So im having a really strange issue with some ultra sonic HC SR04 based sensors, the cheap ones on ebay.
So here is the deal I have 5 sensors, I tested all 5 on a Propeller based DevBoard. They all worked fine. The sensors read that my wall was 115cm away. I also put my hand in front of them moving it back and forth and the readings appeared accurate.
I then pluged the sensors in to an Arduino, put my hand in front of them and the readings seemed fine. When I moved my hand the sensor said 0cm and wouldnt detect my wall. The Arduino was in the exact same spot as my Propeller BOE. So I then took a book and tested the range of the Arduino, I couldnt get more than about 50cm. This is odd that my range drops when using an Arduino...
Im guessing it may be a software, I downloaded the new ping library along with it demo. This library claimed to be better than the standard one and supports the ebay sensors.
Anyone use these ebay ultrasonic sensors with no issues, anyone have an idea why my range is cut down so severly when using Arduino.