MTC Display

[bill]

Hello,

few times ago, i build a midimon http://ucapps.de/midimon.html with it's MTC display (very nice)

Now, i'm interested in driving the Display module, with C code.

But, I dont know how to start (i still dont understand very well the mutliplexing stuff), so i ask you, as usual ;)

I think it could kick ass to see, pattern position, tempo, CC,'s, Hex values etc, on those nice glowing numbers :)

[jdelgoulet]

Hi all !

Just to let you know that the commander.de stite is un reachable but ... I've been hunting and YES !!! the sdcc installer (thanks god ! that's really cool) is available here for all OSX super Star Users !!! :

http://www.1710.co.uk/picosx/Resources/

Thanks you very for all those installers !!!

Jules - Toulouse, France.

[bill]

Hem, i reply to myslelf, not bcause i'm stupid but because i have some clues, and i dont want you waste your time :

I found many interesting informations in the leddigits.inc file, from the midimonV2 application :)

I think the most important was :

;; --------------------------------------------------------------------------
;;  FUNCTION: LEDDIGITS_Update
;;  DESCRIPTION: This function should be called periodically by 
;;  USER_SR_Service_Prepare before the DOUT registers will be updated
;;  from MIOS
;; .....
;; --------------------------------------------------------------------------
LEDDIGITS_Update	
;; increment LED digit counter, wrap at 4
	;; (0, 1, 2, 3, 0, 1, 2, ...)
	SET_BSR	LEDDIGITS_CTR		; (use bank mechanism so that the registers can be located at addresses >= 0x80)
	incf	LEDDIGITS_CTR, W, BANKED
	andlw	0x03
	movwf	LEDDIGITS_CTR, BANKED

	;; get shift register pattern for the select line:
	;;  LED digit 0 and 4 -> b'10001000'
	;;  LED digit 1 and 5 -> b'01000100'
	;;  LED digit 2 and 6 -> b'00100010'
	;;  LED digit 3 and 7 -> b'00010001'

I'm on the way to do it working the same way, but without asm.

[audiocommander]

Hi Bill,

as I understood, the main trick is to wire the LEDs correctly (I think a sample can be found with the LED-Rings wiring PDF). Then you need kind of a matrix array for each figure you want to display... this matrix is then switched line-by-line...

sorry if I'm so unconcrete... I'm very short in time these days, I'll watch this thread, maybe I can contribute more details when I get my LED-meters working :)

Cheers,

Michael

@jdelgoulet: thanks for your kind words :)

although this is a bit off-topic, just for the record, my site has never been down: http://www.audiocommander.de/blog/?p=48 and Ben (http://www.1710.co.uk/picosx/) had only temporary troubles 'cause the server got struck by a lightning  :o

[bill]

Hello,

the main trick is to wire the LEDs correctly

I have this part done (i allready have my midimon+led display working perfectly)

I tried this simple code, with no success, anyone can help me ?

(i thought) this code should send the pattern 0x7f to every led-chars, but they are all off :(

any idea ?

unsigned char led_c=0;//led counter
const char led_b[8] = {	0,0,0,0,0,0,0,0,};//led buffer
const char led_sr[4] = { 0x88,0x44,0x22,0x11,};//shift register patterns
/*
	;;  LED digit 0 and 4 -> b'10001000' 0x88
	;;  LED digit 1 and 5 -> b'01000100' 0x44
	;;  LED digit 2 and 6 -> b'00100010' 0x22
	;;  LED digit 3 and 7 -> b'00010001' 0x11
*/
void SR_Service_Prepare(void) __wparam
{
	//LEDDIGITS_Update
	MIOS_DOUT_SRSet(1,led_sr[led_c]);//char selection (0123)
	MIOS_DOUT_SRSet(0,0x7f);//first 4 digits (test pattern)
	MIOS_DOUT_SRSet(2,0x7f);//next 4 digits (test pattern)
	led_c++;
	if(led_c>3)led_c=0;
}

[bill]

STupid me !!!  ;D

I forget to "init MIOS_SRIO_NumberSet();"

It's working perfectly  8)

Now, i'm pretty interested on doing the algorythm to fill the led_buffer (dec2led and hex2led)

then "how to drive 16 chars with another 74hc595"  :)