This was actually done a week ago, but a little thing called Mass Effect: Andromeda came along, and I’ve been distracted. I just never got around to writing this. So on the theory that late is better than never, here we go.
This may look like a duplicate post, but it’s actually something different. This is a step that I sometimes skip, but usually like to do if I have the parts. It’s basically a rough build where I can see what mistakes I’m making before I do the “final” build. I look at it as the breadboard prototype is sort of like an outline for a paper that you write. It gives you the basics. The prototype build is sort of a first draft. It is your paper, but it’s nowhere near ready to turn in. And then the final build is the finished product…not to say that it still wouldn’t be further improved and iterated on, but that’s just where the analogy breaks down.
The same basic steps are followed as in the breadboarding prototype that I did earlier, so I’m going to load these pictures in as a gallery, and then talk about the challenges and what I learned.
They’re in the slideshow below. There should actually be more than this, but I kept getting involved in what I was doing, and forgetting to take the pictures! I may start just filming the whole thing, and capturing images from that, or something. Yes, I have one dead LED in the final image.
I was doing this without proper tools…which will be the case when I am doing the final build as well. That’s a big reason that I had to do this intermediate step. First, my cutting wheel on the rotary cutter tends to over-cut. That’s normal on round-blade cutting…just ask anyone who’s ever done a project that requires precision using a Skil saw. It’s still something to get used to, and so the edges are very over-cut in some places. Second, the box is big enough, but it’s going to get some adjusting for internal layout in the next iteration. The charger will probably come out the bottom instead of the side, for instance, which would allow it to lay flatter next to the battery…and would allow the battery to lay flat on the bottom. Turning the potentiometer so that the pins were up and just bending them over was kind of dumb, too. It’ll work better if I put it on it’s side, I think.
Things I Learned:
I suck at freehanding! I actually already knew this, but it’s been a while, so I forgot the depth of my unfortunate inability to draw anything resembling a straight line. This can be a problem when cutting without guides. I’ll probably want to rig up a jig of some sort to help me when I try again. Also, I need to buy some bits. I’m actually thinking that a couple of milling bits might be my best bet, since they cut both vertically into the piece, and sideways across it. Also, it wouldn’t be the gross overcut of a circular blade, or the wobbly result of a cone-shaped cutter. I’m going to need some hot glue or something. I don’t really like using hot glue on these projects, but it does work, and it’s very flexible in that it can be used in a lot of ways. When marking the lines to cut out in the lid based on the PCB, I need to “indent” some on the sides, and not just the top and bottom. I forgot that this time, and with my inability to draw a straight line, I have gaps to either side of the light board. Instead of trying to use standoffs to raise the PowerBoost 1000, I’m thinking of either gluing down standoffs, or just not worrying about them at all. It does get hot, but primarily on top, so minimal bottom air flow isn’t going to help tremendously. I learned that I need to count better, since if you look closely you’ll see that I was short a ground connection, and just soldered the extra wire to the pin on the power switch. It works, but I hate making easy-to-avoid mistakes like that. Layout. I need to do more work on the layout. I think that will make things much easier. Also, on the “final” version, I’m going to cut the wires with much closer-to-ideal lengths, and connect the actual light panel via a plug-able JST connection. Basically, I’ll wire all the parts, place them, and then cut those wires to fit more precisely. And since I’ll be gluing or otherwise actually securing these pieces, then it should all fit together more neatly.
- Project Box
- Adafruit PowerBoost 1000C
- Arduino Pro Micro
- small SPDT switch
- Hookup Wire
- 5cm x 7cm Single-Sided PCB board
- Diffused White LEDs
- Potentiometer (I used a 5k, but that’s just what I grabbed)
- Nylon standoffs
- Helping Hand
- Rotary Tool/Dremel
- Flush-cut wire snips
- Wire Stripper
- Soldering Iron (cheap) or Soldering Iron (good)