44780 Display Characters
44780 Display Characters
I'm using a 1x14 LCD display as a trim indicator. I'd like to use the "block" character or ASCII 219 (all dots on in the character block) as the indicator "element". The display is mounted vertically on my trim wheel and the block character will move up or down from neutral (the middle of the display) to indicate nose up or nose down. I can't seem to access the "block" character as listed in the 44780 character datasheet (lower right corner, 1111-1111). I'm looking for any advice on how to code that in the hw_char_display_set_text statement I'm sending to the display. I've tried all the ASCII codes accessible through the keyboard (hold the alt key down, type the ASCII character number on the keyboard number keys to the right, let go). There are other characters to use (like the "|") but the full block looks best. Thanks for any input.
Re: 44780 Display Characters
Hi,
It would appear AM is just using the standard 7 bit ascii 'normal' characters that could be displayed directly via the keyboard, (decimal 0-127), not 'extended' ascii (128-255) , which is understandable.
I have never tested the 44780 with AM - only with Arduino - but, out of interest, there are two roms available for the 44780U .. the A00 and the A02
in the datasheet you have looked at it seems that you are looking at the A00 Japanese rom,
If you look here at page 18 this is the map in the A002 rom for the English / Cyrillic version - note differences.
https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
Also, as the hw_chr_display_set_text in AM appears to need a 'string' input as opposed to a value - (ascii etc). I also can not see how this could be reproduced even you could represent direct characters from the 44780 rom as it is not even in the A02 rom - and, the rom does not directly represent the windows extended ascii character set etc. It would seemingly only be possible if you could send a direct rom map code to the display, or, AM had the facility built in.
Perhaps @Corjan or @JackZ could advise ?
Joe
It would appear AM is just using the standard 7 bit ascii 'normal' characters that could be displayed directly via the keyboard, (decimal 0-127), not 'extended' ascii (128-255) , which is understandable.
I have never tested the 44780 with AM - only with Arduino - but, out of interest, there are two roms available for the 44780U .. the A00 and the A02
in the datasheet you have looked at it seems that you are looking at the A00 Japanese rom,
If you look here at page 18 this is the map in the A002 rom for the English / Cyrillic version - note differences.
https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
Also, as the hw_chr_display_set_text in AM appears to need a 'string' input as opposed to a value - (ascii etc). I also can not see how this could be reproduced even you could represent direct characters from the 44780 rom as it is not even in the A02 rom - and, the rom does not directly represent the windows extended ascii character set etc. It would seemingly only be possible if you could send a direct rom map code to the display, or, AM had the facility built in.
Perhaps @Corjan or @JackZ could advise ?
Joe
Joe. CISSP, MSc.
Re: 44780 Display Characters
Makes sense. Thanks for the input. I thought about the direct rom code but not sure how to get that accomplished through a string.