how to compare two analog signals ?

markallen

Hi, I have two contact mikes attached to my ping pong table, and I'm trying to get my stamp to tell when the ball hits the left side or the right side of the table. I've attached the mikes to a 386 op amp and have amplified the signals enough for the stamp to read them as an on/off signal. But, when the ball hits near the middle, both mikes register the signal. I'm looking for a way to check for two conditions...

1) is there a signal of high enough amplitude to indicate a hit?
2) if there is one than one signal (left and right side of table), which is higher amplitude?

any advice? I'm also interested if people have other ideas for detecting where the ball hits the table.

thanks!

Mark

Beau Schwabe

Can you post any schematics of what your current setup is? That would help.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

metron9

I would think putting the mic's back to back and placeing them dead center of the table under the net, The bounce noise would then be higher on one mic than the other no mattar where the ball hit. All you are looking for is a higher signal on one mic vs the other that should do it.

You may need 4 mic's back to back one set on each side of the table, with that setup you could detect the left or right side of the table vs the middle section to some degree as well.



_________________________________>mic1{net}mic2<____Boing_________________________________

Mic on right would regester higher than mic on left the > and < denote the direction of the mic facing, perhaps a horn to amplify the noise and shield the noise from the other mic as well?

Post Edited (metron9) : 11/11/2005 7:13:14 PM GMT