Prop RCB controller

Brian Carpenter · 2011-09-07 19:32

I know this is nothing new as i have seen it before... somewhere...

I have 48 RGB LEDs. i am making a 'spin the wheel' game for the office.
Currently i have a large 5' diameter that sits on an axle and pillow bearings. The employee spins the wheel to see what he/ she may win. The design has lasted a long time but is now in need of a revamp.
I would like to control each RGB LED independently so i can have them chase either direction or in a random pattern around the wheel.

What piece(s) of silicon would be most beneficial in my project to accomplish the above goals?

Mike Green · 2011-09-07 19:51

How about a bunch of TPIC6595s? These are functionally similar to the 74HC595, but include a power MOSFET on each output. You would need 18 in all: 8 per package for 48 x 3 (R,G,B) = 144.

There are other LED controllers. This one handles 16 channels and provides for constant current to the LEDs. You'd need 9 of these.

Brian Carpenter · 2011-09-07 20:01

thank you for the pointer in the right direction

tonyp12 · 2011-09-07 21:42

This one is made for RGB in mind.
http://www.ti.com/lit/ds/symlink/tlc5952.pdf
But you should also look for pin spacing you're comfortable with with like 1.27mm vs 0.65mm for size 'e'

But making you driver using regular 595(soursing) and 6595(or single n channel mosfets for sinking) and 144 resistors may be more fun.
Do you need full individual control of each led? or could each quarter of a circle be mirrored (common practice in game show displays)
And you could multiplex by using 36 sourcing ic pins with 4 sinking mosfets for a 25% duty as that will cut down on parts.

Rayman · 2011-09-08 06:06

You could also take a look at the PropRGB circuit on my website... It uses a Propeller to directly control 64 RGB LEDs with just a few low cost external components...

JasonDorie · 2011-09-08 11:58

The TLC5940 by Texas Instruments is similar to the 5929 that Mike posted, but has 10-bit PWM control per channel. They can be daisy chained together very easily, and there are ready-made drivers for them in the Obex. Tim Swieter's RGB Painter uses them, and he provides schematics and source code.

Tubular · 2011-09-08 19:23

Brian, I know you're probably intending on soldering discrete RGB LEDs, but just in case ....

There are now "addressable RGB led strips" for about $20-30/meter. These have about 32 led strips per metre, or 160 along a 5m length. They are flexible and some have double sided adhesive. Every led can be set to at least 8 colours, and many have 24 bit colour control. They need 3 or 4 prop pins to drive them using the props 3v3 logic, and a beefy 5v supply.

I have prop code for the Adafruit and Sparkfun addressable RGB varieties which I'm happy to share if you need.

Brian Carpenter · 2011-09-10 20:16

Tubular wrote: »

Brian, I know you're probably intending on soldering discrete RGB LEDs, but just in case ....

There are now "addressable RGB led strips" for about $20-30/meter. These have about 32 led strips per metre, or 160 along a 5m length. They are flexible and some have double sided adhesive. Every led can be set to at least 8 colours, and many have 24 bit colour control. They need 3 or 4 prop pins to drive them using the props 3v3 logic, and a beefy 5v supply.

I have prop code for the Adafruit and Sparkfun addressable RGB varieties which I'm happy to share if you need.

been out of town so sorry for the delay. Please share.

Tubular · 2011-09-15 00:15

Hi Brian
I've uploaded a new object for the Sparkfun addressable RGB strip (COM-10312).
It cycles a simple pattern through the 32 LEDs
The object is here

If you have any questions, please ask.

The Adafruit strip is not as advanced (8 colours instead of 16 million) ,but I'll do an object for it too, later.

Prop RCB controller

Comments