This page will contain the information about the combined lcd/button matrix
[[http://www.midibox.org/forum/index.php?topic=7087.0|forum topic]]<sup>uCApps</sup>

right now I'm using a modified version of the sm_simple C example\\
this code will be rewritten to make it more coherent

modifications to [[http://www.ucapps.de/mios/sm_example1_v2.zip|scan matrix example]] <sup>uCApps</sup>\\

==== Hardware ====
[[http://users.skynet.be/sky92755/DSEQ32_DOUT.pdf|DOUT wiring]]\\
\\
[[http://users.skynet.be/sky92755/DSEQ32_DIN.pdf|DIN wiring]]\\

//*note: schematics not finished!//\\
==== Software ====
in main.c:\\

<code>
...
//second shiftregister drives the leds
#define LEDOUT 1
...
void LM_SetRow(){
	MIOS_DOUT_SRSet(LEDOUT,ledtest[sm_col]);
}

/////////////////////////////////////////////////////////////////////////////
// This function is called by MIOS before the shift register are loaded
/////////////////////////////////////////////////////////////////////////////
void SR_Service_Prepare(void) __wparam
{
  // call the Scan Matrix Driver
  SM_PrepareCol();
  // call the Led Matrix Driver
  LM_SetRow();
}
...
</code>
\\
in sm_simple.asm:
<code>


...
	global	_sm_button_column
	global	_sm_button_row
	global	_sm_button_value
	global  _sm_col

	;; import lables
	extern	_SM_NotifyToggle

; ==========================================================================

accessram		udata		; (no access ram required, these variables can be located anywhere)

_sm_button_column	res	1	; exported to C, therefore an "_" has been added
_sm_button_row		res	1
_sm_button_value	res	1
_sm_col				res 1

...

SM_PrepareCol
	;; select next DOUT register

	;; (current column + 1) & 0x07
	SET_BSR	sm_selected_column
	incf	sm_selected_column, W, BANKED	; (* see note below)
	andlw	0x07
	;_sm_col is used by LM_SetRow()
	movwf	_sm_col
	call	MIOS_HLP_GetBitANDMask	; (inverted 1 of 8 code)
...
</code>
\\
and finally in sm_simple.h:
<code>

...
extern unsigned char sm_button_value;
extern unsigned char sm_col;
...
</code>

==== Appendum ====
To avoid flickering leds when pushing a button 
the MIOS button debouncing should be turned off!!

Due to the setup of the SRIO driver the debounce algoritm
also delays the DOUT chain when a DIN event is being debounced.
So when a button is pushed the led update frequency is reduced,
the higher the debounce value, the lower the update frequency.

According to this post TK will fix this in a future MIOS release:
>This is something what I'm planning to solve in one of the next MIOS versions - currently the same SR scanning routine is used for DIN and DOUT registers, which means, >when the DINs are temporary disabled due to the cheap debouncing method, the DOUT registers won't be updated.
\\
>The solution is to add a second scan routine which only services the DOUTs so long the debouncing delay is active.
\\

In the meantime THIS ISSUE IS SOLVED WITH MIOS1.9c!!!
== Workaround ==
To turn the debouncing off, set
<code>
#define DIN_DEBOUNCE_VALUE    0
</code>


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