Q: Re LCD Display Supplied with Inex-1000 Board
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Hi All,
Someone who's into the LCD that Parallax supplies with the Inex-1000
board
should be able to answer this:
Background:
The LCD module is a 1 x 16, with no backpack, with a controller chip SED1278F0a
whose mfgr logo looks like <twin peaks (^^) + JAPAN. (who's chip is it?)
The display appears to work just like a Hitachi HD44780. (Is it a clone?)
It's connected via the Inex board in the "standard" way:
as suggested in the sample "LCD Experiment" code in the instruction
sheet that
came with the Inex. LCD D4-D7,RS,E to Stamp P0-P3,P4,P5 respectively,
LCD R/W grounded. Some old N&V articles also show the Hitachi connected
identically.
(This experiment's uncommented code is the *only* hint as to how the
LCD works. Parallax should have at least included a mfgr spec sheet for the
display controller chip. soapbox off)
Question #1: When I send in the first 8 characters (from left),
everything works fine,
but before sending the 9th character, I gotta send a command $C0 or
these next 8
characters don't make it to the display. Why? What's a command $C0?
(the "LCD Experiment" does this, but offers not a clue why...)
Question #2: I can't get the scroll display left command ($18) to work.
(haven't even tried scroll right [noparse]:)[/noparse]
When I scroll left, it seems to scroll the first 8 chars and the last 8 chars
independently and simultaneously, putting a blank in character 7 as well
as character 15.
eg:
Before scroll left: Display shows "ABCDEFGHIJKLMNOP"
After scroll left: Display shows "BCDEFGH JKLMNOP "
One more scroll left gives: "CDEFGH KLMNOP "
What I really wanted: "BCDEFGHIJKLMNOP "
and then of course: "CDEFGHIJKLMNOP "
Why do I feel these 2 questions are related?
I read somewhere that some 1 x 8 displays are configured as 2 "lines" of
8 chars.
Could this be one of them? If so, How do I scroll left properly?
Thanks to the collective for any help provided!
'73
Ken N2TIA
Someone who's into the LCD that Parallax supplies with the Inex-1000
board
should be able to answer this:
Background:
The LCD module is a 1 x 16, with no backpack, with a controller chip SED1278F0a
whose mfgr logo looks like <twin peaks (^^) + JAPAN. (who's chip is it?)
The display appears to work just like a Hitachi HD44780. (Is it a clone?)
It's connected via the Inex board in the "standard" way:
as suggested in the sample "LCD Experiment" code in the instruction
sheet that
came with the Inex. LCD D4-D7,RS,E to Stamp P0-P3,P4,P5 respectively,
LCD R/W grounded. Some old N&V articles also show the Hitachi connected
identically.
(This experiment's uncommented code is the *only* hint as to how the
LCD works. Parallax should have at least included a mfgr spec sheet for the
display controller chip. soapbox off)
Question #1: When I send in the first 8 characters (from left),
everything works fine,
but before sending the 9th character, I gotta send a command $C0 or
these next 8
characters don't make it to the display. Why? What's a command $C0?
(the "LCD Experiment" does this, but offers not a clue why...)
Question #2: I can't get the scroll display left command ($18) to work.
(haven't even tried scroll right [noparse]:)[/noparse]
When I scroll left, it seems to scroll the first 8 chars and the last 8 chars
independently and simultaneously, putting a blank in character 7 as well
as character 15.
eg:
Before scroll left: Display shows "ABCDEFGHIJKLMNOP"
After scroll left: Display shows "BCDEFGH JKLMNOP "
One more scroll left gives: "CDEFGH KLMNOP "
What I really wanted: "BCDEFGHIJKLMNOP "
and then of course: "CDEFGHIJKLMNOP "
Why do I feel these 2 questions are related?
I read somewhere that some 1 x 8 displays are configured as 2 "lines" of
8 chars.
Could this be one of them? If so, How do I scroll left properly?
Thanks to the collective for any help provided!
'73
Ken N2TIA
Comments
>Hi All,
>
>Someone who's into the LCD that Parallax supplies with the Inex-1000
>board should be able to answer this:
>Sorry, don't have one : (
>Background:
>The LCD module is a 1 x 16, with no backpack, with a controller chip
>SED1278F0a whose mfgr logo looks like <twin peaks (^^) + JAPAN. (who's
>chip is it?)
>Epson
>The display appears to work just like a Hitachi HD44780. (Is it a clone?)
>In many ways, yes, and in other ways not.
Here is the data sheet: [noparse][[/noparse] http://eko.epson.co.kr/pdf/sed1278.pdf ]
>It's connected via the Inex board in the "standard" way:
>as suggested in the sample "LCD Experiment" code in the instruction
>sheet that
>came with the Inex. LCD D4-D7,RS,E to Stamp P0-P3,P4,P5 respectively,
>LCD R/W grounded. Some old N&V articles also show the Hitachi connected
>identically.
>(This experiment's uncommented code is the *only* hint as to how the
>LCD works. Parallax should have at least included a mfgr spec sheet for
>the display controller chip. soapbox off)
>
>Question #1: When I send in the first 8 characters (from left),
>everything works fine,
>but before sending the 9th character, I gotta send a command $C0 or
>these next 8
>characters don't make it to the display. Why? What's a command $C0?
>(the "LCD Experiment" does this, but offers not a clue why...)
It's a Write Data to CGRAM Command, but check the data sheet for details.
>Question #2: I can't get the scroll display left command ($18) to work.
>(haven't even tried scroll right [noparse]:)[/noparse]
>When I scroll left, it seems to scroll the first 8 chars and the last 8 chars
>independently and simultaneously, putting a blank in character 7 as well
>as character 15.
>eg:
>Before scroll left: Display shows "ABCDEFGHIJKLMNOP"
>After scroll left: Display shows "BCDEFGH JKLMNOP "
>One more scroll left gives: "CDEFGH KLMNOP "
>What I really wanted: "BCDEFGHIJKLMNOP "
>and then of course: "CDEFGHIJKLMNOP "
If you are NOT getting to the "next" RAM address properly, odd things can
happen. Additionally, I glanced at the data sheet, and it appears some BIT
settings may be involved.
>Why do I feel these 2 questions are related? Because they PROBABLY are
>related : )
>I read somewhere that some 1 x 8 displays are configured as 2 "lines" of
>8 chars.
>Could this be one of them? If so, How do I scroll left properly?
>1 x 80 = 2 x 40, 1 x 32 = 2 x 16, so I'd guess 1 x 16 = 2 x 8 <shrug>
>Thanks to the collective for any help provided!
>Time will tell on THAT <g>
>'73
>Ken N2TIA
Regards,
Bruce Bates