An ATTiny2313 powers this night light, driving multicolor LEDs diffused by ping-pong balls. nuumio writes:
Geir’s RGB night light was such an inspiration I just had to make my own. Instead of Picaxes I decided to use ATTiny 2313. At first I tried to program it with C but I ran to some “differences of opinions” with gcc when I tried to assign dedicated registers to variables holding duty cycle values (for speed optimizations). After some struggling I gave up and coded the whole thing in AVR assembly. I was quite surprised how easy it was after all. It took me about one weekend and I got first versions running nicely.
Great job, nuumio!
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Beware of circumventing gcc’s optimization engine. It’s better than you think it is.
Personally, I wouldn’t have jumped over assembly for this. You could simply let the compiler do the optimizations and give it the additional -E flag to tell gcc to output the equivalent assembly code. You could then review the output to determine if going the assembly route was really worth it (probably not, in my experience).