adamstan

Don't know if it's right place to post, but... I've designed a replacement for the AOUT_LC module, using two 4-channel 8-bit AD7226 DACs. They have parallel interface, so I used two shift registers (one per chip) and 2051 for addresing. It is supposed to work like this (I've made some minor changes to cv_aout_lc.inc): - Two shift registers are loaded - Values are latched into registers, and in the same tame, latch signal triggers interrupt on 2051 - 2051 latches values into DAC by setting !WR pin HIGH - 2051 increments DAC address - 2051 sets !WR LOW, enabling new voltage to be written in next channel - next two bytes are loaded into SR's... and so on But after what I've read in this topic, I've checked its accuracy, and with 8bits, +-LSB or +-2LSB is really bad for driving V/oct VCO in polysynth... :-/ Am I doomed to buy MAX525 or clone some 80's circuits with single 14bit DAC and S/H? Or are there other ways?

Is this code correct? USER_DIN_NotifyToggle ;; check for control surface buttons - the CS handler will jump ;; back if the button has not been assigned to a CS function goto CS_MENU_BUTTON_Handler CS_MENU_BUTTON_Handler_Return ;; Ok, button not assigned to CS, send a MIDI Note event movlw 0x90 call MIOS_MIDI_TxBufferPut movf MIOS_PARAMETER1, W ; button number addlw 0x18 - 4 ; add 0x18 (C-1) - 4 (first four buttons assigned to CS) movwf MIOS_PARAMETER1 ; store key number temporarily in MIOS_PARAMETER1 call MIOS_MIDI_TxBufferPut movlw 0x7f ; send velocity=0x7f when button pressed, 0 when button depressed IFSET MIOS_PARAMETER2, 0, movlw 0 call MIOS_MIDI_TxBufferPut movwf MIOS_PARAMETER3 ; put velocity in MIOS_PARAMETER3 movff MIOS_PARAMETER1, MIOS_PARAMETER2 ; put key number in MIOS_PARAMETER2 movlw 0x90 movwf MIOS_PARAMETER1 ; put 0x90 in MIOS_PARAMETER1 call USER_MPROC_NotifyReceivedEvent return

Thanks. I think that is what I'm looking for - but I need not only to transmit these notes via MIDI OUT, but also send them locally to CV channels without connecting MIDI OUT to IN. Does above code allow this, or is there something more needed?

Hello. On my neverending ;-) quest for building polysynth using MidiBox as keyboard decoder, I started to wonder if it's possible to 'merge' MIDIO128 functions into MidiBox CV so it would become all-in-one keyboard scanner ,voice assigner and MIDI interface - in one CORE module. It would be also nice to have Mono/Poly/Unison switch to change these settings without diving into menus. Do you have any suggestions?? Thanks in advance :-) PS I've found quite cheap PCB manufacturer, and nearly all boards are designed, so maybe in few months the quest will be completed :-)

THANKS :) :) :) You are truly great MidiBox Guru :)

So, correct me if I'm wrong, and I'll try to modify software myself: - I have to add 'velocity stack' - I have to push velocity values on this stack together with pushing notes on note stack (probably by adding some lines to note stack handler) - I have to send out to CV channels velocity values instead of note numbers... Well... I need to become more familiar with PIC assembly language (some instructions are strange to me - I've found a book on PIC16, but it seems that PIC18 has larger instruction set...) and there is a chance, that it will be done... But at first I want to finish basic, non-velocity-sensitive version of my synth, and then maybe add velocity option...

Because i need eight voices, so eight CV channels are needed for pitch, and another eight for velocity. And my question is, how to 'bind' or 'gang' pitch channels with velocity channels.

Is it possible? I mean, connecting two MidiBoxes CV to the same Midi In, and setting one to respond to notes (in Poly mode), while the second responding to velocity. The problem is, that it should respond to the same notes - so there is a 'Poly' mode for velocities necessary. Let's look at the example: - note C1 with velocity 64 has been received - first Midibox forwards its pitch to CV channel 1 - second Midibox has to forward its velocity to its CV channel 1 - when next note is received, and its pitch is forwarded to channel 2, its velocity should be also forwarded to channel 2 on 'velocity MidiBox'. Is it possible with current version of software? What changes are needed?

Thanks. This algorithm is clear and certainly OK. Now I have to get more familiar with PIC assembly language and implement it. Or, if that fails, I have another idea. My synth will use Voltage-Controlled ADSR's, and will probably have six voices. So seventh or eighth channel of MIDIBOX_CV, or even digital out from MIDI/O can be set to react on CC#64, and when CC#64 is high, switch Release Time to longest value (which is about minute - long enough for standard playing).

OK. If that's not implemented, maybe I'll try to pass gate signals through latch, and use some logic to connect pedal input to this latch. Or look carefully into applications code and try to implement it - but I doubt I can do it - if there are any programmers who know how to do it, please write it here. But I think, that I'll just try to use some extra hardware logic.

Hello everybody :-) I'm going to build analog polysynth using MIDI/O128 for keyboard scanning and connecting it to MIDIBox CV for driving voices. I have one question - does MIDIBox CV respond to CC#64 (sustain) messages?? (does it hold gate signals while pedal is pressed?) If not, what should I do to make it do such a thing?? Thanks in advance Adam St.