Matrix Power Requirements

The power management is not done on-board. Instead you will have to provide the 5V 10A+ power separately! We recommend two power distribution bus bars, they're good for many amps and make wiring easier.

LED matrix panels require 5V power and a lot of it! 5V 2A at a minimum and you can easily need a 5V 4A or 5V 10A supply for big stretches of panels!

Each matrix has 64 pixels (16x32 or 32x32 panels) or 128 pixels (for the 32x64 panels) lit at one time (due to “scanning” the rows sequentially). Each pixel can briefly draw up to 0.06 Amps each if on full white. The total max per panel is thus 64 * 0.06 = 3.95 Amps or 128 * 0.06 = 7.68 Amps

That's if all the LEDs are on at once, which is not likely - but still, it's good to have at least half for the power supply in case you get bright!

Matrix Drive Pins

The matrix does not work like 'smart' pixels you may have used, like NeoPixels or DotStars or LPD8806 or WS2801 or what have you. The matrix panels are very 'dumb' and have no memory or self-drawing capability.

Data must be constantly streamed to the matrix for an image to display! So all of these pins are always used when drawing to the display

All these pins go thru a 74AHCT245 level shifter to convert the 3.3V logic from the Pi to the 5V logic required by the panels

Shared Pins

The matrix control pins, and address pins are shared between all 3 of the ports.

Control Pins:

• Pi GPIO #18 - Matrix OE (output enable) pin
  This pin controls whether the LEDs are lit at all
• Pi GPIO #17 - Matrix CLK (clock) pin
  This pin is the high speed clock pin for clocking RGB data to the matrix
• Pi GPIO #4 - Matrix LAT (latch) pin
  This pin is the data latching pin for clocking RGB data to the matrix

Address Pins:

• Pi GPIO #22 - Matrix A (address A) pin
  This pin is part of the 1->32, 1->16 or 1->8 multiplexing circuitry.
• Pi GPIO #23 - Matrix B (address B) pin
  This pin is part of the 1->32, 1->16 or 1->8 multiplexing circuitry.
• Pi GPIO #24 - Matrix C (address C) pin
  This pin is part of the 1->32, 1->16 or 1->8 multiplexing circuitry.
• Pi GPIO #25 - Matrix D (address D) pin
  This pin is part of the 1->32, 1->16 multiplexing circuitry. Used for 32-pixel and 64-pixel tall displays only
• Pi GPIO #15/RxD - Matrix E (address E) pin
  This pin is part of the 1->32 multiplexing circuitry. Used for 64-pixel tall displays only. Behavior is controlled by the slide switch. See below for details.

Port 1 Matrix Color Pins

Port 2 Matrix Color Pins

Port 3 Matrix Color Pins

Power Pins Addr E Switch & STEMMA QT

In the lower left corner of the board there are some exposed power pins, a switch for controlling address E, and a STEMMA QT port.

Power Pins

• 5 - 5V power
• 3 - 3V power
• G - GND

Address E Switch

When using with 64x64 matrices, you can select whether the Address E pin is on the 4th or 8th IDC pad with this on-board switch. If your panels aren't displaying properly, try switching this to the other position.

STEMMA QT

There is a STEMMA QT port available, but keep in mind the SDA and SCL pins are also used by Matrix port 3, so you cannot use both at the same time.