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Max The Magnificent
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Re: Five buttons?
Max The Magnificent   1/15/2014 11:08:42 AM
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@David: I have always liked the 4 button interface - Next / Last / Select / Return.

You can of course use thre buttons on the Adafruit LCD shield to do anything you want -- I quite like the Up, Down, Left, Right, Select -- although at the moment I'm only using Up and Down ...

Max The Magnificent
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Re: Five buttons?
Max The Magnificent   1/15/2014 11:06:25 AM
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@DeeCee430: Five buttons?  Who needs five buttons when one will do?!

This is a classic story of engineering working aroudn changing specifications -- thanks for sharing it here.

Max The Magnificent
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Re: Write Only Memory
Max The Magnificent   1/15/2014 11:04:28 AM
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@Antedeluvian: Do you know if the software support provided by Adafruit treats the LCD as a write only memory?

I never even thought of this. I haven't seen any commands that allow you to read back from the LCD (it would be nice to be able to read the position of the cursor, for example).

It woudl be useful to be able to do this -- you might want to try posting a question on the Adafruit Forums

And I think it would be great if you were to recycle that MCC bblog -- just send it to me and I'll post it

 

antedeluvian
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Re: Five buttons?
antedeluvian   1/14/2014 8:56:13 PM
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David

Next/last step through the menu

Return goes back to the last level or quitw the menu

Yeah, but the menus themselves are the crux of the matter. I developed an approach which I ended up publishing as an aritcle for Circuit Cellar "Hierarchical Menus in Embedded Systems" in the Nov 2003 (#160) issue. (Circuit Cellar's business model is to charge for downloads. That far back requires that you download the whole issue.) It is built in C, butit an be implemented in any language.

That project is where I developed the appreciation of making sure the display was working as I mentioned in my response to Max a few reponses below.

 

David Ashton
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Re: Five buttons?
David Ashton   1/14/2014 7:57:20 PM
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I think for a small LCD the 5 buttons are a bit of over kill, but I have always liked the 4 button interface - Next / Last / Select / Return.

Select opens the meny or selects the option you are on

Next/last step through the menu

Return goes back to the last level or quits the menu

One button is ok, but there's usually a bit of a learning curve associalted with them.  Fine once you get used to them though.

DeeCee430
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Five buttons?
DeeCee430   1/14/2014 7:41:41 PM
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Five buttons?  Who needs five buttons when one will do?!

The LCD Shield reminds me of a project I worked on 15-20 years ago.  It was to be a hurredly-built one-off instrument for another department of our company.  It's LCD (from Seetron) had 4 rows of 20 characters and was controlled by a serial port (RS-232).  The original specifications for the instrument only required a stop/start function, so I only designed in a single push-button switch (debounced in software), with the measurement results and current function (start vs. stop) of the button displayed on the LCD.

But after most of the hardware had already been built, further discussions with the internal customer indicated a much more sophisticated user interface was required.  How to accomplish this without adding more keys, which would require completely rebuilding the front panel and lots of modifications to the circuit board?

The solution was to implement a menu system, with a short keypress highlighting the next menu line on the LCD (and wrapping around from the bottom line to the top line), and a long keypress selecting the menu item, to either perform a function or display a lower-level menu.  The 4th line was always a "go back one level" function.

The user waited until after I got this working before letting me know he also needed to be able to enter numeric values!  No problem.  I created a numeric entry screen displaying the digits 0 to 9, decimal point, plus/minus signs, and if I remember correctly, a left-arrow for backspacing, and "OK" to indicate the entry was complete.  Short keypresses cycled through all these symbols and a long keypress selected the symbol.  One of the lines displayed the current value being editted.

It actually worked quite well, even if I wouldn't have designed it this way if I had known the complete requirements up front.



antedeluvian
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Write Only Memory
antedeluvian   1/14/2014 5:36:50 PM
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Max

Do you know if the software support provided by Adafruit treats the LCD as a write only memory? One of my favourite soapboxes is this issue of not checking to see if the LCD is in fact running. I did a blog on it on MCC- maybe I should recycle it.

Max The Magnificent
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Re: parent/child project?
Max The Magnificent   1/14/2014 4:47:57 PM
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@DCH0: "this would make a great father-son project" repeats stereotypes.  I do not mean to be politically correct, but daughters do very well with these.

You are of course correct -- in fact the main reason I said this is that another reader had contacted me following my Creating a Bodacious Bensonfruit Arduino Mega Proto Screwshield PCB and said that he was working on an Arduino project with his son, and this has stuck in my mind.

I should have said "Parent-Child" project -- I stand corrected I will now take myself outside and administer a severe spanking :-)

DCH0
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parent/child project?
DCH0   1/14/2014 4:09:29 PM
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"this would make a great father-son project" repeats stereotypes.  I do not mean to be politically correct, but daughters do very well with these.

Max The Magnificent
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Using the backlit colors
Max The Magnificent   1/14/2014 12:52:47 PM
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One question you may have regards the value of being able to modify the display's background color.

As my code becomes more complex, I may end up checking certain values to make sure they stay within a certain range -- I can see myself using different background colors to alert me as to overall status, like "Red" could indicate something that requires my immediate attention.



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