predicted by the launch team, the code breaking competition begins. Each team is given the code. If the team who has designed the rocket (the Launch Team) breaks the code first, the computer interface will generate a signal for the swithcing module (the LaunchTeam signal). The activation of this signal will cause the controller to move into the “launch” state. In this state, the controller will light the “Launch” LED (we used a blue LED) and switch the relay, connecting the rocket to the power supply, which will cause the rocket engine to automatically fire. The controller may be placed back into the “Ready” state by pressing the Reset button. If the team trying to prevent the launch (the NoLaunch Team) breaks the code first, the computer interface will general the NoLaunchTeam signal causing the controller to move into the “noLaunch” state. In this state, the controller will light up the “NoLaunch” LED (we used a red LED) and keep the system in this state even when the LaunchTeam signal is received until the Override button is pressed. The Override button will force the controller into the “Launch” State so that the rocket can be fired and the height of the flight recorded. The controller can be returned to the “Ready” state from any other state by pressing the Reset button.
State diagram for the controller