Why such a question, could you tell me the led driver, which can control 24 channels (and adjust the brightness, PWM). Availability of libraries for this driver in C for Atmega16/32. Perhaps, of the mandatory requirements — accessibility and popularity.
TI: TLC5947, TLC5951, TLC5952 — small packaging
NXP: PCU9656 etc
ON Semi: CAT4016-like.
at Maxim, too, the range is
and I lot of things
The large manufacturers have their own line, so the directory on the local store to hand over :) by the Way, do not bother 24 channels especially. Most drivers communicate by protocols such as I2C, so take 3х8 (one per channel) may be easier from the point of view of wiring and image processing.