View Full Version : LCD Appmod help

01-28-2011, 08:01 PM
Hi everyone, It's my first post.

I recently bought a parallax LCD Appmod to go with my BS Discovery kit (just got through WAM) as I wanted to learn LCD programming without buying too picey Smart Sensors or Stampworks.

I thought that I would find a suitable guide for programming parallel LCD, but even when looking at Stampworks guide or the LCD appmod demo, I still can't get it. I just want to display messages on the display. No custom chars or whatever.

Also, how do you read pushbuttons state? Look like they're on the same inputs as the LCD.

I've read a few things, but It's all about advanced techniques like custom chars and scrolling. Can somebody points me to a ''Basic parallel LCD operation with the LCD Appmod'' manual? I'm using a BS2 with a BOE.

I'm a student in electronics and my end of year project (personal project) will be a robot which uses an LCD display (well, serial, but I got a parallel anyway, so...), so got to learn it!

Please excuse my messy english!


PJ Allen
01-29-2011, 01:05 AM
manual.. attached

01-29-2011, 03:47 AM
Thank you, but that doesn't help me very much. I already read it. Can't understand most of the program. And google doesn't seem to be much help.
Wish I had a 2p24...

01-29-2011, 04:46 PM
Here (attached) is a modified version of the demo software.


I hope it's helpful. The purpose was to make the demo a bit easier to understand by removing the conditional compilation material and just concentrating on how to use the LCD Appmod with the BS2.

As you may know, some of the Stamp modules (2p, 2pe, 2px) have PBASIC commands that let you easily control a parallel LCD like the Appmod. The other Stamp modules do not. The demo software on the Parallax site checks to see which Stamp module you're using, and if it's a 2p, 2pe, or 2px, it uses the special commands. If not, it does things the old-fashioned way. That's great as far as being useful, but it also makes the code considerably more difficult to understand.

The key to using the Appmod is the subroutines at the bottom of this code, particularly these:

They're not particularly transparent, but if you use them in their existing form you should be able to display on the Appmod, and read the state of the buttons.

Oh, and the buttons ARE on the same lines as the LCD. That's why there's this line in the LCD_Get_Buttons subroutine:

LcdDirs = %0000 ' make LCD bus inputs

01-29-2011, 06:36 PM
That was exactly what I was searching! The ''BS-Agnostic'' code confused me.
Thanks you for that. I'll have a look at these subroutines.

jim N8RHQ
01-31-2011, 05:03 AM
Here's a quick demo I wrote for my nephew, hope it helps.