Max Arduino Uno Ultrasonic Sensors

I'm looking for some information on Arduino and UltraSonic Sensors. I'm considering getting the following Arduino Uno board (http://www.sparkfun.com/products/9950) for templating the basics of an installation piece.

I'm getting started with this and wondering if anyone could tell me what the maximum amount of sensors (http://www.robotgear.com.au/Product.aspx/Details/285) it would be able to connect at any one time?

Many thanks,
ant.

http://robot-electronics.co.uk/htm/srf02techI2C.htm

You can set the I2C address of the module to any one of 16 choices. That means that "up to 16 sonar's can be used" on a single I2C bus such as is found on the Arduino.

Thank you so much for the reply, it's very helpful!

We would also like to add an LED to each sensor to show which sensor we'd be currently reading from (imagine them spread around the face of a clock and reading each sensor clockwise).

I'm guessing if we're maxed out on 16 the best route would be to run a second board to handle the LED's and sync them up?

ant.

Don't forget you might have interferences between your ultrasonic sensors. One burst of impulses from one any sensor may be caught by the others. To avoid problems you should synchronize the sensors.

antonmills:
I'm guessing if we're maxed out on 16 the best route would be to run a second board to handle the LED's and sync them up?

The I2C bus only uses two pins (A4 and A5). You still have about 17 pins for other stuff. With 8 pins you can make a 4x4 matrix display of your 16 LEDs.

Awesome,
I think the concept is to iterate through the 16 sensors (all facing in different directions) linearly at set intervals so it may be a bit of trial and error to find the correct intervals to not get any false reads.

@johnwasser thanks so much for the heads up on the extra pin usage for the LED's, most helpful.

Cheers all, I'm looking forward to getting in to building this :]

ant.