After several attempts to make a scrolling text on the 8x8 matrix, I found the most complete manual on the Embedded Lab page : http://embedded-lab.com/blog/portable-bluetooth-enabled-scrolling-led-matrix-display-part-1/.
The device contains an Arduino nano, Bluetooth module for receiving data from the smartphone and 8x8 LED matrices driven by MAX7219.
Unlike there, I used ready-made 8x8 matrix modules with MAX7219 chip that can be purchase very cheap on Ebay or Alexpress. At the moment, I only had 7 modules, so I made a small modification of the code. An android application does not exist anymore on Google Play store, so you can download it from :
. It can control the speed of the scrolling, brightness of leds, pause, erase text, and several predefined text buttons.
In the end, I put the whole device in a box, which I made from a PVC material that I put on it with a black wallpaper.