The new display features eight 7-segment displays arranged in two rows of four digits. The on-board MAX7219 driver enables you to easily add eight 7-segment LED displays to your project using only 3 I/O pins of microcontroller. The major advantage of using this board is the time-division multiplexing operations required for continuous refreshing of the display digits are performed by the MAX7219 chip, thereby keeping the microcontroller free for doing other pressing tasks. It is suitable for displaying two variable values simultaneously in a project, such as displaying temperature and humidity, or current and voltage, etc.
We like the idea behind this project, but with a price tag of $12+ for the MAX7219 it isn’t cheap.
Update; Raj is selling 5 kits constituting of the PCB, displays and MAX7219 for $11.99, which is a bargain considering that just the MAX7219 is $12+ dollars in the ones at Mouser.