What is your go to RGB LED driver?

T Chap

I am looking at a common anode LED built into a pushbutton. I want to put from any combination of 4 buttons up to 32 on a module. What are you guys using for controlling this type of LED from the Prop?

http://www.digikey.com/product-detail/en/KP0115ANBKG03RGB-2SJB/360-2465-ND/2355693

tomcrawford

1. I would think you would want to multiplex the LEDs; if so you need honkin' pull-up transistors. I have used Mitsu M54564 eight-to-a-package successfully. You can drive them directly from Prop output pins. If you decide not to mux, you could just tie the anodes directly to Vcc.

2. You need to decide whether you want just eight colors or lots of colors. If just eight colors you could use shift registers for pull-downs with fixed resistor to limit current. If you want lots of colors you can use constant current like TI TLC5916 for pull-downs.

0. That's a mighty fancy switch you found there.

Mag748

T Chap wrote: »

I am looking at a common anode LED built into a pushbutton. I want to put from any combination of 4 buttons up to 32 on a module. What are you guys using for controlling this type of LED from the Prop?

http://www.digikey.com/product-detail/en/KP0115ANBKG03RGB-2SJB/360-2465-ND/2355693

Hey there,

That is a decent switch. I've used a few of these and a bunch of the R/G only versions. They're just so dang expensive. I use the TLC5947DAP for driving the LEDs and the CD74HC165M96 to read the switches. I have some code snippets I can lend you if you decide to go that route.

Thanks,
Marcus

T Chap

Thanks for the links. I will use my fav PCF8575 16 bit i2c to read. I want 8 bits per color ideally. I wish there were a cheaper RGB button for less but I turned up nothing. If there is a cheaper one I'd love to see it. I need at least 20 per row, maybe 2 rows used in some cases.

MJB

what about a WS2812 or similar RGB-LED drivers?

found this on Sparkfun - what a great key but seems retired

https://www.sparkfun.com/products/retired/8493


of course you can just multiplex with a either I2C extender or SPI type 595 shift register.

I want to put from any combination of 4 buttons up to 32 on a module

32 * 3 colors could be made into a matrix 16 * 6 using either 3 * xx595 shift register or 16 + 8 I2C extender.
number of colors the depends on your PWM.

or use this for the 16 * sink:
http://www.maximintegrated.com/en/products/all-products/archive/MAX16809.html

T Chap

I am liking this IC for 12 bit per color. TLC5940. Anyone used this?

http://www.ti.com/lit/ds/symlink/tlc5940.pdf