The basic idea is I want to hook one of these up to a bike and track the proximity of incoming cars while riding on the side of the road.

Basically I'm trying to expand on the idea of the backup sensors that you can find on cars today except at a longer range (around 30ft) so at 30 ft you would hear a beep and as the object moved closer the beeps would increase. I feel like you all should know what i'm talking about. So basically I am just trying to improve range on an already developed idea.

so are you suggesting using a laser sensor? I would be detecting large objects around the size of a car.

I'm trying to build a device that can measure long distances(around 60 feet) I've considered sonar but am wondering if there are any better alternatives. Any suggestions?

Fiddled around with it a little more I was getting a read of 269in and 0in and the serial monitor was changing between those two numbers. I have since fiddled with it some more and I am not getting a straight read of 270in waving my hand over the transducers does not change the distance. Any ideas?

Ok so I got the transmitter working( I can hear it clicking) however I can't seem to receive a signal. I built this rangefinder based on raron's which can be observed here -->

http://s557.photobucket.com/albums/ss11/rar0n/Electronics/Arduino/?action=view&current=Ultrasonicsensor1.png
as well as the breadboard here -->
http://s557.photobucket.com/albums/ss11/rar0n/Electronics/Arduino/ultrasonic/?action=view&current=IMGP6404.jpg

Anyone have any idea why I am not able to receive a signal? I'm pretty damn sure I built it the exact same way.

I came across this schematic and I was thinking I could model it ---> http://www.micro-examples.com/public/microex-navig/doc/090-ultrasonic-ranger.html

however I am unclear on what one part of the circuit is.

The part of the schematic in question is the area to the right of R1 and below D1 (the red with the arrow pointing down and to the right)

Thanks for all the help!

I just noticed that the images in the old forum for that post don't come up properly (they're too tiny to read) - here is raron's user profile on here:

http://arduino.cc/forum/index.php?action=profile;u=11873

He seems like he is still active - so maybe he might post up something; if not, I'm pretty sure I snagged a copy of that thread and the large images, maybe I can repost them somewhere...

awesome. that looks like it will help a lot. Thanks

any ideas about what I need to get these particular ultrasonic sensors to work? I already bought them so I might as well use them. I read somewhere that I could use an LM833 as an amplifier and a MAX232 to provide a larger voltage to the sensors in a circuit similar to this one: http://www.robot-electronics.co.uk/htm/srf04tech.htm however is there anything else that I would need on top of that to make this work?

How big is the "moving object"?

Lets say the size of a car.

Well the basic idea for the thing i am trying to build is to keep track of the distance a moving object is from the point of origin. From approx 18m to lets say around 3m

Ok, i'll look into that. The reason I chose those sensors is because of the range approx. 18m where as the Devantech SRF04 only has a range of approx. 3m. I figured I would just get those sensors and build around them.

Can you be more specific? I am very new to programming and working with the arduino. It is my understanding that I need to feed 40khz into one, then amplify the other and listen for a reply(they came in a pack of 2). I am not quite sure how to make this happen though.
Thanks.

Hey all,

I recently ordered a set of long range ultrasonic transducers from here: http://www.futurlec.com/Ultrasonic_Sensors.shtml
I was wondering if anyone can offer any advice on how I can hook these up to start reading distances.
Thanks in advance