Support for HD44780 through Serial


New member
Firstly I'd liked to say that CrystalControl rocks!

However, I desparately need support for parallel HD44780 displays through the serial port in CrystalControl.
I am running a blue backlit 20x2 Crystalfontz LCD with a PIC and need I CrystalControl to send HD44780 format commands for this size screen to a COM port instead of the LPT port.

I have already tried converting the 'Set Cursor Position' commands CrystalControl uses to control a 632/634 display into 'Set DDRAM address' commands for the HD44780 using the PIC. It does display the text but it's still not in the right place.
I wonder if a future option could be put into CrystalControl for serially controlled HD44780 displays using cursor homing and shifting instead of cursor positioning???

Or, could someone please help me with the PIC code as I've only been programming in assembly for a few weeks! :confused:
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New member
I have a little thing that i got from synopsoid1 (think it's spelt that way). It is a circuit board design and pic code (C) that makes a "backpack" out of a PIC16F84. He told me he wasn't finished with the code and some other things but if you like i will send it to you.


New member
Hi PaNiC,

If you could send me the files, that would be great. Many thanks in advance.
I actually need to know the exact commands to send to an HD44780 to set the cursor position. I assume by looking at the datasheets and on the net that you just send 80 (hex) + the cursor position in a single command. Does anyone have any ideas.... anyone ;)