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### Author Topic: Robot sound tracking system  (Read 4047 times)

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#### mankmanky1

• Beginner
• Posts: 1
##### Robot sound tracking system
« on: February 19, 2009, 09:06:02 AM »
Hi

I have the following project:

I need to build a robot with 2 microphones attached to it on either side. The robot is placed on a 4x4 meter grid. 2 speakers are placed on the top and left side of the grid respectively. They each output a specific frequency.

I need the robot to establish its coordinates based on the sounds received from the 2 speakers and then move to a specific coordinate...

Any ideas?

Thanks

#### HyperNerd

• Robot Overlord
• Posts: 139
• N3rd1n80r
##### Re: Robot sound tracking system
« Reply #1 on: February 22, 2009, 03:09:43 AM »
Welcome to the forum !

How big are the coordinates, i.e is the grid 10x10, so a grid 'square' is 40cm x 40cm?

You could try and do something with volume measuring with a band pass filter on each microphone set to one of the two frequencies of the speakers; two VERY sensitive voltage sensors, and measure the slight variations in voltage, and therefore volume, as the robot moves further away from the speakers.

I've never tried this before, so this is just off the top of my head

-HyperNerd
There are 10 types of people in the world - those who understand binary, and those who don't.

• Supreme Robot
• Posts: 11,632
##### Re: Robot sound tracking system
« Reply #2 on: March 01, 2009, 07:02:49 AM »
This is actually pretty simple. It's exactly the same as a photovore, but instead of chasing light it chases sound.

here is what you do:
build the \$50 Robot

But instead of using photoresistors, you use microphones. Now the microphone closer to the sound will receive a higher signal amplitude. So you will need to make 'sound level meter' circuit and feed the output to the ADC.

This schematic won't be easy if you know little about electronics, so you'll have to google around a bit until it all makes sense. The left half of this schematic will kinda work, depending on frequency/amplitude:
http://www.aaroncake.net/CIRCUITS/vumeter.asp

Also look around for an 'audio level' IC.