LCD

Marc91

Hello everybody.

I have a Propeller 40 PIN DIP CHIP and I'm trying to use a LCD screen 2x16 HD44740.
I don't really know how does it works. So I've tried to follow instructions on the internet, but it doesn't works.

Here is the links between the outputs of my LCD screen :
1 : GND
2 : +5V
3 : link to GND with 3K resistor
4 : P3
5 : P2
6 : P0
7,8,9,10 : GND
11 : P4
12 : P5
13 : P6
14 : P7
15 : +5V
16 : GND
I've followed the picture here : http://www.parallax.com/Portals/0/Downloads/docs/prod/audiovis/lcd2x16par.pdf


Here is the soft I'm using :


CON
_clkmode = xtal1 + pll16x ' Feedback and PLL multiplier
_xinfreq = 5_000_000 ' External oscillator = 5 MHz

PUB ButtonBlinkSpeed
dira[0..10]:=1
waitcnt(clkfreq/100 + cnt)

repeat
outa[1..10]:=1
outa[0]:=1
waitcnt(clkfreq/100 + cnt)
outa[0]:=0
waitcnt(clkfreq/100 + cnt)
outa[0]:=1


I guess my soft isn't working, because I don't know what each output is doing...
Could anyone help me about the software part ?
I'd like (first) to write anything on the screen.
Marc

CannibalRobotics

Over in the obex there is a BS2 function set for the prop.
Might try that to get a leg up on the initialization code, those LCD's take several configuration bytes before you can get them up and running.
There are also a bunch of HD44xxx objects. Most of those will probably work with some minor modifications.
Jim-

JonnyMac

This will help: http://www.parallax.com/Portals/0/Downloads/docs/cols/nv/prop/col/nvp2.pdf

I've also attached the latest version of my 4-bit LCD driver.