Adafruit Industries Adafruit Industries 16x24 Red LED Matrix Panel - Chainable HT1632C Driver
These LED panels take care of all the work of making a big matrix display. Each panel has six 8x8 red matrix modules, for a 16x24 matrix. The panel has a HT1632C chip on the back with does all the multiplexing work for you and has a 3-pin SPI-like serial interface to talk to it and set LEDs on or off(you cannot set the LED to be individually dimmed, as in 'grayscale'). There's a few extras as well, such as being able to change the brightness of the entire display, or blink the entire display at 1Hz.
Adafruit Industries 16x24 Red LED Matrix Panel - Chainable HT1632C Driver
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