Hello, I bought a 64x16 matrix display on ebay and I used code:
// Arduino 1.0.5 UNO R3
#include <pgmspace.h>
// Connections to board
const byte latchPin=8;
const byte clockPin=46;
const byte data_R1=40;
const byte data_R2=41;
const byte en_74138=22;
const byte la_74138=23;
const byte lb_74138=24;
const byte lc_74138=25;
const byte ld_74138=26;
byte ScanRow = 0;
unsigned long counter;
//Insert message here ("message ")
const char message[] = "TEST ARDUINO MEGA ";
byte buffer[256] = { // Display buffer (which is scanned by the interrupt timer) of 8x32 bytes
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
// ---------------------------------------------------------------------------------------------------
// FONTS sourced from various locations on the internet
// full ASCII character set (8x16) (1520 bytes)
const uint8_t font8x16_basic[] 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,
};
// Routine to print a single character in one of 8 columns
// Inputs:
// x is one of (0,16,24,32,40,48,56),
// y (0 to 16 or 24 depending upon font size),
// n is either (0 to 9) or an ascii value,
// font=0 for big font, 2 for small font,
// inverse is true for an inverted character
void drawChar(uint16_t x, uint16_t y, byte n, byte font, boolean inverse) {
byte charbytes[16], fontrows, xover8 = x>>3;
int index;
if (0 != (x % 8)) return; // x not a multiple of 8
if ((n>9) && (n<32)) return; // invalid character
if (font==0) fontrows=16; else fontrows=8;
if ((n>=0) && (n<=9)) index=(n+16)*fontrows; else index=(n-32)*fontrows; // go to the right code for this character
// addressing start at buffer and add y (rows) * (WIDTH is 64 so WIDTH/8) is 8 plus (x / 8) is 0 to 7
byte *pDst = buffer + (y << 3) + xover8;
for (byte i=0;i<fontrows;i++) { // fill up the charbytes array with the right bits
if (font==0) charbytes[i] = pgm_read_byte(&(font8x16_basic[index+i]));
// reverse bit order for fonts 0 and 1
if (font != 0) {
charbytes[i] = (charbytes[i] & 0xF0) >> 4 | (charbytes[i] & 0x0F) << 4;
charbytes[i] = (charbytes[i] & 0xCC) >> 2 | (charbytes[i] & 0x33) << 2;
charbytes[i] = (charbytes[i] & 0xAA) >> 1 | (charbytes[i] & 0x55) << 1;
};
if (inverse) charbytes[i] = ~charbytes[i];
};
const byte *pSrc = charbytes; // point at the first set of 8 pixels
for (byte i=0; i<fontrows; i++) {
*pDst = *pSrc; // populate the destination byte
pDst += 8; // go to next row on buffer
pSrc++; // go to next set of 8 pixels in character
}
};
void moveLeft(byte pixels, byte rowstart, byte rowstop) { // routine to move certain rows on the screen "pixels" pixels to the left
byte row, column;
short unsigned int address;
for (column=0;column<8;column++) {
for (row=rowstart;row<rowstop;row++) {
address = (row<<3) + column; /// right here!
if (column==7)
buffer[address] = buffer[address]<<pixels; // shuffle pixels left on last column and fill with a blank
else { // shuffle pixels left and add leftmost pixels from next column
byte incomingchar = buffer[address+1];
buffer[address] = buffer[address]<<pixels;
for (byte x=0;x<pixels;x++) { buffer[address] += ((incomingchar & (128>>x)) >> (7-x))<<(pixels-x-1); };
}
}
}
};
void shiftOut(byte row) { // fast routine to shove out 8 columns into two rows via board's shift registers
for(byte column=0;column<8;column++) {
byte index = column + (row<<3);
for(byte i=0;i<8;i++) {
PORTB &=~(3UL<<(data_R1-8)); // data_R2 is LOW; data_R1 is LOW;
PORTB &=~(1UL<<(clockPin-8)); // digitalWrite(clockPin,LOW);
PORTB |= !((buffer[index]>>(7-i)) & 0x01) << (data_R1-8); // top set of rows
PORTB |= !((buffer[index+128]>>(7-i)) & 0x01) << (data_R2-8); // bottom set of rows
PORTB |= 1<<(clockPin-8); // digitalWrite(clockPin,HIGH);
};
};
};
ISR(TIMER2_COMPA_vect){
cli();
digitalWrite(en_74138, HIGH); // Turn off display
shiftOut(ScanRow); // Shift out 8 columns
digitalWrite(latchPin, LOW);
digitalWrite(latchPin, HIGH);
PORTD = (ScanRow << 3) | (PORTD & 0X87); // Highlight row: pins 3 4 5 6 (la_74138 lb_74138 lc_74138 ld_74138)
digitalWrite(en_74138, LOW); // Turn on display
ScanRow++; // Do the next pair of rows next time this routine is called
if (ScanRow==16) ScanRow=0;
sei();
};
void setup() {
// Set up 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 pairs of rows)
OCR2A = 97; // 97 = (16,000,000 / (1024*160)) - 1
TCCR2A |= (1 << WGM21); TIMSK2 |= (1 << OCIE2A);
pinMode(latchPin,OUTPUT); pinMode(clockPin,OUTPUT);
pinMode(data_R1,OUTPUT); pinMode(data_R2,OUTPUT);
pinMode(en_74138,OUTPUT);
pinMode(la_74138,OUTPUT); pinMode(lb_74138,OUTPUT);
pinMode(lc_74138,OUTPUT); pinMode(ld_74138,OUTPUT);
digitalWrite(en_74138, LOW);
digitalWrite(data_R1, HIGH); digitalWrite(data_R2, HIGH);
counter = millis();
sei(); //allow interrupts
};
void loop() {
static int count=0;
// display next character of message
drawChar(56,0,message[count%(sizeof(message)-1)],0,false);
count = (count + 1);
// move the text 7 pixels (not 8 because it looks better) to the left
for (byte i=0; i<4; i++) {
delay(80);
moveLeft(2,1,32);
};
};
the problem is that this code works fine on arduino uno but due to necessity I upgraded to arduino mega and now it's no longer working (I just get a strange line of pixel on) and it's giving this warnings:
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino: In function 'void shiftOut(byte)':
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino:198:32: warning: left shift count >= width of type [-Wshift-count-overflow]
PORTB &=~(3UL<<(data_R1-8)); // data_R2 is LOW; data_R1 is LOW;
^
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino:199:33: warning: left shift count >= width of type [-Wshift-count-overflow]
PORTB &=~(1UL<<(clockPin-8)); // digitalWrite(clockPin,LOW);
^
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino:200:62: warning: left shift count >= width of type [-Wshift-count-overflow]
PORTB |= !((buffer[index]>>(7-i)) & 0x01) << (data_R1-8); // top set of rows
^
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino:201:66: warning: left shift count >= width of type [-Wshift-count-overflow]
PORTB |= !((buffer[index+128]>>(7-i)) & 0x01) << (data_R2-8); // bottom set of rows
^
C:\Users\Mattia\Desktop\Text_scroll-working\Text_scroll-working.ino:202:30: warning: left shift count >= width of type [-Wshift-count-overflow]
PORTB |= 1<<(clockPin-8); // digitalWrite(clockPin,HIGH);
Could someone help me to figure out what's wrong and how to fix it? Thank you