I hacked an 8 sensor parking sensor unit found on Ebay for about $50. This type of unit has 1 cm resolution. The details are in the code comments. Commented out sections of code show the development process and may be useful to those hacking other types of parking sensors. The input data was pulled from the data line between the control box and the display.
sonar_parking_5B.ino (3.52 KB)