Arduino LED Matrix 16 x 128 three colors

led_matrix_16x128.ino

#include <avr/pgmspace.h>
#include "pins_arduino.h"

// based on myMatrix Arduino Library
// by Silviu - www.openhardware.ro
// MIT License (MIT)

// Connections to board
const byte pinSTB=8;
const byte pinClock=12;
const byte pinRed=10;
const byte pinGreen=11;
const byte pinOE=2;
const byte pinRowA=3;
const byte pinRowB=4;
const byte pinRowC=5;
const byte pinRowD=6;

byte scanRow = 0;
unsigned long counter;

//Insert message here ("message ")
char message[] = "                Challenge ACCEPTED!!!        ";

// ---------------------------------------------------------------------------------------------------
const byte RED    = 0b10;
const byte GREEN  = 0b01;
const byte YELLOW = 0b11;
const byte BLACK  = 0b00;

struct Color {
  byte R;
  byte G;
};

#define BUFFER_INIT_256 BUFFER_INIT_128 BUFFER_INIT_128
#define BUFFER_INIT_128 BUFFER_INIT_100 BUFFER_INIT_10 BUFFER_INIT_10 BUFFER_INIT_8
#define BUFFER_INIT_100 BUFFER_INIT_50 BUFFER_INIT_50
#define BUFFER_INIT_50  BUFFER_INIT_10 BUFFER_INIT_10 BUFFER_INIT_10 BUFFER_INIT_10 BUFFER_INIT_10
#define BUFFER_INIT_10  BUFFER_INIT_2 BUFFER_INIT_2 BUFFER_INIT_2 BUFFER_INIT_2 BUFFER_INIT_2
#define BUFFER_INIT_8   BUFFER_INIT_2 BUFFER_INIT_2 BUFFER_INIT_2 BUFFER_INIT_2
#define BUFFER_INIT_2   BUFFER_INIT_1 BUFFER_INIT_1
#define BUFFER_INIT_1   {0x00, 0x00},

Color buffer[256] = {BUFFER_INIT_256};
// ---------------------------------------------------------------------------------------------------


// FONTS sourced from various locations on the internet
// full ASCII character set (8x16) (1520 bytes)
static const uint8_t font8x16_basic[96][16] PROGMEM = {
  /*   (32) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},  
  /* ! (33) */ {0x00, 0x00, 0x00, 0x18, 0x3C, 0x3C, 0x3C, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00},
  /* " (34) */ {0x00, 0x00, 0x66, 0x66, 0x66, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* # (35) */ {0x00, 0x00, 0x00, 0x00, 0x6C, 0x6C, 0xFE, 0x6C, 0x6C, 0x6C, 0xFE, 0x6C, 0x6C, 0x00, 0x00, 0x00},
  /* $ (36) */ {0x00, 0x18, 0x18, 0x7C, 0xC6, 0xC2, 0xC0, 0x7C, 0x06, 0x06, 0x86, 0xC6, 0x7C, 0x18, 0x18, 0x00},    
  /* % (37) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0xC2, 0xC6, 0x0C, 0x18, 0x30, 0x60, 0xC6, 0x86, 0x00, 0x00, 0x00},
  /* & (38) */ {0x00, 0x00, 0x00, 0x38, 0x6C, 0x6C, 0x38, 0x76, 0xDC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00},
  /* ' (39) */ {0x00, 0x00, 0x30, 0x30, 0x30, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* ( (40) */ {0x00, 0x00, 0x00, 0x0C, 0x18, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x18, 0x0C, 0x00, 0x00, 0x00},
  /* ) (41) */ {0x00, 0x00, 0x00, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x18, 0x30, 0x00, 0x00, 0x00},
  /* * (42) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* + (43) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x7E, 0x18, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* , (44) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x18, 0x30, 0x00, 0x00},
  /* - (45) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* . (46) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00},
  /* / (47) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0x80, 0x00, 0x00, 0x00},
  /* 0 (48) */ {0x00, 0x00, 0x00, 0x3C, 0x66, 0xC3, 0xC3, 0xDB, 0xDB, 0xC3, 0xC3, 0x66, 0x3C, 0x00, 0x00, 0x00},
  /* 1 (49) */ {0x00, 0x00, 0x00, 0x18, 0x38, 0x78, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x7E, 0x00, 0x00, 0x00},
  /* 2 (50) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0xC6, 0xFE, 0x00, 0x00, 0x00},
  /* 3 (51) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0x06, 0x06, 0x3C, 0x06, 0x06, 0x06, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* 4 (52) */ {0x00, 0x00, 0x00, 0x0C, 0x1C, 0x3C, 0x6C, 0xCC, 0xFE, 0x0C, 0x0C, 0x0C, 0x1E, 0x00, 0x00, 0x00},
  /* 5 (53) */ {0x00, 0x00, 0x00, 0xFE, 0xC0, 0xC0, 0xC0, 0xFC, 0x06, 0x06, 0x06, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* 6 (54) */ {0x00, 0x00, 0x00, 0x38, 0x60, 0xC0, 0xC0, 0xFC, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* 7 (55) */ {0x00, 0x00, 0x00, 0xFE, 0xC6, 0x06, 0x06, 0x0C, 0x18, 0x30, 0x30, 0x30, 0x30, 0x00, 0x00, 0x00},
  /* 8 (56) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* 9 (57) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0x7E, 0x06, 0x06, 0x06, 0x0C, 0x78, 0x00, 0x00, 0x00},
  /* : (58) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x00},
  /* ; (59) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x18, 0x18, 0x30, 0x00, 0x00, 0x00},
  /* < (60) */ {0x00, 0x00, 0x00, 0x00, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x30, 0x18, 0x0C, 0x06, 0x00, 0x00, 0x00},
  /* = (61) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* > (62) */ {0x00, 0x00, 0x00, 0x00, 0x60, 0x30, 0x18, 0x0C, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x00, 0x00, 0x00},
  /* ? (63) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0x0C, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00},
  /* @ (64) */ {0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xDE, 0xDE, 0xDE, 0xDC, 0xC0, 0x7C, 0x00, 0x00, 0x00},
  /* A (65) */ {0x00, 0x00, 0x00, 0x10, 0x38, 0x6C, 0xC6, 0xC6, 0xFE, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00},
  /* B (66) */ {0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x66, 0x66, 0x66, 0x66, 0xFC, 0x00, 0x00, 0x00},
  /* C (67) */ {0x00, 0x00, 0x00, 0x3C, 0x66, 0xC2, 0xC0, 0xC0, 0xC0, 0xC0, 0xC2, 0x66, 0x3C, 0x00, 0x00, 0x00},
  /* D (68) */ {0x00, 0x00, 0x00, 0xF8, 0x6C, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x6C, 0xF8, 0x00, 0x00, 0x00},
  /* E (69) */ {0x00, 0x00, 0x00, 0xFE, 0x66, 0x62, 0x68, 0x78, 0x68, 0x60, 0x62, 0x66, 0xFE, 0x00, 0x00, 0x00},
  /* F (70) */ {0x00, 0x00, 0x00, 0xFE, 0x66, 0x62, 0x68, 0x78, 0x68, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00},
  /* G (71) */ {0x00, 0x00, 0x00, 0x3C, 0x66, 0xC2, 0xC0, 0xC0, 0xDE, 0xC6, 0xC6, 0x66, 0x3A, 0x00, 0x00, 0x00},
  /* H (72) */ {0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xFE, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00},
  /* I (73) */ {0x00, 0x00, 0x00, 0x3C, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00},
  /* J (74) */ {0x00, 0x00, 0x00, 0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0xCC, 0xCC, 0xCC, 0x78, 0x00, 0x00, 0x00},
  /* K (75) */ {0x00, 0x00, 0x00, 0xE6, 0x66, 0x66, 0x6C, 0x78, 0x78, 0x6C, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00},
  /* L (76) */ {0x00, 0x00, 0x00, 0xF0, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x62, 0x66, 0xFE, 0x00, 0x00, 0x00},
  /* M (77) */ {0x00, 0x00, 0x00, 0xC3, 0xE7, 0xFF, 0xFF, 0xDB, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0x00, 0x00, 0x00},
  /* N (78) */ {0x00, 0x00, 0x00, 0xC6, 0xE6, 0xF6, 0xFE, 0xDE, 0xCE, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00},
  /* O (79) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* P (80) */ {0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x60, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00},
  /* Q (81) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xD6, 0xDE, 0x7C, 0x0C, 0x0E, 0x00},
  /* R (82) */ {0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x6C, 0x66, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00},
  /* S (83) */ {0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0x60, 0x38, 0x0C, 0x06, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* T (84) */ {0x00, 0x00, 0x00, 0xFF, 0xDB, 0x99, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00},
  /* U (85) */ {0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* V (86) */ {0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x00, 0x00, 0x00},
  /* W (87) */ {0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xDB, 0xDB, 0xFF, 0x66, 0x66, 0x00, 0x00, 0x00},
  /* X (88) */ {0x00, 0x00, 0x00, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x18, 0x3C, 0x66, 0xC3, 0xC3, 0x00, 0x00, 0x00},
  /* Y (89) */ {0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00},
  /* Z (90) */ {0x00, 0x00, 0x00, 0xFF, 0xC3, 0x86, 0x0C, 0x18, 0x30, 0x60, 0xC1, 0xC3, 0xFF, 0x00, 0x00, 0x00},
  /* [ (91) */ {0x00, 0x00, 0x00, 0x3C, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x3C, 0x00, 0x00, 0x00},
  /* \ (92) */ {0x00, 0x00, 0x00, 0x00, 0x80, 0xC0, 0xE0, 0x70, 0x38, 0x1C, 0x0E, 0x06, 0x02, 0x00, 0x00, 0x00},
  /* ] (93) */ {0x00, 0x00, 0x00, 0x3C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x3C, 0x00, 0x00, 0x00},
  /* ^ (94) */ {0x00, 0x10, 0x38, 0x6C, 0xC6, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* _ (95) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00},
  /* ` (96) */ {0x00, 0x30, 0x30, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* a (97) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x78, 0x0C, 0x7C, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00},
  /* b (98) */ {0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x78, 0x6C, 0x66, 0x66, 0x66, 0x66, 0x7C, 0x00, 0x00, 0x00},
  /* c (99) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC0, 0xC0, 0xC0, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* d (100) */ {0x00, 0x00, 0x00, 0x1C, 0x0C, 0x0C, 0x3C, 0x6C, 0xCC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00},
  /* e (101) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xFE, 0xC0, 0xC0, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* f (102) */ {0x00, 0x00, 0x00, 0x38, 0x6C, 0x64, 0x60, 0xF0, 0x60, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00},
  /* g (103) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x76, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x7C, 0x0C, 0xCC, 0x78},
  /* h (104) */ {0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x6C, 0x76, 0x66, 0x66, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00},
  /* i (105) */ {0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x38, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00},
  /* j (106) */ {0x00, 0x00, 0x00, 0x06, 0x06, 0x00, 0x0E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x66, 0x66, 0x3C},
  /* k (107) */ {0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x66, 0x6C, 0x78, 0x78, 0x6C, 0x66, 0xE6, 0x00, 0x00, 0x00},
  /* l (108) */ {0x00, 0x00, 0x00, 0x38, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00},
  /* m (109) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE6, 0xFF, 0xDB, 0xDB, 0xDB, 0xDB, 0xDB, 0x00, 0x00, 0x00},
  /* n (110) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x00, 0x00, 0x00},
  /* o (111) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* p (112) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x66, 0x66, 0x66, 0x66, 0x66, 0x7C, 0x60, 0x60, 0xF0},
  /* q (113) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x76, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x7C, 0x0C, 0x0C, 0x1E},
  /* r (114) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x76, 0x66, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00},
  /* s (115) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0x60, 0x38, 0x0C, 0xC6, 0x7C, 0x00, 0x00, 0x00},
  /* t (116) */ {0x00, 0x00, 0x00, 0x10, 0x30, 0x30, 0xFC, 0x30, 0x30, 0x30, 0x30, 0x36, 0x1C, 0x00, 0x00, 0x00},
  /* u (117) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00},
  /* v (118) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x00, 0x00, 0x00},
  /* w (119) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xDB, 0xDB, 0xFF, 0x66, 0x00, 0x00, 0x00},
  /* x (120) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0x66, 0x3C, 0x18, 0x3C, 0x66, 0xC3, 0x00, 0x00, 0x00},
  /* y (121) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7E, 0x06, 0x0C, 0xF8},
  /* z (122) */ {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0xCC, 0x18, 0x30, 0x60, 0xC6, 0xFE, 0x00, 0x00, 0x00},
  /* { (123) */ {0x00, 0x00, 0x00, 0x0E, 0x18, 0x18, 0x18, 0x70, 0x18, 0x18, 0x18, 0x18, 0x0E, 0x00, 0x00, 0x00},
  /* | (124) */ {0x00, 0x00, 0x00, 0x18, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x18, 0x18, 0x00, 0x00, 0x00},
  /* } (125) */ {0x00, 0x00, 0x00, 0x70, 0x18, 0x18, 0x18, 0x0E, 0x18, 0x18, 0x18, 0x18, 0x70, 0x00, 0x00, 0x00},
  /* ~ (126) */ {0x00, 0x00, 0x00, 0x76, 0xDC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  /* BLK(127)*/ {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
};


// function to colorize a pixel
// color 2 Bit, (R)ed (G)reen 0b000000RG
void setPixel(uint8_t x ,uint8_t y, uint8_t color)
{
  uint8_t myindex = (y*16)+x/8;  // 16 segments per row
  uint8_t mybitmask = 7 -(x % 8);
  bitWrite(buffer[myindex].R, mybitmask, (color & 0b00000010));  // red
  bitWrite(buffer[myindex].G, mybitmask, (color & 0b00000001));  // green
}


// function to print a character at column
void printChar(uint8_t x_offset, uint8_t fg_color, uint8_t bg_color, byte ch) {
  if (0 != (x_offset % 8)) return;    // x_offset not a multiple of 8
  if ((ch>9) && (ch<32)) return; // invalid character
  const uint8_t y_offset = 0;
  for (uint8_t y=0; y<16; y++){
    for (uint8_t i=0; i<8; i++){
      if(bitRead(pgm_read_byte(&font8x16_basic[ch-32][y]),7-i)) setPixel(x_offset+i, y_offset+y, fg_color);
      else setPixel(x_offset+i, y_offset+y, bg_color);        
    }
  }  
}


// function to scrol the text message to the left
void hScroll(uint8_t fg_color, uint8_t bg_color, char *mystring){
  // offset starts with 0
  // this means text starts in upper left corner
  for (int offset=0; offset < ((lenString(mystring)-8)*8-1); offset++){
    for (byte x=0; x<128; x++){  // 128
      for (byte y=0; y<16; y++){
        byte color=bg_color;
        if (getPixelMessage(x+offset,y,mystring)) color=fg_color;
        setPixel(x,y,color);
      }
    }
    delay(40);  
  }
}


byte getPixelMessage(uint16_t x, uint16_t y, char *p){
  p=p+x/8;
  return getPixelChar(x%8, y, *p);
}


byte getPixelChar(uint8_t x, uint8_t y, char ch){
  return bitRead(pgm_read_byte(&font8x16_basic[ch-32][y]),7-x);
}


// length of the message string
uint8_t lenString(char *p){
  unsigned int retVal=0;
  while(*p!='\0'){ 
   retVal++;
   p++;
  }
  return retVal;
}

void drawRectangle(uint16_t x1, uint16_t y1, uint16_t x2, uint16_t y2, uint8_t color){
    drawHLine(x1,x2,y1,color);
    drawHLine(x1,x2,y2,color);  
    drawVLine(x1,y1,y2,color);
    drawVLine(x2,y1,y2,color);
}

void drawVLine(uint16_t x, uint16_t y1, uint16_t y2, uint8_t color){
    for (uint16_t y = y1; y <= y2; y++) {
        setPixel(x,y,color);      
    }
}

void drawHLine(uint16_t x1, uint16_t x2, uint16_t y, uint8_t color){
    for (uint16_t x = x1; x <= x2; x++) {
          setPixel(x,y,color);      
    }  
}

void clearScreen(){
    for (uint8_t i=0; i<256; i++)  // buffer size
    {
      buffer[i].R=0;
      buffer[i].G=0; 
    }
}




// helper function to paint one row
void shiftOut(uint8_t row) {
  const uint8_t bitRed = digitalPinToBitMask(pinRed);
  volatile uint8_t *outRed = portOutputRegister(digitalPinToPort(pinRed));

  const uint8_t bitGreen = digitalPinToBitMask(pinGreen);
  volatile uint8_t *outGreen = portOutputRegister(digitalPinToPort(pinGreen));

  const uint8_t bitClock = digitalPinToBitMask(pinClock);
  volatile uint8_t *outClock = portOutputRegister(digitalPinToPort(pinClock));

  const uint8_t bitRowA = digitalPinToBitMask(pinRowA);
  volatile uint8_t *outRowA = portOutputRegister(digitalPinToPort(pinRowA));

  const uint8_t bitRowB = digitalPinToBitMask(pinRowB);
  volatile uint8_t *outRowB = portOutputRegister(digitalPinToPort(pinRowB));

  const uint8_t bitRowC = digitalPinToBitMask(pinRowC);
  volatile uint8_t *outRowC = portOutputRegister(digitalPinToPort(pinRowC));

  const uint8_t bitRowD = digitalPinToBitMask(pinRowD);
  volatile uint8_t *outRowD = portOutputRegister(digitalPinToPort(pinRowD));

  const uint8_t bitOE = digitalPinToBitMask(pinOE);
  volatile uint8_t *outOE = portOutputRegister(digitalPinToPort(pinOE));

  const uint8_t bitSTB = digitalPinToBitMask(pinSTB);
  volatile uint8_t *outSTB = portOutputRegister(digitalPinToPort(pinSTB));  
  
  *outOE |= bitOE;  // Turn off display  // digitalWrite(pinOE,HIGH);
  // select row
  if (bitRead(row, 0)) *outRowA |= bitRowA; else *outRowA &= ~bitRowA;
  if (bitRead(row, 1)) *outRowB |= bitRowB; else *outRowB &= ~bitRowB;
  if (bitRead(row, 2)) *outRowC |= bitRowC; else *outRowC &= ~bitRowC;
  if (bitRead(row, 3)) *outRowD |= bitRowD; else *outRowD &= ~bitRowD;

  for(uint8_t column=0; column<16; column++){  // 16 segments
    uint8_t index = column + (row*16);  // 16 segments
    for(uint8_t i=0; i<8; i++) {    
      if (buffer[index].R & (1<<(7-i))) *outRed &= ~bitRed;
      else *outRed |= bitRed;
      
      if (buffer[index].G & (1<<(7-i))) *outGreen &= ~bitGreen;
      else *outGreen |= bitGreen;
      
      //Clock Pulse
      *outClock |= bitClock; //CLK, HIGH
      *outClock &= ~bitClock; //CLK, LOW
    }
  }

  *outSTB &= ~bitSTB;  // digitalWrite(pinSTB,LOW);
  *outSTB |= bitSTB;   // digitalWrite(pinSTB,HIGH);
  *outOE &= ~bitOE;    // Turn on display  // digitalWrite(pinOE,LOW);
}


// interrupt routine is responsible for painting the screen
ISR(TIMER2_COMPA_vect){
  cli();
  shiftOut(scanRow);
  if (scanRow < 15) scanRow++; else scanRow = 0;
  sei();
}


void setup() {
  // use timer2 as the scanning interrupt timer
  cli(); // clear interrupts
  TCCR2A = 0; TCCR2B = 0; TCNT2  = 0;
  TCCR2B |= (1 << CS12) | (1 << CS10);     // Set 1024 prescaler
               // 160Hz scan rate = 10 frames/second (16 rows)
  OCR2A = 97;  // 97 = (16,000,000 / (1024*160)) - 1
  TCCR2A |= (1 << WGM21); TIMSK2 |= (1 << OCIE2A);
  
  pinMode(pinRed, OUTPUT); 
  pinMode(pinGreen, OUTPUT); 
  pinMode(pinClock, OUTPUT); 
  pinMode(pinRowA, OUTPUT); 
  pinMode(pinRowB, OUTPUT); 
  pinMode(pinRowC, OUTPUT); 
  pinMode(pinRowD, OUTPUT); 
  pinMode(pinOE, OUTPUT); 
  pinMode(pinSTB, OUTPUT); 

  digitalWrite(pinOE, LOW);
  digitalWrite(pinRed, HIGH); digitalWrite(pinGreen, HIGH);
  sei(); //allow interrupts
}


// main loop is responsible for updating the screen
void loop() {  
  //  printChar(0,GREEN,BLACK,'A');
  hScroll(YELLOW, BLACK, message);
}

Thanks for the code for this 16x128 3 color led matrix.

1. Would it be possible to change it to a 32x128 (i.e 2 panels of 32x64) 3 color led matrix?
   it looks like the one in the market such as https://www.aliexpress.com/item/33005142831.html?spm=a2g0o.cart.0.0.777d3c00odcu2v&mp=1 (1/16 scan rate - HUB08)
   have R1 R2 G1 G2 pins on the hub8 connector whereas you use R and G.
   for the single color 32x64 panel it's got R1 and R2. A small pcb connector connects the Arduino pins to the HUB8 but it doesn't have G1/G2 on the arduino side.

2. Do you know where to get this type of connector for Arduino? I am aware of the DMDCON from Freetronics but it uses SPI pins and is HUB12.

I note that in your ShiftOut function you use functions like: digitalPinTo BitMask and Port. Also potOutRegister. I assume your project works on UNO. but

3. do you know if these functions would works for MEG2560 and even the ESPDuino-32 ( Wemos D1 R32 ESP)?

Thanks in advance .