End of an Era
I’ve been having a lot of fun playing around with different technologies. I enjoyed unguided dabbling in realms all the way from the battery to the web-based UI. It is thus, with reservation, time to acknowledge that I must move on.
What do I really want to do? I thought it was build a robot. I did that many times. I was wrong. I want to be able to more robots, quicker and cheaper than I do now. I also want it possible for anyone with a 3D printer to build.
Skills Necessary to Pay Robot Bills
I want one of these robots to be able to be built by any random kid. I got my first soldering iron around 12 years old, so I’m going to shoot for that level. However, I would not expect the kid to be able to do much more than assemble it. For programming it with new behaviors, I’d expect that’d take to around 15-16 years old. Once again, that’s when I started getting more comfortable with programming small projects.
As for tools and materials, here’s an abridged list:
- 3D printer
- Linux computer w/ a nice screen, keyboard, and mouse
- Screwdriver (assorted or a kit)
- Pliers, tweezers, etc.
- Calipers (digital and semi-accurate)
- Battery charger
- Lots of unguided free time, like I did
The rest is consumable goods and other parts.
Building Robots with a Grain of Salt
While not all parts are known yet, here’s an overview of the constituents.
- PI compatible NoIR camera — Night vision is important, as pets with dark fur could otherwise evade detection.
- Range finders × 8 — We got the IO ports on the Micro, why not use them? I like Pololu’s Sharp analog distance sensors. They work well, have a flat beam that makes it possible to mount at or near the same level of the wheels.
- Stepper motors × 3 — I started off with NEMA 17s with a good amount of torque. My suspicions are that I can drop to NEMA 14s, and with the reduced weight not need as much torque.
- Omnidirectional wheels × 3 — I swear by the Vex IQ 63mm omni wheels. They’re affordable and easy to make a custom hub to attach to any motor.
- Stepper motor drivers × 3 — I’m a fan of Pololu’s DRV8834 driver. It allows me to use the same power rail for the drivers and Arduino, which are on the same board. A few beefy capacitors in key spots, and it seems to work rather well.
- IR illuminator — One of the circular ones designed for outdoors works well. Usually you can poke the PI cameras right through the center.
- 7.2V battery — I got a Rage RC 5000mAh NiMH battery. It does the trick. This is only the second battery I’ve needed to buy in years, so I have little experience with these other than: they work.
Godspeed You! Robot Emperor
With these goals and ideas in mind, off I go to design what I hope is a robot so cool, it will inspire people. Failing that, it will terrorize my cats. I can live with either outcome.