Shocking!

The control software is done, save for testing with the actual hardware. Now, the hardware schematic, the plan from which I'll actually wire the hardware together, is also done. I've got to feed it to a circuit board layout tool, then I'm going to teach myself to etch PCBs -- the usually-green base material of a circuit board -- to make the thing and solder it together. Click the little picture on the right to see the full-size schematic (especially if you can read schematics and want to tell me, "Hey, stupid, that won't work because..."). Yes, I realize it's ugly; I'm teaching myself many new skills lately, like "using schematic CAD software."

Two steps forward..

One step back. Sigh. I misread the spec sheet for the motor driver chips, so the capacitors I got the other day are the wrong rating, by a full order of magnitude. Gonna check Radio Shack and see if they have the right rating in the morning; otherwise, it's another week wait or so to get the correct caps from an electronics supply house (and paying several times more for shipping than the capacitors themselves cost).

Additionally, the drill bit I need to continue making progress on the mechanical side bent tonight, so I'm stymied until I can get new caps and the right bit. /grump

The other reason

One reason I created this space is to chronicle the stuff I'm working on, the "what" and "how," if you will, of many of my projects, even if only briefly (like the lamp). The other reason, and equally as important, is to talk about the "why" and the "what does it mean." Sometimes, those two questions are answered with nothing more than "Because it was cool" and "Not a damn thing."

Other times, however, it's pretty profound. Skynet, for example, is something that has some serious implications, if you stop to think about it. I'm going to be talking about that, and related topics, in parallel with the build log part of this space. Hint: what does my autonomous Nerf gun have to do with the future of asymmetric warfare?

Been a little busy this weekend

But for all that, I made some progress. Nothing worth pitchers, but I've got Processing working on the Ubuntu laptop I'm intending to eventually use as Skynet's brain. Arduino is a different story, but that's OK: I can write and upload those scripts on another machine, and just have the board talk to the Ubuntu machine.

Also, the capacitors I need for ground-coupling the motor driver chips arrived on Friday, and I picked up the infrared emitter/detector pair I need for the barrel sensor, so within the next day or two I should have the complete electronics setup done and tested. Then, it'll just be getting the physical structures assembled.

As promised

A picture of the (mostly-complete) lower portion of the turret assembly. I still need to center the motor up properly so it will spin freely, and thread the shaft further so it can be securely attached to the base, which requires a die I don't have immediately available, so I'll scrounge around at work to see if we've got one. I'll most likely have to thread the other motor's shaft further, too, so if we don't have one at work, I'll probably just pick up a tap and die set to do it properly.

I also managed to salvage a five-or-so year old laptop that I had laying around the house that wasn't working properly by replacing the OS with Ubuntu Linux; that's probably going to end up as Skynet's brain, presuming it keeps working with the Ubuntu install.

And now for something...

Completely different. An unrelated, decorative lamp project, first of several I've been tossing around in my noggin. The basic idea for this one was shamelessly stolen from The Steampunk Home; one of the others is an aggregate of several others drawn from the pages therein.

Skynet is progressing nicely. I've figured out a way to test the interrupt handler I thought was going to go untested until the rest of the hardware was more or less together. The base of the turret is partly complete, with the swivel bolted down and ready to go, but I have the wrong size screws to attach the mount to the swivel point and get the x-axis motor rigged to both. Once those two things are set, I'll post a pic of the assembled base, probably tomorrow.

Initial code testing complete

I rigged up a breadboard circuit to test the microcontroller code and the terminal software as well. It's ugly, but it permits two-way communications between the laptop and the Arduino. Moreover, it lets me see that it's getting the right physical signals, by lighting up LEDs for the left/right/up/down and trigger commands, and including a button for resetting the ammo count after reloading.

On a related note, interrupt handlers are evil. One of them I won't be able to test properly until I have the actual rig assembled; the "did I fire?" jam check is done with a photodiode interrupt circuit. It's pretty time-sensitive the way the code is written, so it'll have to wait until the machine is more or less rigged up to test that routine properly. Jam detection is just a nice thing to have right now, anyway, not a critical issue.