United Kingdom
Asked — Edited

Ultrasonic Sensor Reads 255 Constantly

I've been trying to use an ultrasonic sensor to use on my JD robot but the output is constantly 255 regardless if there is something in front of it or not. The voltage going into the sensor is 4.3 volts. It was purchased in December 2016 so all the parts are fairly new although the ultrasonic sensor has never worked.

All other sensors appear to be working. Thanks in advance for anyone who can help.



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It's either wired wrong or it's dead... Check the wiring and try another port(s)... Are you using it with the kit's voltage regulator? If so make sure the voltage regulator is also plugged in the right way around... You may blow that if you plugged (don't ask me how I know LOL) it in backwards...Or do you have the new ping which has the voltage regulator built in?


As with Richard - did you look at the product page and click on the Getting Started to verify the wiring? The product page is Ultrasonic Distance Sensor

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United Kingdom

I did look at the getting started for the ultrasonic sensor and I also used the forums as well because I think it must be me doing something wrong. The ultrasonic sensor I am using is the old type with 4 wires.

The voltage regulator came all ready attached to the wires of the ultrasonic sensor so I plugged it in to the right ports when I first wanted to use it.

However, after it didn't work, I looked on the forums and found that the voltage regulator might be the wrong way around. I swapped it around and now it says Vout to the ultrasonic sensor and Vin to the ez robot. I'm not sure if I broke it by swapping it around or if it was always meant to be like that.