CFA-635 special characters


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I am feeling kind of stupid right now, because I cannot find the information I need in the CFA-635 datasheet, but I do not see anyone on the 'Net asking my question. Maybe it's in there, and I just don't see it...I don't know.

In any case, the CFA-635 has a command, 0x09: Set LCD Special Character Data, to define the bits for the eight special characters. What I cannot find anywhere is how one uses these special characters. I do not see any mention of this under the 0x1f: Send Data to LCD command.

Is there some special way to specify these characters? Or do they replace eight of the characters defined by the CGROM? If so, which ones?

While we are talking about the CGROM and such...Based on the CGROM chart in the datasheet, and what I see on the screen, the CFA-635 is generating 5x7 characters. The description of the 0x09: Set LCD Special Character Data command says each of the eight data bytes can have a value between 0x00 and 0x3F, which would be six bits. Should that really be 0x1F, rather than 0x3F?

I know that the S6A0073 controller can support 6x8 characters as well as 5x7 ones, and it would probably be possible to shift it to 6x8 mode using the 0x16: Send Command Directly to the LCD Controller command. But if the CGROM is set up for 5x7, I am assuming that one would either get 5x7 characters with more space around them, or hash for the built-in characters. Is this true?

Thanks for your help,

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