So I guess the title says it all, but to be more specific, I want to be able to display more than 8 custom characters on the LCD at one time. I know that you can just overwrite the CGRAM and make a new one if you want to print different characters at different times, but the problem that I run into is that the LCD is always referencing the CGRAM whenever it has to print the required characters to the screen however many times per second.
The LCD that I am using is one like this: 20x4 LCD (Amazon)
(I just have it connected using the 4 data lines, not via the I2C module)
So, the whole reason that I want to print more than 8 custom characters at once is that I'm trying to create a game of snake where there are 6 "dots" in every LCD "character". That makes a total of 64 different possible combinations of dots, which is a lot more than the maximum of 8 custom characters in the CGRAM.
My workaround for this was to edit a byte array that contains the information for the custom character to what is needed, then create the custom character in the CGRAM and after that, print it in the required place on the LCD. I would then reset the byte array and edit it once more for the next place on the LCD, then re-create the custom character in the same CGRAM address as before. In this way I was hoping to be able to print as many different combinations of dots to the LCD as I wanted, but this seems to not be the case.
Here is the code that I am using to do that:
void snake_print() {
byte print_x = 0;
byte print_y = 0;
for (byte char_y = 0; char_y < 12; char_y = char_y + 3) {
for (byte char_x = 0; char_x < 40; char_x = char_x + 2) {
byte snake_custom_char[8] = {0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b00000};
for (byte extra_y_char = 0; extra_y_char < 3; extra_y_char++) {
if ((lcd_objects[char_y + extra_y_char][char_x] > 0) && (lcd_objects[char_y + extra_y_char][char_x + 1] > 0)) {
if (extra_y_char == 0) {
snake_custom_char[0] = 0b11011;
snake_custom_char[1] = 0b11011;
} else if (extra_y_char == 1) {
snake_custom_char[3] = 0b11011;
snake_custom_char[4] = 0b11011;
} else if (extra_y_char == 2) {
snake_custom_char[6] = 0b11011;
snake_custom_char[7] = 0b11011;
}
} else if (lcd_objects[char_y + extra_y_char][char_x] > 0) {
if (extra_y_char == 0) {
snake_custom_char[0] = 0b11000;
snake_custom_char[1] = 0b11000;
} else if (extra_y_char == 1) {
snake_custom_char[3] = 0b11000;
snake_custom_char[4] = 0b11000;
} else if (extra_y_char == 2) {
snake_custom_char[6] = 0b11000;
snake_custom_char[7] = 0b11000;
}
} else if (lcd_objects[char_y + extra_y_char][char_x + 1] > 0) {
if (extra_y_char == 0) {
snake_custom_char[0] = 0b00011;
snake_custom_char[1] = 0b00011;
} else if (extra_y_char == 1) {
snake_custom_char[3] = 0b00011;
snake_custom_char[4] = 0b00011;
} else if (extra_y_char == 2) {
snake_custom_char[6] = 0b00011;
snake_custom_char[7] = 0b00011;
}
}
}
Serial.println(snake_custom_char[0], BIN);
Serial.println(snake_custom_char[1], BIN);
Serial.println(snake_custom_char[2], BIN);
Serial.println(snake_custom_char[3], BIN);
Serial.println(snake_custom_char[4], BIN);
Serial.println(snake_custom_char[5], BIN);
Serial.println(snake_custom_char[6], BIN);
Serial.println(snake_custom_char[7], BIN);
lcd.createChar(1, snake_custom_char);
lcd.setCursor(print_x, print_y);
lcd.write((byte)1);
print_x++;
}
print_y++;
print_x = 0;
}
}
I think the reason that this does not work is that the LCD is always referencing that same CGRAM location when it has to print what you want however many times per second. The way I am doing it, whenever a different character is printed (or created in the CGRAM), all character on the LCD referencing that CGRAM location are changed to the new custom character, so in this way, it is impossible to have more than 8 different custom characters printed on the screen at once.
Ok, that was pretty pretty long winded for a relatively simple question, but I just wanted to make sure that you got as much of the information that you might need.
Ok, so finally here is my question again:
Is it possible to print more than 8 different custom characters to the LCD at once with a different method than the one described above or is this simply impossible with my current hardware?
