Let's Make Robots!


Navigates via sound (as a contact switch) or IR for obstacle avoidance

A while back, JAX and I got to chatting about our first robots.  Mine was a "Movit Peppy Mouse:"

It was pretty much a red hexagonal piece of acrylic that ran forward until you clapped or the microphone bumped into something, at which point it backed up and a slip wheel caused it to turn to the left (I think) then it when on its merry way forward again.  A while ago one showed up on eBay and ended up going for about U$35.  Anyway, I decided to see if I couldn't recreate it.  This was quite a step down in scale for me-previously the smallest real robot I'd worked on was aRDui5X-who is about 13 inches tall (not counting the D.A.M. and the Spiduino, both of which were just tests for servo that got torn apart as soon as I had video posted here.)  So this was not my Start Here Robot, but rather my Re-start Robot.

Originally, I was going to use an ATTiny 85 running Servo8bit.h.  

That didn't turn out to have the resolution I wanted so I took the 328 I originally had put in the board I made for Serv-O and repurposed it.

Again, it's really a 328 under there.  The sticker is just for a pinout. I tried to keep the board neat, inspired by Dominic's (BlueBeta's) Akira project, but let's face it- that's a pretty high standard. Still, I'm quite happy with my first successfully deployed bench-built Arduino.

For the body, I used Sintra (which is PVC sheeting, essentially what most drain pipes are made our of these days in flattened form.)

Here's another view of him:

The motors are just two DGServo CR servos and the castor it turns out you can get at Harbor Freight if you happen to live near one. I love those battery packs with the built-in power switch-very convenient.

The main video shows how well he works, which is to say, not very.  He may be reacting to when I clap, and it may be the noise transferred from the body or just ADC noice.  He may not be hitting the wall with enough force to trigger the random turn, because as you can see he tries to keep going when he bangs into it.

I considered reprogramming him with a queued sample set to compare the current sound levels to, but frankly I just kind of lost interest.  Partly, that's because the original SparkFun Electret board burnt out half way through a test sketch (and they kindly sent me a replacement immediately)  While I was waiting for it in the mail, I decided to apply the Short-range sharp sensor and convert it to a variation on the SHR.  It works pretty well.

This video is of it using the Sharp sensor:


Maus from Jason Hoffman on Vimeo.


Obviously he looks cooler this way too.  E/D distance sensors always look more like faces (Wall-E's) so they have more personality.  If history is any teacher, I probably will just set him aside on the work table until I see that he has a part that I need and then cannibalise him, but until then, I can consider my first robot remade.  This actually feels pretty good to have done this much of the work myself-Ardui and Servo both use factory Arduinos and shields and Yubin Kun works off of an old Powerbook and Phidgets as interfaces.  I don't know if I really want to go this route again, but at least I proved to myself I could do it.

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very nice