Hi, I have a 26 led POV display that spins at ~2000-2500 rpm. I have 74hc595n shift registers, but it looks like it'll be easier to use 1 max7219 to control the leds. Is this chip fast enough? All i've found are basically matrix tutorials, does anyone have a link to controlling independent leds?
All i've found are basically matrix tutorials, does anyone have a link to controlling independent leds?
That chip is a driver for a matrix, the only way to appear to control individual LEDs is to wire them up as a matrix but physically place them where you want.
yea, that's what I was worried about.
but assuming this thing is doing 2500 rpm, thats about 41 rotations per second. its pretty fast.
if I break the circle up into, well, how about 200 "positions" per rotation, that means the leds would need to be switched on and off in about 121 microseconds.
I have NO idea what the speed of this thing is. 41 rps is overkill so I could do it every other rotation or so, but assuming I don't, is the whole system fast enough?
The arduino-max7219 and the max's ability to switch on and off... what do you think?
The 7219 has a fixed multiplex rate of about 800 times a second, this is 1.25 mS.
You would need to synchronize this rate to the rotation of your wheel to get a POV system. However this is fixed so you can't use this chip for this application.
The other way would be to update the whole matrix at a rate of 41 Hz but I don't think that is on either.