Journal2001June
From Simreal
Contents |
June 2001
Yup, I'm an idiot. Or at least, embarassing to myself.
The ICP Programmer, of which I've sold a fair number of PC Boards for, has three terrible flaws in the circuit board.
First, the power plug is wired wrong. That's easily fixed by a jumper, as documented in the instructions.
Then, when transfering the design from rat's nest to PCB, I laid out the wrong width IC. Man, that one really hurt, since I didn't go from rat's nest to prototype to product. I got cocky and went sraight to product -- and expensive transistion, I'll tell you.
Finally, somehow, the VCC and Gnd on the main chip got left out. How, I don't know, because Eagle (my software) is supposed to manage these things! But what really hurts is that, though I documented this problem and it's fix, I forgot to put the repair instructions online!
The first stack of boards I sold, I pre-patched everything. But that got old fast, so I reverted to selling bare boards. Without the patch instructions, how did anyone get it to work? By noticing the flaw, cursing at me under their breath, and fixing it.
But nobody told me it was screwed up! I suppose I should have noticed myself, but you see, my hamster's been sick, and the recent floods in Houston have been distracting, and, um, okay, I don't have an excuse.
Time for my thirty lashes with a wet noodle, and to get back on with life I suppose.
Sorry, guys, for my oversight.
A Brief Diatribe.
I hate prototyping boards. No, not the wonderful Global Specialties solder-free prototyping boards. I hate those little single-sided monstrosities that you buy to translate your push-pin rat's nest into a semi-permanent device. I suppose they are also called project boards. Whatever.
Why do I hate them? They suck!
I don't always want to make a PC board for my one-off projects. It costs too much, no matter how nice they are. Sometimes, when I'm building an interface board, or testing a concept, I want to solder it all together but don't want the expense of a custom circuit board.
That is when I jaunt down to my corner store and pick up a two-pack of those little universal copper-clad prototyping boards. Usually just the little 2" by 3" cuties. Just enough room for a couple of DIPs, some discretes, and wires tangling off the edge onto some connectors.
I use them, because I have little choice in the matter. It's a hate-hate relationship.
You may have used them yourself, so you'll understand. Soon, someday, maybe, I'll make a stack of custom boards so I don't have to suffer so.
First, these crummy little boards are single-sided. That's fine, except that the holes aren't plated through. Soldering a little wire into a giant, unplated hole requires huge globs of solder to make it stick. I like my wire to be in the center of a tidy little volcano of silver; but on these boards it's usually a teetering mass of lead wavering dangerously close to the blob next door.
Of course, all of this trying to get a nice blob of solder on the wire means I'm overheating the pad -- which then delaminates.
Not that the copper is held down that well to begin with. More than once I've traced a problem with an interface board to a point where my external wires have broken the copper pad off of the board, severing its relationship with the neighboring pad. Now I take the pre-emptive meausure of zip-tying all of my off-board wires to one of the corner holes, to relieve stress on the pads.
Finally, each of these boards is laid out on a rigid 0.1" matrix. Again, fine, except that I am then hanging some DB-9 or RJ-11 connector off of the board with a tangle of wires, like an octopus caught in a fish net.
Yup, hate 'em.
So, what am I going to do about it? Glad you asked...
I'm going to (eventually, maybe after this book) create a custom line of prototyping boards.
I'll keep them cheap -- after all, they are for temporary projects. But they will have plated holes.
Yup. Imagine the luxury of this!
Also, along one edge will be a row of staggered holes, just right for dropping in that DB-9 or RJ-11 socket.
They will come in a range of sizes, with shapes and holes suitable for putting into my favorite plastic boxes (which, today, are from Hammond Manufacturing).
Remember, you read it here first.
