Char array = screen content

MIOS programming (C)
1

Hi all,

I’d like to have some realtime messages (+ why not char animations) appear briefly on the screen, so that when they dissapear, the content that was initially displayed on the screen (overwritten by the message) gets back. So I had the idea to develop some kind of “generic” function that would do MIOS_LCD_CursorSet + MIOS_LCD_PrintCString + eventually MIOS_LCD_PrintBCD3 for instance if an int is also passed as a parameter, well you got the idea  :wink:

In the meanwhile, this function could store a copy of what’s been written on the screen (typically a screen dump), so that it can easily refresh original screen when I want to get rid properly of that realtime messages. The problem is it seems impossible to do this without the use of string functions + other C functions (like itoa to display the number).

Does any of you already worked on that subject ?

2

you can simply use

[tt]MIOS_LCD_MessageStart()[/tt]

:wink:

Cheers,

Michael

3

Hey why not  :smiley: ;D but I could never understand the meaning of that function …  ::slight_smile:

Tried it a few times but could never get the written msg to dissapear …  ???

  • what’s the use of MessageStop() ?

Does that code has to be in a specific location within code lines ?

Thanks anyway I’ll give it a try asap !

4

Okay, I’ve tested the function a little deeper than the last time  :wink:

As far as I can see, I’ve two remarks :

  • You must have the entire LCD content written previously (I mean over every single location on the LCD), otherwise the chars generated with MessageStart( ) will not dissapear  ???

  • If you try to deal with counters & cycles to have a nice animation (lets say I want to have an animated worm running on the screen  ;D (good old times)) I can’t say for instance “MIOS_LCD_MessageStart(50);” for each char because it doesn’t care about your counters : all the chars vanish at the same time … (but perhaps have I done something wrong ?)

What’s the use of MessageStop( ) ?

Thank you guys

5

Hi Olivier,

I just noticed that the description in the function overview is a bit misleading.

in principle it’s very (very) simple:

You should call this code not from within the LCD_Tick() routine, but from somewhere else - though of course you can call it from LCD_Tick(), but the point is:

MIOS_LCD_Message_Start() does nothing but preventing MIOS_LCD_Tick() from being called for the given amount of time.

So the use of MessageStop() gets pretty clear; you can immediately abort the message if the delay is still active, so that Tick() is going to be called again. In both cases MIOS_LCD_Init() is called before continuing the Ticks.

As I said, very simple:

MIOS_LCD_MessageStart

C_DECLARATION void MIOS_LCD_MessageStart(unsigned char delay)

DESCRIPTION a replacement for MIOS_LCD_PrintMessage which allows to start a message without calling “MIOS_LCD_PrintString”

C_IN message delay in <delay>

C_OUT -

C_EXAMPLE

  // print message on LCD for 2 seconds

  MIOS_LCD_CursorSet(0x00 + 0);

  MIOS_LCD_PrintCString("Pot value: ");

  MIOS_LCD_PrintHex2(MIOS_AIN_Pin7bitGet(0));

  MIOS_LCD_MessageStart(255);

So, it would help you in the question you asked first, cause you don’t need to care about what was previously on the screen.

By using the delay within a custom timer routine, I think there should also be nice (simple) animations possible. But remember that you have to use your own timer, 'cause StartMessage prevents the LCD_Tick() routine :wink:

Cheers,

Michael

6

Thank you for that clear explanations !!

;D 8)

Now it’s my turn to play  :smiley:

See you guyz