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LCD refresh, how? — Parallax Forums

LCD refresh, how?

ArchiverArchiver Posts: 46,084
edited 2003-10-08 14:55 in General Discussion
Hello,

While displaying a variable temperature on an lcd, when the temp.
decreases, the F remains on the screen from the previous larger
number. If I put the clear screen command at the start of the lcd
code, then the lcd refreshes so fast that it doesn't look nice.
Almost looks like it's flashing.

When it says: 100 F
And the temp decreases, you get: 99 FF
And more: 9 FFF

Does someone know how to solve this??

Thank you,
John

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-10-08 02:48
    Print spaces after your string. e.g. Instead of printing "100F", print "100F
    ". Then when you drop to 99 you won't see "99FF".

    You could also get fancy and use a little math to calculate the proper
    number of spaces and print them in a loop or something.


    >
    Original Message
    > From: cn00728 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=OAEtLWQJamnyE_-MuflHNK_io-2bt3k5UHNmZXe0F1GRvO_MH-EhJnceUF65oOicbj2vuLi7mpwqBg]cn00728@y...[/url
    > Sent: October 7, 2003 6:05 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] LCD refresh, how?
    >
    >
    > Hello,
    >
    > While displaying a variable temperature on an lcd, when the temp.
    > decreases, the F remains on the screen from the previous larger
    > number. If I put the clear screen command at the start of the lcd
    > code, then the lcd refreshes so fast that it doesn't look nice.
    > Almost looks like it's flashing.
    >
    > When it says: 100 F
    > And the temp decreases, you get: 99 FF
    > And more: 9 FFF
    >
    > Does someone know how to solve this??
    >
    > Thank you,
    > John
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the
    > Subject and Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-08 02:49
    Easy - instead of printing "F" after the number, print "F ".
    I've had to do this before when displaying a value. The extra spaces will
    cover up the F that gets left behind from the larger number.

    73 de KG6SGY



    Original Message
    From: "cn00728" <cn00728@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, October 07, 2003 6:05 PM
    Subject: [noparse][[/noparse]basicstamps] LCD refresh, how?


    > Hello,
    >
    > While displaying a variable temperature on an lcd, when the temp.
    > decreases, the F remains on the screen from the previous larger
    > number. If I put the clear screen command at the start of the lcd
    > code, then the lcd refreshes so fast that it doesn't look nice.
    > Almost looks like it's flashing.
    >
    > When it says: 100 F
    > And the temp decreases, you get: 99 FF
    > And more: 9 FFF
    >
    > Does someone know how to solve this??
    >
    > Thank you,
    > John
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-08 14:55
    John-

    I'd use a 5-byte wide array on the Stamp and a constant beginning
    address of choice on the LCD. To refresh the display:

    - Fill the array with blanks

    - Overwrite the (blank) array with the desired text

    - Send set display address command to LCD

    - Write all 5 array bytes to the LCD


    Regards,

    Steve


    On 8 Oct 03 at 1:05, cn00728 wrote:

    > Hello,
    >
    > While displaying a variable temperature on an lcd, when the temp.
    > decreases, the F remains on the screen from the previous larger
    > number. If I put the clear screen command at the start of the lcd
    > code, then the lcd refreshes so fast that it doesn't look nice.
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