Javelin with Hitachi 44780 LCD Screen

AntoineAMOSSE

Hello,

I am working on the Javelin Stamp Starter Kit and Try to display some
characters on a hitachi 44780 LCD Screen. I have downloaded the class
found on this web site link:
http://www.parallax.com/javelin/underdev.asp, but it doesn't work.

Firstly, when I compile the lcdTest.java, there are several errors from
lcdOut method which does not exist. So, I have change this name in
"write(String s)" method but I don't know it is the same.

Has somebody ever work on that screen with Javelin? I am looking for some classes

Regards

Antoine AMOSSE

Peter Verkaik

I fixed those files for you.
Unzip the attachement into folder ...\lib\stamp\peripheral\lcd
Please first remove the 3 files hd44780.java, lcdtest.java and lcd5x10.java
from that folder before unzipping.

regards peter

AntoineAMOSSE

Hello,

Thank you for your speed answer but it does not already work. Can you let me know about your connections.
Your object is declared like that:
HD44780 myLCD = new HD44780(CPU.pin0); // same as BS2p LCD connections

But I don't know what are the right connections. Those I have are the following:

LCD | Javelin Stamp

pin1 (ground) => Ground
pin2 (VDD) => VDD (5VDC)
pin3 (Contrast Voltage) => ground
pin4 (R/S) => CPU.pin3
pin5 (R/W) => CPU.pin2
pin6 ("E" CLK) => CPU.pin0
pin7 (db4) => CPU.pin4
pin8 (db5) => CPU.pin5
pin9 (db6) => CPU.pin6
pin10(db7) => CPU.pin7

Is it good?

Regards

Peter Verkaik

You got the connections right.
If you don't read the LCD ram memory, you can tie R/W to GND.
(otherwise you must make javelin pin 2 low output).
See this document for schematic:
http://www.parallaxinc.com/dl/docs/cols/nv/vol2/col/nv68.pdf

Also, it is preferable to have a pullup/pulldown resistor on the enable line.
Finally, you should use a potmeter to be able to set the lcd contrast.
Otherwise you may not see anything.

regards peter

AntoineAMOSSE

Thank you very much, now it works