I found these neat 12×16 RGB LED matrixes (matrices?) from a company called “Saco technologies” at a local scientific surplus store. I have a bit of a project planned for them but for now I’ll post a bit of information I’ve managed to figure out about them if anyone else comes across these.

Here are the LEDs. I don’t have a clue what brand they are, but they sure are bright!

The panels come with a plastic diffuser that covers each LED.

And the interesting part – the back.

The LEDs are driven by 9 TLC5940, 16 channel LED drivers. Each row of drivers controls one color, alternating every third column of LEDs while the FETs switch between every fourth row of LEDs. Here is a quick drawing I made:

UPDATE: This drawing is wrong! See this new post for more accurate information: https://erykzagorski.com/index.php/2022/02/05/saco-led-matrix-update/

The TLC5940s are driven through a serial signal and have both a Sin and Sout signal. The three drivers for each color are daisy chained using these connections.

The line driver drives common signals for each TLC5940 like GSCLK, SCLK, BLANK, XLAT and VPRG. The Sin pin for the first drivers in the daisy chain are driven directly from the data header.

Here is the pinout of the data header:

Here is a sample of the panel running from an FPGA. I have paused my work on the project I had planned and this is basically as far as I got: