smeezekitty:
Hippynerd:
showing some tests is one way, but calling it a crap design by someone that doesnt understand what they are doing is totally subjective, thats just your feelings, not the truth.The truth seems to be that you may reduce the lifespan of some or all of the parts. If you dont protect your LEDs with resistors or some form of current limiting device, they will probably fail sooner than if you had.
Why willingly reduce the lifespan of components if it could easily and cheaply avoided?
It makes absolutely no sense to me. Datasheets do not lie. There is reason they are only rated at 20-40ma.
it doesnt have make sense to you, thats ok. If someone asked you to build 100 fixtures, that only need to work for 3 days, then never again, and the money for the parts was coming out of you pocket would it make sense?
It isnt really up to you or me, its up to each individual what they want to do, and under some curcumstances that you may never have considered that it could be useful. Like when its not cheaply or easily avoided.
Myownway:
You could use a transistor on common anodes, and resistors on the cathodes.
Fungus, how is building something that someone else designed and built dumb luck. I have repeated the test 3 time, and had the exact same results, its not dumb luck that these cubes havnt failed.
You have convinced me only that you are angry, and want to call me names, that is not a reflection of me, that is your business. I wont resort to calling you names, because that isnt helpful, its counter productive, and just mean.
My being able to do something that you can not do, does not make me an idiot, it just makes you mean. If you want to get on your high horse, and talk about whats bad, then lets talk about calling people names, and justifying other people calling names, is that good or bad fungus?
Mike, I dont remember anything about perceived brightness, it looked to me he was doing a duty cycle calculation. The code in the original post lists mentions a variable called brightness, but I dont see anything about perceived brightness. Myownway does ask "I wonder that this may be related to joule/second = w, but I'm not sure."
I do like the expression differently correct, but I dont see that as appropriate either. "It will work, but it will likely fail sooner than if you use resistors or other current limiting device." states all the important information, without injecting feelings.
Crossroads:
Yes, the rework can be quite difficult in a cube, i've had to replace a couple LEDs in my first cube, and it was pretty difficult, even on a small single color cube. The I have repaired a few spires from this charlieplexed cube, and its actually a lot easier than a single color cube. I think its the lack of gridded wires that makes it easier to get into the LEDs on the spires. Have you looked at any of the pictures that took? Its is way easier to repair a spire before you solder it onto a board, but if one LED is messed up, its not too hard to replace.
boffin: Im glad you like it, you can use it if you like, i dont own any rights to anything, and I really dont care either way.