HD44780 Set Cursor Position Problem

If you can display char's and everything I don't the timing is the problem.

Are you sure the LCD is good? Do you have a spare you could try? Be a real irritation to find out the LCD has a bad char in the second row, 1st position!

Tim

I know the LCD itself is good as I now have a workaround: I notice that if you print 40 characters on the first line you wrap and start on the second row. So I can get to the second row by sending 24 padding characters after filling row 1. Not entirely satisfactory but it'll have to do. Seems bizarre I can get every function to work but one! I did have a hunch that maybe I was accidentally masking the top bit of the instruction in my code (as every other instruction I use

Did you init it to 2 line mode when you set it up? If you don't do a Function Set command the default is 8 bit interface, 1 line, 5x8 characters. Single line mode is 80 bytes linear addressing. Two line mode splits the addressing to line 1 at offset 0, and line 2 starting at offset x'40'

That sounds exactly like what I must be doing wrong. But how do I set to two line mode? I can't see anything about 2 line mode in the hd44780 docs I can find on the web.

Look for the Function Set command 001DNFxx D - interface data length 1 = 8 bit, 0 = 4 bit N - number of lines 1 = 2 lines, 0 = 1 line F - font 1 = 5x10, 0 = 5x8 xx - don't care

Default is 00100000

you want 00110000 (0x30)

This doesn't seem quite right. To get two line mode I need N=1. And I'm not sure if D should be 0 or 1. Anyway, 0x20, 0x28, 0x30 and 0x38 all fail to make the command to write to line 2 work. Looks like I'm just going to have to go with my workaround of writing padding characters.