LK204-25 I2C Troubles

[gbtsdd]

Hello,

I am using a Netburner MOD5270 to communicate to an LK204-25 LCD via I2C. I have tested the screen with a number of commands successfully (and with no side effects) including cursor settings (position, type), medium numbers, vertical/horizontal graphs, etc.

When sending large numbers, a normal sized character appears after the large number (picture). This character seems to typically be a 5x5 pixel dot, although a few times it showed up as an omega (ω) or a calligraphy f. The character that is displayed does not change once the LCD is running. If this is in fact intended, how are large numbers rewritten into custom character banks (IE, how can I get rid of the periods)?

I also cannot read the module and version numbers (both return zero). Is there a common pitfall with these commands that I am encountering?

As a complaint about the site, the forum registration CAPTCHA is atrocious; it took me around 4 tries to get it correct and I'm not sight impaired.

[Raquel]

Hello gbtsdd,

Thanks for your post.

I wonder if maybe you are sending extra characters that the display draws on the screen. Large numbers are not intended to have these extra characters.

I suggest that you check with a scope what you actually send to the display, and see maybe, if you are sending these extra characters.

As per reading data back from the display, please see this App Note, question #5.

I hope these help.

Thanks and Best Regards,

[gbtsdd]

Hey Raquel,

As per reading data back from the display, please see this App Note, question #5.

This did the trick, I can now read version and module numbers. The version (254 / 54) is showing up as 0x60, which is not listed in the Technical Manual (Rev 2.0). By the style of the versions listed in the manual this screen would be a version 6.0?

I will investigate the other problems with a scope as you suggested. Thanks for the response!

[Raquel]

Yes, v6.0 for 0x60 reply from the display.
Glad to hear things are working.

Best Regards,