Controlling hundreds of LEDs

[Neil]

<snip>
I am curious if any of the controllers you know of permit brightness control
by duty cycle (as opposed to voltage) that would have a much wider dynamic
range than just two, like "bright" or "normal" intensities?

The latest such controller I've worked with allows the pilots of Lynx
helicopters to vary the brightness of cockpit displays to cater for ambient
from night (using night vision goggles) to full sunlight.
No big deal. Been around for ages.
One thing that the wonderful frequency stuff seems to ignore is the need to
continually use almost all of the cpu power and write huge amounts of data
to the port. Using latches to store the LED controls allows the cpu to do
something else for 99% of the time. Also reduces interference emitted from
your LED circuit - could be a source of trouble with the neighbours if you
interrupt their tv/radio...
hth
Neil

 

[John Fields]

---
The ratios of frequencies between adjacent notes on the equally
tempered scale is the twelfth root of two. No such relationship
exists between the tones used to generate touch-tone DTMF. Moreover,
the only outputs available from a normal touch-tone keypad are seven ^^^^^
12

two-note chords, so calling what you can get out of a touch-tone
keypad a 'tune' might be stretching it.