Help LCD with 2 wire Connect (Idea)

[Art]

Care to elaborate to a point where your post makes sense?

[NavMicroSystems]

As Art already said:

If you are expecting any help be as precise as you can on your request.

If you can't (or don't want to) giv more details:
PLEASE DO NOT POST
in this category

[jetpr]

I need to made a Displays Box with Include 4x16 LCD Char and 4 Buttons
But I going to use only 4 wire 1 Power, 2 Serial LCD, 3 Ground and 4 for the 4 push Buttons

Is some one have don this.

[NavMicroSystems]

jetpr,

if one of the four pins that are available is an analog input this shouldn't be much of a problem.

A few resistors setup as R/2R Network give an excellent DAC.

[sougata]

Hi,

You should be using one having hardware USART. What is the distance that you would be hooking upto ? Using a DAC / ADC combination to sense four buttons may then be difficult. I personally tend to use the 18F452 because of its speed. You don't miss characters due to overflow. Keep in mind the code overhead in your main processor. If you mention your application in details may be one of my previous code will suite your app.

Regards

Sougata

[jetpr]

Ken i Use 4 Resistors of R1=10k,R2=20K,R3=30K,R4=40 AND USE THE
ADCIN VoltChannel, Voltage

IF Voltage > XXX THEN THIS IS = BUTTON ONE AND SO ON

[sougata]

What if the user presses all the four or any combination of switches simultaneously. Although this can be accomodated in the algo. You still did not reply to my prevoius query. BTW without anymore details or positive outcome I am out of this thread.

[NavMicroSystems]

Ken i Use 4 Resistors of R1=10k,R2=20K,R3=30K,R4=40 AND USE THE
ADCIN VoltChannel, Voltage

IF Voltage > XXX THEN THIS IS = BUTTON ONE AND SO ON

In principle yes.

There are many different ways to set this up,
it depends on what type of buttons you have.
if they have NO + NC contacts then you could setup a real R2R Network
this would allow to detect any combination of keys pressed.
(more than one at a time)

The simplest (with primitive NO-pushbuttons) would be:
5 resistors all of the same value (say 2k2, or 4k7) in series.
(but if more than one key is pressed at a time you will only detect the one pressed closest to the input.)