Junkbot

Junkbot, aka 'The Rover Mediocrity'

Junkbot is a cratebot, made of almost all junk.




This is the simplest autonomous robot

that is also wireless...




  • Two headlight motors, from the junkyard.. From a nissan, I think.
  • Old 486 laptop, running linux.
  • Wireless card
  • Scooter battery
  • Toyota horn
  • Car alarm
  • Car PA
  • Windshield washer pump with pen tip nozzle, to squirt people.
  • Some custom electronics to connect it all
  • Oh yeah, an old quickcam too but it sucks.



    Junkbot is pretty fun, was really just built to test out my control hardware but it's become a real crowd pleaser. You can just ssh into the linux box and drive it around. I have run it as autonomous, using simple perl scripts but I haven't done anything really elaborate yet since I'm mostly concentrating on the control circuits.

    The milkcrate is the simplest chassis you can do! Just put the motors on the sides, mount wheels on the motor shafts (which is technically incorrect but whatever) put a caster on the back, and then just put the electronics, battery, and laptop in the crate. Presto, robot!

    The idea is that I can put my prototype circuits on the junkbot to test them out. My next step will be to add position feedback from the motor shafts. This will allow very fine control from the software. My goal is to do something similar to turtle graphics and draw on the ground with either paint or chalk. I'm also considering an arm for the top with three-axis control which can hold and trigger a spraycan.

    The best thing though is the motor controllers. They're high-current mosfet H-bridges. They are controlled by two logic lines, for four modes. They have forward, backward, brake, and coast (off). This is the great 'missing part' that has always held back my robot development over the years. Now I have designed it and tested it on the junkbot. It is time-consuming to build, but I'm at the point now where I can build a bunch of them in advance and just take them off the shelf as I build stuff. This has changed everything. I hope to sell them as kits some day, they are just fantastic, and the industrial versions sell for hundreds of dollars each.

    Junkbot is currently crusing around the playshop at the Yerba Buena Center for the Arts, disguised as a lemon tree...