8x8_led_matrix_with_2x74hc595
This is the customized code that I found on the Arduino website using two shift registers (74HC595) and the Arduino MEGA 2560, a 16x2 LCD display and 4 buttons to control a 64 LED matrix, I changed the code and added lots of comments where necessary to explain the changes I had to make and add to get this working on the Arduino Nano.