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Topic: car parking using Ultrasonic Module HC-SR04 Distance Sensor For Arduino (Read 2 times) previous topic - next topic

fou2

The specs claim this ultrasound is 40kHz.

I've tried putting drops of water on the transducer element and at that point it just stopped working (gave me a 0 cm response). Now going from transducer to air to water to air might not be a good idea as the interface between each medium would give a pretty strong reflection with little energy going through.

I guess there are two directions I can go at this:
1- test by nearly submerging the ultrasound elements in hotglue so that the sound wouldnt have an interface when coming out and would go straight to the outside world --> this will permanently mess it up if it doesnt work

2- place the transducers deeper in the bumper so that they are more protected from rain and maybe put them in a tube to protect them from most rain direction

still no response from manufacturer

teckel


The specs claim this ultrasound is 40kHz.

I've tried putting drops of water on the transducer element and at that point it just stopped working (gave me a 0 cm response). Now going from transducer to air to water to air might not be a good idea as the interface between each medium would give a pretty strong reflection with little energy going through.

I guess there are two directions I can go at this:
1- test by nearly submerging the ultrasound elements in hotglue so that the sound wouldnt have an interface when coming out and would go straight to the outside world --> this will permanently mess it up if it doesnt work

2- place the transducers deeper in the bumper so that they are more protected from rain and maybe put them in a tube to protect them from most rain direction

still no response from manufacturer


You should probably just use sensors designed for car bumpers as they won't be damaged by water.  You'll need to make sure you get a control circuit too as just sensors won't do anything on their own without the proper circuit and script.

Tim
Arduino - Teensy - Raspberry Pi
My libraries: NewPing - LCDBitmap - toneAC - NewTone - TimerFreeTone

fou2

A quick google search showed
http://www.sportsimportsltd.com/parking-sensor-kit-with-display-buzzer-and-4-sensors.html
which seems to be decently priced at 99$ for 4 sensors and a display.

Was hoping to do it with really inexpensive ultrasonic sensors as bought on amazon for 6$ each (but then, LCD is 20, arduino is 30 and they wont be as reliable).

fou2

Additional observation: the ultrasonic ranger was giving me 0 reading half the time. After sprinkling water and cleaning it off, the sensors seems to be giving reliable measurements more than 90% of the time. Perhaps it was dirty or something.

GoForSmoke

Out behind a car when there's wet, dirt, and spray, pretty much everything gets plated over time.

Maybe have an enclosure with a sealed hatch that opens/closes itself?

LCD for feedback is a bad idea. The driver would watch that instead of looking behind!
Use audio cues instead. Faster beeps when closer, slower when farther geiger counter kind of thing.

And for sure, get at least one other kind of sensor. A PIR picks up body heat, would see animals and people that ultrasound might miss. Don't make a tool that will inspire false confidence when you might get blamed for the consequences, not when there's cars and people involved. CYA.

I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

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