Button assignment

[aaronik19]

Dear All. Hope everyone is ok. I have an Lcd 20x4 and 5 buttons and i would like to make a menu (with pages). The buttons are Up, Down, Left, Right and Enter. Now the duty of every button from one page to another is not the same. Example on page 1 the duty of button Up is to scroll up from one line to another and of button Down is to scroll down from one line to another.

On page 2 the Up button is used to increment a typical variable assigned. Can someone please show me a principle of code because i got confused. To alter from one page to another is ok but the button assignment from one page to another - i have no idea and i really wish to understand it.

[Mike Walne]

It's simpler to use only 3 buttons.

Your text for a page or up/down is on the top line of the LCD.

Each button is equally spaced below the bottom line.

The text above each button indicates its function.


Before programming play at computers and work out the paths through the code.
When you get really clever you can include a time out to prevent lockup.

Mike

[aaronik19]

Thanks for the reply but i did not understand what you are saying...sorry

[Mike Walne]

We've met before and I still have no intention of writing code for you.

Maybe this will help.

1st line LCD___________Time setting 12:45
2nd line LCD ___________UP__DN__ENTER

Your three buttons line up under UP/DN/ENTER

It's a Time setting example, current time shows 12:45 with the 4 flashing to show it is being set.

Pressing UP increases 4 to 5.
Pressing DN decreases 4 to 3.
Pressing ENTER sets tens of minutes to 4 and moves on to 1's of hours.
Pressing ENTER twice more either returns to where you were before, or on to setting, day of week, month, day of month, year etc.
It's your program and it does what YOU want it to, NOT what I want it to.

Like I said before play at computers, work out what you want to do in pseudo code, THEN proceed to programming.
You don't do it all at once, start with a part of the code, write it, then test it 'til it begs for mercy.

Mike

PS If you don't like pseudo code draw a flowchart diagram of the pathways through your code.

[temtronic]

If you're really 'frugal' you can do it with just ONE button...

What you want can easily be done with the 'CASE' function.
First you need to 'see' which 'button' is pressed, hopefully from an ISR.
Then decode which button
Then use the 'case' function to direct the PIC to 'do something based upon which button was pressed'
Then in the 'level' or 'page' , you repeat ...

You will need some kind of 'timed' input though.

[aaronik19]

Thanks for your replies. But my query is that my five buttons have different tasks for every page. How i can assign different tasks of these buttons according to the page/screen. I do not want codes...i want just ideas or discussion

[Ttelmah]

You just assign them different tasks....
You have the keys returning the same numeric code, and then in the
program for each page do the task required.

[temtronic]

from the CCS C manual......