An even cheaper bump sensor?

[cinderblock]

Hello! Love this project. We saw your inexpensive bumper idea and wanted to share how we did exactly this... wow nearly 10 years ago!

The most notable difference is that we didn't use pressure sensors directly. We just used a speaker (or was it a microphone??) at each end of the tube to get good impedance matching. These signals were AC coupled, amplified, and connected as analog inputs to an Arduino. This let us easily detect the amplitude and time of the first detected peaks.

But, we were able to go one step further!

We noticed that the signs of the first peaks of the waveforms from each sensor could rather reliably detect the difference between different directions of glancing bumps! So, we could no only localize and measure amplitude of the bump but also detect the general direction (direct, left to right, or right to left) we got bumped from!

We actually got to go to Willow Garage and strap this bumper to one of their PR2 robots. Everyone was confused why we kept running into walls!

I'm looking for the old code for that system. I think we still have the old hardware collecting dust somewhere. If I find it, I'll pull it out and get some pictures here. We just want to see more people use this fun idea and thought someone here would like to hear it. Cheers!

[ryansusername00]

Sounds pretty cool, would love to see the bumper.