An Arduino/ESP8266 display board for 3x2 788BS red led matrices connected to max7219 drivers. The IREG is higher than usual to reduce brightness, use a smaller resistor (maybe 30/40 K) for daylight applications.
Work in progress, comments are wellcome.
When used with MD_MAX72XX and MD_Parola libs this matrices are not one of the supported hardware types, but I was able to wire 1 and 1+1 on a breadboard and they work quite well with the correct settings.
See attached .TXT for details about connecting the 788BS matrix to the MAX7219 and use it with MD_MAX72xx + MD_Parola libs on arduino IDE.