I agree that florinc's code is better than mine by far. I bought my first arduino, resistors, led matrix, motor, etc... two weeks ago. Also my C/C++ knowledge comes from universisty(6 months of basic stuff), I never did something real in C/C++.
To make dual board work, yes, you have to set X_MAX to 64.
If you copy the playground code(I did this just to check if the code there works perfectly), it'll work. Just don't use the RTC code, don't initialize on setup() and take it off from loop(). You can print any character in any color. Also check that my arduino pins are 50,51,52,53, maybe yours is on different pins!
e.g: put these lines on loop()
char STRING1[ ]="TIM ";
char STRING2[ ]="GILMORE ";
int x,i,j;
for(x=1;x<sizeof(STRING1);x++) {
null_buffer();
for(i=0;i<8;i++){
for(j=0;j<8;j++){
set_buffer(STRING1[x-1]);
if (~buffer[i][j] & (1<<0)) {
ht1632_plot(j+(8*(x-1))-1,i,RED);
} else {
ht1632_plot(j+(8*(x-1))-1,i,BLACK);
}
}
}
}
for(x=1;x<sizeof(STRING2);x++) {
null_buffer();
for(i=0;i<8;i++){
for(j=0;j<8;j++){
set_buffer(STRING2[x-1]);
if (~buffer[i][j] & (1<<0)) {
ht1632_plot(j+(8*(x-1))-1,i+8,GREEN);
} else {
ht1632_plot(j+(8*(x-1))-1,i+8,BLACK);
}
}
}
}
delay(10000);