jab Posted November 1, 2015 Report Share Posted November 1, 2015 Hey guys - I'm looking at repurposing my V4L board as a plain old button/led matrix and wanted to double check with you folks before I break something. After studying the schematic (http://www.ucapps.de/midibox_seq/mbseq_lite_blm.pdf) it seems like I should be able to make some custom cables to connect this to a DIO_matrix module. Here's what I concluded:J5A/J5B A0-A7: connect to DOUT #1 O7-O0J15A D0-D7: connect to DOUT #2 O7-O0J15A Vs: connect to VsJ10 D0-D7: connect to DIN #1 I0-I7Anyone see any issue with this? Or is there a better way to do what I'm after? Quote Link to comment Share on other sites More sharing options...
TK. Posted November 1, 2015 Report Share Posted November 1, 2015 Yes, it should work this way! :)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jab Posted November 15, 2015 Author Report Share Posted November 15, 2015 So I got around to testing this out... wired up as I explained above, using the following in my NGC file:DIN_MATRIX n=1 rows=8 inverted_sel=1 sr_dout_sel1=1 sr_din1=1 DOUT_MATRIX n=1 rows=8 inverted_sel=1 sr_dout_sel1=1 sr_dout_r1=2 EVENT_BUTTON_MATRIX id=1 fwd_id=LED_MATRIX:1 type=NoteOn key=36 lcd_pos=1:1:2 label="Matrix1 Pin %2p %b" So with this code (for testing only) I noticed that when i push a button, the button's LED lights fully (as expected) but the LED in the same column, but one row above also lights faintly.i've double checked all my wiring and can't find anything wrong. My SEQ_V4L always worked perfectly so I feel confident in my soldering, but... Any suggestions on what to test? Quote Link to comment Share on other sites More sharing options...
jab Posted November 23, 2015 Author Report Share Posted November 23, 2015 Still struggling with this... anyone have some advice for me? Quote Link to comment Share on other sites More sharing options...
TK. Posted November 23, 2015 Report Share Posted November 23, 2015 Does it make a difference if you replace the 8 100 ohm resistors by 220 ohm?100 Ohm has been selected in the original circuit since the LEDs are driven from 3.3V pins - but in your case they are driven from 5V pins which could lead to these ghosting effects.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
latigid on Posted November 24, 2015 Report Share Posted November 24, 2015 I don't see a schematic for the SEQ v4 lite. But one trick I found for the BLM is that Schottky diodes from the base to collector help to turn off transistors faster and can reduce ghosting on the current sink side. Also in my case there are 10k resistors from the base to the emitter to reduce power draw, and to provide a current path if the base is ever in a high impedance state. Quote Link to comment Share on other sites More sharing options...
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