Eric Rogers of Hawaii built this ranger to warn him — via FM radio — when he was about to bump into another car when backing into a tight parking space.
The Park Ranger is an ultrasonic-ranging prototype, based upon the Arduino and the Amani64 CPLD Shield, designed to assist drivers who are backing into tight areas. The ranger uses ultrasonic pings to measure distance to the object behind and indicates this distance by sending audible tones to your FM radio. Optional panel-mount LEDs offer visual aid for calibration as well as warning drivers behind you.
The intention of this project is to demonstrate the Amani64’s ability to serve as a rapid-prototyping tool for applications typically covered by proprietary modules. While a commercial ultrasonic-ranging module could be used in this project, the Amani64 is used in instead to tailor the system to our exact needs. The user can drop in blocks of IP, whether open-source or their own, to create a custom application over which they have full control and ownership. A CPLD-based prototyping board is useful for any application that requires logical circuits, whether they be parallel or sequential, that space, cost, and vendor-delivery times are a concern.