I’m re-inspired to work on this “Slingatron” toy.
As previously mentioned, the CC3200 got its JTAG connection damaged because I got excited and plugged in the battery before isolating the usb power. Now I’m working with the TM4C123GXL launchpad from TI.
Why the TM4C123GXL? Mostly because it has a similar core to the CC3200, I had one and I had yet to ever do anything with it. It doesn’t have wi-fi or an accelerometer on it, but I can add those later if I want. Feature creep is already a problem.
When my initial design was going, it didn’t want to move much. I think I got lucky when it did work. A more powerful motor would probably do the trick, but I saw a way of getting the platform to oscillate that I’m going to explore instead. Here’s the idea:
Why not just copy someone else’s plans? It’s not like I came up with the idea of a “Slingatron” to start with. Basically, I don’t want to, it’s not as fun. This is an exercise for myself. I’m sure that this is not original by any means but I will create it. I looked through my mechanical movement visual reference book (thanks for buying me that Caroline, it’s very cool) but didn’t see what I wanted right away. It could be in there, there’s a lot of terminology that I don’t know and a lot of examples. Instead, I saw the holes on the robot chassis I’m using as a surface and the above design clicked in my head.
I was busy the rest of the night [after work] hacking it together and it seems like it’s going to give the motion I’m looking for. I’m sure I’ll iterate through the design a few more times. May even design and print some more parts. I am trying to balance this with the actual code. It’s the little bits that get ya. I can make the thing move, but wouldn’t it be nice if I had some control? Where do I draw the line between making it spin and making it user friendly? I guess that’s why projects have goals and milestones. I should have started with that. Never too late, he I go:
“Spinatron” type BB launcher project Project Goals:
The code will be “bare-metal” [no OS] and be interrupt driven.
It will be written in C and developed using IAR Embedded Workbench for ARM 7.40.3.
It will make use of existing API for the embedded peripheral functions.
- Using those should keep the code size down because those functions don’t reside in the accessible FLASH. Not that I expect to use much code space in the first place (famous last words?). It should also be more portable to other, similar, TI devices.
I will try to be consistent with naming conventions and use known best practices while maintaining my style.
- While this is a personal project, there’s no reason to not design the code in such a way that it is not a chore to understand or reuse. That being said, I shouldn’t have to be so strict with convention that it’s not fun.
I am responsible for the project.
- That doesn’t mean I won’t use open examples to build upon, it means that if the code, hardware or something else fails, it is my fault. That’s what I believe it means to be an Engineer of any sort. The buck stops here.
There will be a start button, stop button, and analog speed control.
“Good Enough” is okay for this project.
- “Good Enough” means I’m not going to worry too much about precision and vibrations. The goal is to make it work, not to be anything more than a proof of concept. So I’ll try and get the build done in an evening once I get to that part.
- I worry a lot. About everything. Well, except for very special circumstances; that’s how I know it’s a special circumstance. I originally started this project because I saw a picture of a “Slingatron” and knew right away how to design the spiral for my 3D printer. That was fun. I decided to move beyond the 3D print to making it actually function; in hopes of impressing some folks I want to impress. That was a mistake. Things got rushed and I didn’t have much to show myself with. I don’t know if I’ll ever hear back from those folks, but now, I want to make this for me. That means don’t rush, be confident and have fun pulling my hair if it comes to that. I Make best when I make me into it, so do that.
Something I’ve learned by doing:
- the spiral tube I printed has split back into its original halves. As it turns out, nylon and super-glue are not the best of friends. Nylon is pretty cool stuff, being able to print things out of it is pretty awesome as well. To paraphrase a friend, “it’s one of the earliest plastics and yet they got so much right with it”
We’ll see where this goes…