Serial/USB interface for HD44780 using AT89c2051

lui · Post by **lui** » March 29th, 2007, 4:02 am

I created this protocol converter more than 1 year ago. It can do only the basic character display functions. However, I had not yet done the customized character part. So, big characters, bars would not be supported.

The design was based on the CrystalFontz protocol. I had found out the way to control the backlight brightness & contrast and may continue my development work probably in Q2/07.

http://www.hkepc.com/bbs/viewthread.php?tid=502199

lui · Post by **lui** » March 29th, 2007, 4:12 am

Can anybody gives me some information how to send back push-button(s) information back to LCD Smartie using Crystal Fontz Protocol via COM port / USB port?

Thanks a lot.

Post by **limbo** » March 29th, 2007, 9:04 pm

Is there any english version available of the site info?

Post by **mattcro** » March 30th, 2007, 11:50 am

I guess you have looked at the data sheets and user manuals for the CrystalFontz modules. Look at one that has a keypad, and you'll see info on how to read keypresses from the module. You can probably use this protocol info to help you write code for your project.

I don't know much about the CrystalFontz modules as I've only used Matrix Orbital (I made a converter based on MO protocol), so I'm not sure exactly how Smartie gets the keypress info - there are 2 methods I think: 1 where the module just transmits keypress messages as they happen, and 1 where the host must poll the LCD.

Hope that helps. Have a good read of the documentation and look at the demo program source (and perhaps Smartie driver source).