For an amatour robot project, I needed to measure the difference of distances between 2 ultrasonic transducer and one receiver.
We(my and my teammates at that project) bought Ardunio Uno cards and HC-SR04 modules and made some "operation" on modules. We disabled one module's receiver and the other ones' transmitter; then connected both to the same ardunio, measured time difference between transmitted and received sound(no calibration problem on the test due we used the same ardunio for both) and calculated distance by..
However, the case is; the transmitters' transmitting "angle" was too narrow for our usage.
We tried some other paths, but they did not seem to work either(RSSI and we considered Cricket indoor localization), so I though about using whatever we have by different paths.
We were unable to use ultrasonic transcevirs due to angle case. So, I thought using a 40KHZ ultrasonic transmitter which has larger signal "angle" with our half-disabled HC-SR04s.
I am considering buying these http://www.farnell.com/datasheets/1847127.pdf?_ga=1.214659863.1035364629.1469821844 However, they are expensive for myself to buy( and I am unable to get financial help for this test), so I though buying some cheap ones to try first and further testing by these wide-angled ones when we buy them. Cheap ones I am considering to buy https://www.amazon.com/Pairs-Tct40-16r-Ultrasonic-Transducer-Sensor/dp/B00UKONMTM
I was about to buy them and try, but then I noticed that most similar ultrasonic transducers seems to have some minimum working voltages which are numbers with three digits(The one I am thinking to buy works with minimum 15 volts); so I just googled how to use ultrasonic transducers. They seems to need some special circuits with capacitors. For example: http://electronics.stackexchange.com/questions/93458/how-to-wire-up-ultrasonic-transducer http://electronics.stackexchange.com/questions/56/how-do-i-drive-an-ultrasonic-transducer-with-an-arduino
Everything is fine until now. The case is, I am pretty much no means of electronics, so I don't know how can I make these circuits. I cannot just copy these circuits either, I cannot be sure they will work with parts I wanna buy.
I am a mechanical engineering student, first grade. I did not get proper education to work with that electronic parts yet. I made HC-SR04, HC05 worked with Arduino Uno before.
I just need proper basics to build this circuit, any tips would be helpful. Thanks.. :)