Why in parallel?
Do you really need 24 bit color depth?
Do you need the LEDs to be individually colored or can you use a color palette?
Do you really need 24 bit color depth? ... I don't believe there is any other way. Unless I've missed something, the LPD8806 takes 8 bits per channel per LED.
Do you need the LEDs to be individually colored or can you use a color palette? ... I'm not sure what you mean by a color pallet. I believe the LPD8806 takes 24 bits per LED regardless?
Sorry, wasn't clear, because the strips are arranged in a radial pattern, and it would be immensely less work on the setup-front to have them all fed from the center.
(24 bits/(RGB LED) * 32 RGB LEDs/meter * 5 meters)/frame * 30 FPS = 115,200 bps. You have 32 RGB LEDs per meter? ~1/inch, okay, guess that makes sense.Gonna need one big power supply too.Can you increase the interface speed? The IDE will do 250,000. Not sure how efficient your code is to parse the data across the streams.Sounds like 16 MHz 8-bit processor might bea tad underpowered.
Isn't it just a question of running one line from one digital pin to the select pin on each LPD8806? Or are you trying to position one microcontroller close to each strip?
Trying to position the controller(s) close to the strips. I suppose it would be feasible to use one SPI port and 24 select lines, but the SPI port would need to run at nearly 3 megabits.
Quote from: mhenstell on Apr 26, 2012, 09:09 pmTrying to position the controller(s) close to the strips. I suppose it would be feasible to use one SPI port and 24 select lines, but the SPI port would need to run at nearly 3 megabits.That should be theoretically possible right? The SPI runs at a maximum frequency of system clock/2, so that's 8Mhz, and you only need 2.7Mhz. For select lines...I think you can use a 5x32 decoder out of 4028s.
What content will be displayed? If you go with a multi-microcontroller solution will they need to exchange data (or have a master)?
I don't think I can even get that amount of data through the FTDI.
In any case, you will want to size the outbound data to be evenly divisible into full USB frames. I believe not-full-frames are held for a few milliseconds (Nagle's algorithm meets USB).