interference ultrasonic-censor

[Lars]

Hi
I’m trying to build a ball finder that can find a ball on a board with a border. My problem is that I have a lot of interference between the two censors. I’m using NXT, and the idea is to measure the distance between the top and the bottom censors distance to the objects. If there is a distance gather than four centimeters equals the ball is in sight. The robots slowly rotates while scans for the ball. When ball is in sight at true logic signal is send.
My question is if there is a way to filter out the interference so I get more accurate readings.

sketch:
-------------------------- []
(ball)------------- []

[mattallen37]

So, you are seeing interference between two ultrasonic sensors? I assume you are talking about the Lego ultrasonic sensors. You can use them in single shot mode. In this mode, you choose when they will be sending sounds, so there is no interference between them.

What programming language are you using? I haven't ever tried it with NXT-G, but I know it is possible with NXC, and should be equally possible with ROBOTC or lejos.

[Lars]

hmmm. I am using NXT-G.
I'm very new to the mindstorm, and the NXT-G seemed easy to work with, and I was not awere of the limitations.

Is there a way to turn the censor on and off (NXT-G), or does the censor detects (sending ultrasound) as long as the hole programs run or only when the sequence where the censor is used.

[Lars]

I'm using NXT-G
does the sensor always detekt or only when the sequence where the sensor i used.

[mattallen37]

NXT-G is indeed very limited. There are many many things it doesn't suppot, that NXC does support.

You would need to understand I2C communications, and use the I2C read and write blocks to use it in single-shot mode with NXT-G. I don't program much at all in NXT-G, and I don't know that I could be of much help in the matter.

BTW, the Mindsensors forums are specifically for Mindsensors products. If you have questions about NXT (or any other mindstorms) in general, you should use another forum. Mindboards has an awesome forum (in which I am active). There are many, very knowledgeable, active people there that should be able to answer almost any questions (Software, hardware, electrical...).