MB808 how connecting BPM Digit on DOUT

MIDIbox SEQ
1

i have bought some led Digit display like this

http://www.lenoo.com/ec99/myyp090083/GoodsDescr.asp?category_id=51&parent_id=0&prod_id=2066

 

I wanted to konw how connecting The 3 DIGT on the DOUT.

2

The default configuration is:

 

; === BPM digits ===
;
; set to 1 or 2 to enable the 3 optional BPM digits
; 0: BPM digits disabled
; 1: digits with common cathode
; 2: digits with common anode
#define DEFAULT_BPM_DIGITS_ENABLED 0
;
; define the shift register to which the segments are connected (0=disabled)
#define DEFAULT_BPM_DIGITS_SEGMENTS 5
; define the shift register to which the common pins (cathodes or anodes) are connected (0=disabled)
#define DEFAULT_BPM_DIGITS_COMMON 6

 

 

You would have to set the DEFAULT_BPM_DIGITS_ENABLED either to 1 or 2, depending on which LED digit you got (your link doesn’t make this clear).

 

Here a link to the MBSEQ V4 schematic: http://www.ucapps.de/midibox_seq/mbseq_v4_bpm_digits.pdf

MB808 only supports 3 digits (since BPM is working at .0 resolution), therefore connect:

  • the common line of the first digit to D2 of the DEFAULT_BPM_DIGITS_COMMON DOUT

  • the common line of the second digit to D1 of the DEFAULT_BPM_DIGITS_COMMON DOUT

  • the common line of the third digit to D0 of the DEFAULT_BPM_DIGITS_COMMON DOUT

 

Best Regards, Thorsten.

3

Thank you Thorsten,

Can i used D3 D4 D5 ect … of the DEFAULT_BPM_DIGITS_COMMON DOUT for led ( for exemple for Beat, Recod and live switch)

If yes, i need to used resistor for the D3 D4 D5 ect … ?

4

No, unfortunately the DEFAULT_BPM_DIGITS_COMMON assignment allocates the complete SR

Reason: if you would add additional LEDs, they wouldn’t be so bright anymore since the DOUT is used as current source for all 7 segments of the digit.

Therefore such an option hasn’t been considered in the firmware configuration.

 

Best Regards, Thorsten.

5

Thorsten, it’s correct that the a,b,c,d,e,f,g and dot connection is sahred (the same) for the 3 displays and only cathode (or anode ) are separate ?

6

Thorsten, it’s correct that the a,b,c,d,e,f,g and dot connection is sahred (the same) for the 3 displays and only cathode (or anode ) are separate ?

 

yes - the segments are controlled time-multiplexed.

 

Best Regards, Thorsten.