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Topic: Shift Registry Question (Read 2 times) previous topic - next topic

CrossRoads

#5
Oct 10, 2012, 06:20 am Last Edit: Oct 10, 2012, 06:22 am by CrossRoads Reason: 1
You could also look at WS2803, can drive 18 LEDs (or 6 RGB LEDs) each.

These guys are the only ones carrying them that I've seen.
I bought 25 (DIP) recently but haven't done anything with them yet.

http://stores.ebay.com/NooElec/_i.html?_nkw=ws2803&submit=Search&_sid=32165772
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Computer991

Thanks for the reply I was reading through the datasheet and as a newbie to electronics I have no clue what most of it ment  but thank you for clearing some of it up, ill definite print this up and give it a good read.

Also @ Crossroads wow those chips are awesome I really wish I had seen those earlier they are great for the price...Ill try to use them on my next run quick question tho are they compatible with the WS2801 or would I have to use different systems for the chips?

CrossRoads

Supposed to be compatible - Haven't read the datasheet in detail, I would imagine you just send out 6x more of the same type of data vs WS2801.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

dhenry

A big plus for hc595 is the output latch: it allows the display to be updated once, thus no flickering. Not to mention its wide availability. But you cannot (practically) manage grayscale for individual bits - you can manage the grayscale for all bits, however.

A big plus for ws280x is the ability to manage grayscale for individual bits. However, their output is transparent so the display gets updated as the data is piped in. Not to mention the gap time between each frame.

So if you need to drive individual leds differently (uneven leds for example), go with ws280x (the issue for large number of leds driven by ws280x is the long transfer time -> flickering). Otherwise, hc595 is a better choice.



CrossRoads

Another option - use MAX7219, can drive 64 LEDs.  All will have the same  31 level of intensity control. It does the multiplexing at 800 Hz, no flickering. Update with SPI transfers, nice & fast. 4 chips driving 256 LEDs, make them the high brightness kind, light up your room pretty nice!
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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