CSE 595 Lab #1

1. CSE 595 Lab #1 Dodge Caravan Electronic Locking System Steve Pruitt Jan 13, 2000

2. Dodge Caravan Electronic Locking System System Features • Electronic locking system on all 5 doors Two front doors have electronic switches which lock all other doors Two rear passenger doors have interior mechanical locks only Rear door has key and interior mechanical lock All doors lock when car exceeds 15 miles per hour • Alarm system Activates when doors are locked Alarms (horn and flashing lights) activate when doors are opened without keys or remote • Remote Controls all locks and alarm system • Basic Design drawbacks: • Locking and alarm system activates on front doors without keys or remote thus allowing keys to be locked in car. • Alarm system only activates when doors are opened. Thieves can enter through window or “smash and grab” items left on the seat. • Designer Viewpoint • More convenient to not have to lock with keys or remote. • Sonic (glass break) alarm activation is too expensive

3. Unlock Lock Panic Dodge Caravan Electronic Locking System The Remote Unlock Button: Press once to unlock drivers door Press twice to unlock all doors Lock Button : Press to lock van Panic Button: Press to activate alarm Press again to deactivate alarm

4. Dodge Caravan Electronic Locking System Remote Problems: • When the unlock is pressed only once, or twice in rapid succession, only the driver’s door is unlocked, since this is a 7 passenger van it is usually the case that more than the drivers door needs to be unlocked. Pressing twice is the usual requirement. • In the dark, it is difficult to remember (and impossible to read) which button unlocks/locks the door • The panic button is too accessible, setting off the alarm by accident is too easy. • When the alarm is activated, the only way to shut off the alarm is to press the panic button on the remote, there is an inherent delay of around 2 seconds before the alarm is de-activated. This delay causes the user to believe that the alarm has not been de-activated so it is pressed a second time, activating the alarm again. It usually takes 6 or 7 attempts at pressing the panic button to deactivate the alarm. Designers viewpoint: • To save wear on the mechanical parts and reduce battery power consumption allow the user to unlock only the drivers door. • Visually more appealing to have lock and unlock buttons side by side. White on black will allow most people with good vision to read buttons in low light. • Good selling point. For personal safety, the panic button is very visible and impossible to miss. • To save cost, have only one button for activating and shutting off the alarm. Once the alarm is activated, complete a cycle of horn honking and light flashing before checking if the alarm has been turned off. (event processing)

5. Dodge Caravan Electronic Locking System Alarm System The alarm system is activated when: • The key is out of the ignition • The doors are locked with the remote or • One of the front doors are locked manually while they are open. • Problems with Alarm System • If the alarm is activated while someone is in the car, the alarm will activate when they open the door. There is no way for someone inside to shut of the alarm without the remote. • Visibility (feedback) of the alarm being set is poor, in a 2 inch high recess in the dash behind the steering wheel. • Designers Viewpoint • Once the alarm is activated, it can not be turned off by anyone without the key or remote. • It looks “cool” when the indicator lights are placed in a recess behind the wheel. Alarm Activated