Super Awesome Sylvia builds the ambitious Mousey the Junkbot project by our very own Gareth Branwyn from MAKE v02
Ever wanted a pet but your parents wouldn’t let you? Why not try Mousey the Junkbot! Today we’ll be highlighting the build for this little light seeking bot, from spare parts and an old computer mouse. Lets go! Full details after the jump.
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For this zippy build, we’ll need:
- Mousey the Junkbot kit from Solarbotics or find the parts listed in the article
- Download the free PDF article, pick up MAKE v02 from Maker Shed, or check out this Instructable by m_jake.
- An old ball-type mouse
- 9 volt battery
- Some wire (22 gauge solid core or stranded)
- Some tape or rubber bands for tires
- Old credit card or springy recycled plastic for the whisker
- Superglue, epoxy or hot glue
- And some various tools (see the article for a full list)
First take your mouse and open it up. Before doing anything else, look at the inside of the case. It has to be big enough for battery, relay, motors, wires and sensors. If it looks like your mouse is a good fit, make room for it’s new brains by removing the board and cutting out all the plastic bits, but don’t forget to wear eye protection. Safety first!
Line up where your motors will go according to the instructions, carefully cut out the body holes, then glue the motors in. To make tires for Mousey, you can simply glue a rubber band around the motor shaft. If you want to be super awesome, you can take the pulley wheels from an old audio cassette, super gluing a piece of rubber band around it for traction, then attaching these to the motor shafts with glue (they won’t fit on their own). Once that’s done, you can install the tail switch, and then the whisker switch.
De-solder the good parts off of the mouse’s controller board, then solder the two infrared LEDs to twisted wire strands (preferably solid core to allow them to be bent and moved as needed). These LEDs are run in reverse-bias mode in our circuit, allowing them to measure light and become our little junkbot’s eyes!
Now to build out Mousey’s brain on a breadboard to make sure all our parts work. As with any circuit, make sure and spot check all your connections and components before applying power. Your transistor or opamp can be ruined if not properly wired up.
Once all your circuits check out, assemble them “freeform”, one to the other, inside the mouse body according to the directions. Now that you’re all wired up, be sure and double check your circuit is correctly wired and that all your joints have continuity. If you’re happy with the results, make sure exposed wires are tucked away to avoid short circuits, then carefully pop on the top.
Once it’s together, you can decorate it! We took the two buttons from another computer mouse to make the ears and used some googley eyes and black marker for decorations.
Assuming Mousey is in good shape, it’s time to go experiment! If he’s hooked up right, your little bot will seek out and find the brightest light in a room. Have him skirt around the floor, chase a flashlight around, or try putting him in dark room with a single light and see if he finds his way over to it, it’s so much fun!
One of the best things about Mousey is that he’s a freeform bot made from spare parts. With a little work there’s lots of ways to make him better, and with even less work you can tweak his behavior in fun ways. Try bending his eye stalks or reversing his eye connections to make him seek darkness, or get some bigger wheels and geared motors for more traction.
That’s all we could fit into this episode, remember to experiment, keep trying if something fails, and get out there and make something!
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