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View Full Version : Interferrence between multiple ultrasonic sensors?



Stobs
12-18-2010, 01:24 PM
I've seen a number of bots with multiple ultrasonic sensors and I'm wondering how they are kept from interferring with one another? I looked over a Ping))) pdf (http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/28015-PING-v1.6.pdf)from another thread, but I don't see a way have altering frequencies or some other setting for the use of concurrent use of multiple installations of the same sensor type.

Paul

lnxfergy
12-18-2010, 01:26 PM
You have to wait for this first sensor ping to die out before a second sensor takes a reading. Typically, this is listed at 50-65ms. Thus, a sonar ring is typically limited to ~20hz update rate. (You can often fire 2 sensors on opposite sides of the robot at the same time without a problem, so if you have 4 sensors located on the front/back/sides, you can get ~8-10 readings from each sensor per second).

-Fergs

Stobs
12-18-2010, 01:57 PM
Thanks for your reply Fergs, very much appreciated :)

I didn't mention it but yes, I understood about dissimilar orientation of multiple sensors. Sequencing multiple sensors (of differing scope/sensitivity for my interests), makes a lot of sense.

Paul