Store Custom Characters for LCD in EEPROM?

[wdmagic]

henrik, I was reading an article about someone that uses about 20 characters, he loads the character to lcd memory then send the display command, Im not looking to load more than 8 at a time or display more than that, just to have the choice of what to load. So if I want to load images for batteries with levels 1-8, reload new image batch, and then refresh screen with images for 8 temprature pics, etc... I figured I could do a 8 Character groups, Batteries, Temp Guages, Smileys, Misc symbols, Etc... if I did them 8 char x 4 groups that gives me 32 characters to call from. and it should be easier to handle memory addresses.

[HenrikOlsson]

Hi Chris,
Sure, that should work.
Yes, looking at the block diagram in the HD44780 datasheet it does seem like you COULD actually load 8 chars to CGRAM, display them (which writes them to DDRAM) and then overwrite the CGRAM with 8 new ones, display those and so on.
Anyway, if there's no need for more than 8 at a time then you're all set.

Keep us posted!
/Henrik.

[spcw1234]

Hi Chris,
Sure, that should work.
Yes, looking at the block diagram in the HD44780 datasheet it does seem like you COULD actually load 8 chars to CGRAM, display them (which writes them to DDRAM) and then overwrite the CGRAM with 8 new ones, display those and so on.
Anyway, if there's no need for more than 8 at a time then you're all set.

Keep us posted!
/Henrik.

My experience with this is when you try to load new characters into the CGRAM it overwrites the ones currently being displayed. I have not been successful displaying more than 8 characters, or even displaying 8 and loading more into CGRAM. Some displays do have slightly different features so it may be possible on the right display.