Help design Ultrasonic sensor

[Pravi]

Hi,

I have purchased an Ultrasonic Transmitter and Ultrasonic Receiver, but not sure on the design (how to put them together in a circuit and make them working).
I tried searching the forum for Ultrasonic transeiver, but could not find the schematics for that.

Can someone point me, or give a link for Ultrasonic Transeiver schematic and design details?

[SpaleKG]

Can you give more info about your devices. You should receive some user manual. Or simply give label and manufacturer URL if you have.
When we know what is inside your device, then we can help you.

[solutions]

http://www.robot-electronics.co.uk/files/srf1.pdf

http://www.robot-electronics.co.uk/htm/srf04tech.htm

source code: http://www.robot-electronics.co.uk/files/srf1.asm

[Pravi]

This is a perfect solution except that they have used PIC and assembly where I was looking for AVR and C. Well, that shouldn't be difficult to port it to AVR. If I succeed, will share the project here. Thanks for the solution.

[th_sak]

Here is another DIY project which uses ARDUINO. Firmware can be easily adapted for any AVR controller. If you know how to program AVRs then you probably know how to load the ARDUINO bootloader to your AVR and run this firmware as is.

http://www.kerrywong.com/2011/01/22/a-sensitive-diy-ultrasonic-range-sensor/

[Ahmed106]

Hi, You can have a look at this DIY Ultrasonic range finder project it could be helpful
http://www.micro-examples.com/public/microex-navig/doc/090-ultrasonic-ranger/

Regards

[Marnic]

Read this:
http://www.murata.com/products/catalog/pdf/s15e.pdf

If you want to improve the sensitivity, study well the scheme of the receiver

[Ahmed106]

@pravi, Can you please post some details of your Ultrasonic Transmitter and Ultrasonic Receiver & Manufacturer Details

[pushycat]

@pravi, Can you please post some details of your Ultrasonic Transmitter and Ultrasonic Receiver & Manufacturer Details

This is usually the toughest thing..coz Indian market is normally flooded with chineese fakes, no one knows the exact origin of a component. Despite the component will be sold by a reputed hobby kit dealer, the exact origin is 99% china. This came to my experience when i tried to assemble a project Ultrasonic distance meter published in EFY magzine and it gave me maximum range of about 90 cms and then it blanked the display beyond that. A week back i happened to assemble the same circuit and the display came on only when i tapped on the RX's body. This meant the Rx side was working. Then i tried to hear something on the Tx side. Usually i hear a hissing noise when tx transmitts which is actually a ultrasonic burst but not audible to human ears. But this time nothing was heard. Then on a guess i replace the Rx and Tx pair from a different source, and the kit worked as before. To debug this, it took a day long of hard work after supecting all the capacitors and componenets etc. So if those sensors can be tested by any standard means, before assembling, we can buy better quality ones and too save our precious time...

@Pravi...A similar project is published in recent EFY magazine and will be put in the "EFY projects"s section of Sonsivri soon.


Pushy

[LabVIEWguru]

Are these small round transducers?
You know the frequency is around 20 - 32 khz. I am thinking that if you use a signal generator and a scope, you could sweep the signal generator on the transmitter and when you have the resonate frequency on the signal generator you will see a sharp drop on the scope. If you go too high in frequency you could also see a odd harmonic I think.

I used to have some articles somewhere. I will see if I can find them.

Here is one to get you started:

go to google books
bibliogroup:"Ciarcia's Circuit Cellar" or search for "Ciarcia's Circuit Cellar"

3rd book down - Volume 5

chapter 15: "An Ultrasonic Ranging System"

This will give you basic information.

Also Volume 3 page 42 is another article.

If you know someone that has an old Polaroid camera many of those had an ultrasonic range finder in them.

[pushycat]

Yes..these are 16mm in diameter with alluminium casing, look like a bigger version of an electret condensor microphone.
Pushy

[Pravi]

I am thinking that if you use a signal generator and a scope, you could sweep the signal generator on the transmitter and when you have the resonate frequency on the signal generator you will see a sharp drop on the scope. If you go too high in frequency you could also see a odd harmonic I think.

Sadly, I do not have Scope. I tried many of the tutorials mentioned above, but with limited time and resources, am still unable to do it. However, I believe that I will do it one day and certainly share it with the world

[Parmin]

Sadly, I do not have Scope.

Then try the microphone input on your computer.
Lateral thinking.

[Sideshow Bob]

Then try the microphone input on your computer.
Lateral thinking.

I do not know how smart that will be. Most sound card to day. Still have a max sample frequency at 44100 Hz. And a bandwidth in the range 20Hz to 20KHz. The bandwidth may be limited both by analog and digital methods. As many sound card use sigma delta types ADC.

[LabVIEWguru]

If you use a 555 with a small transistor to drive the transmitter and monitor the collector current current of the transmitter, I think the current will climb up until you are on resonant frequency of the transmitter, then it will drop sharply. When you are on resonant frequency of the transmitter, if the receiver transducer is in front of the transmitter you will have some small output. If it is enough to see with a voltmeter set on the lowest scale, I do not know.

[Pravi]

If you use a 555 with a small transistor to drive the transmitter and monitor the collector current current of the transmitter, I think the current will climb up until you are on resonant frequency of the transmitter, then it will drop sharply. When you are on resonant frequency of the transmitter, if the receiver transducer is in front of the transmitter you will have some small output. If it is enough to see with a voltmeter set on the lowest scale, I do not know.

I will try using 555 on a breadboard. Does breadboarding the circuit affect the final output? I mean because of the noise caused in the breadboard?

Then try the microphone input on your computer.
Lateral thinking.

I am not sure if this works for Ultrasonic sensors. http://www.zeitnitz.de/Christian/scope_en has a soundcard scope, but not sure if someone has tried this for ultrasonic sensors.

[Sideshow Bob]

http://www.zeitnitz.de/Christian/scope_en has a soundcard scope, but not sure if someone has tried this for ultrasonic sensors.

Sorry I do not think it will work

[Parmin]

Sorry I do not think it will work

Then buy a scope.

[DreamCat]

if you know the theory of the distance mesure use Ultrasonic, you can write the code yourself.

the basic theory is :
sound is a Mechanical wave, wave transmit in air need time, that is speed. when you send a few 40kHz pulse，after a while, you can recieve the reflected wave by your mesuring object.

when you start to transmite the pulse, turn on a timer/counter, when you recieve the reflacted wave, end the timer/counter. So you can get a time on double distance ......

sorry for my bad english....