RGB Matrix in Unison

I am a new fish, hello

I am trying to design a small experiential piece and while I have found no end of useful info on how to control and rgb matrix I have not seen my own specific needs addressed.

Actually, my needs are addressed but most designs seem overkill w/r/t my requirements.

I want an rgb matrix to phase through an rgb pwm spectrum (255 colours or so?) controled with input data that the arduino (uno) will receive.

SIMPLES! no?

Thing is, I don't need individual control. I want them, always, all to change together. All of the shield and shifter solutions seem excessive and expensive for my purpose. My only interest is that all of the LEDs and colours shine at the same luminosity, and in the same colour of course.

To start, an 8x8 or even 16x16 matrix would be fine.

Is there a cheap and easy(er) way to do this?

Much obliged, Ian

Connect all the Common pins together. If you have Common Cathode RGB LEDs this would be the Cathodes. If you have Common Anode RGB LEDs this would be the Anodes. Connect each color through an appropriate current limiting resistor to a common point for that color.

For Common Anode: connect the + side of a hefty 5V supply to the Common Anodes. Connect each color’s Cathodes through an NPN transistor to the Arduino Ground and the - side of the hefty 5V supply.

For Common Cathode: connect the - side of a hefty 5V supply to the Common Cathodes and Arduino Ground. Connect + side of the hefty 5V supply through a PNP transistor to the Anodes for each color. Note that the PWM will be reversed: 0 = ON and 255 = OFF.

The Arduino PWM pins connect through a 220 Ohm resistor to the Base of the transistor.

Thanks John!

It's for a chromatic clock fyi