MidiBox CV / AOUT

[Tanstaafl]

been working on the MB CV for a few days now and am ready to lay it down on copper.  however,  i am a bit confused about something.  (probably missing something obvious)

the AOUT module page states "The AOUT module provides 8 control voltage (CV) outputs with 12 bit resolution and 2 gate outputs", but the MB CV page states "# 8 CV outputs with 12 bit resolution# 10 gate outputs".

where would i find the other 8 gate outputs? or am i overlooking something?

thanx in advance MB GURUs !

gb

[moebius]

HA - I was faster than Gurus ;)

This is not obvious, but can be read from the sources - 8 additional gate signals come from Core module J5 connector.

And to activate these, you should re-compile application, with enable_j5 set.. (change it from 0 -> 1)

(from main.asm header)

#define ENABLE_J5 1

Bye, Moebius

[Tanstaafl]

thanx moebius!

one more silly question.....

will J5 directly drive the gates... or should i build a buffer type circuit... ala the resistor/transistor network on the AOUT module?

anyway... thanx again

gb

[moebius]

Err.. Do you have revisited AOUT schematic? Current version doesn't buffer gate at all, but instead gate LED should work as intended ;)

GATE inputs (in synths) should react to voltage level, and not sink too much current.. And this is the case in designs I have seen.. and also other DIY midi-cv converters usually drive gate voltages directly from uC pins.

At least PIC has protection diodes in those port pins connected to J5.. but if you're up to build some "frankenstein" patches with a modular synth - it could be ok to buffer outputs.

Couple of PNP transistors and few resistors should work..

(See input buffer of http://www.ele4music.com/pdfs/deg2a.pdf for reference)

Bye, Moebius

[Tanstaafl]

duhhhh silly me.

i've done this with TTL / MML  on my paia and DIY stuff, just wasn't thinking.

thanx moebius.

gb