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Navicat

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Posts posted by Navicat

  1. TR-808 Velocity Control

    in Design Concepts

    Posted

    Here is a velocity control for each voice module of a TR-808. The concept is simple..

    What i did is i took the accent circuit from the original schematics and i place a digipot that will control the velocity for every single voice separately.

     

    A Digipot chain will be connected at J19 of the STM32F4 Core. Each Digipot is controlling the Velocity Value on each instrument. So let's see.

     

    A Pin from Dout module sends a Trigger of +5 Volts. One Branch goes at the Trigger in of the Voice module.

    The other branch is going into my circuit.

    The digipot controls the velocity level from +5 volts to +15v. ( Even with 0 Velocity a 5v minimum trigger must go in voice module so we have sound.)

    The result is a Trigger voltage  from +5v to +15v that goes into the Accent in of the voice module.

     

    What we have here is a velocity control for every single note. :rolleyes:

     

    I Need help on how to programm Digipots to do this job.

     

    Here is the schematic Accent 5-15v.PDF

     

    Regards Tilemachos

    • Like 1

  2. AOUT_NG 12 CV OUT

    in Design Concepts

    Posted · Edited by Navicat

    AOUT_NG is using the TLV5630 12-bit voltage output DAC. It has 8 channels outputs for CV.

     

    I found that LMP92001 is the same but with 12 channel outputs for CV. I think that STM32F4 board can easy handle this IC since it is the same but with 8 more channels.

     

    Here is the Datasheet:

     

    http://www.ti.com/lit/ds/symlink/lmp92001.pdf

     

    I think it would be great to have 12 channel of CV.

    I am waiting for answers if it is possible to control this with mios and how to do this.

    I can fast make a prototype board ( spend money :P ) when answers are positive and i will share schematics and board files.

    Also i have a DIY SMD oven to bake the board. ( I already did 0201 resistors soldering with my oven)

     

    Regards Tilemachos

  4. mbhp core stm32f4 ( J19 question )

    in MIDIbox SEQ

    Posted · Edited by Navicat

    Well I have an idea!

     

    I'll make a daisy-chain of 4  AD5204—4-channel Digipot ---> http://www.analog.com/static/imported-files/data_sheets/AD5204_5206.pdf

    That makes 16 Digital Pots.

    AD5206 —- 6 channel Digipot does not allow Daisy-chain :brr:

    The chain will be connected at J19.

     

    A doutx4 will be connected at J9.

    The first 16 shift register outputs of the Dout will go in each Terminal A pin of each digipot.

    All Terminal B pins will connected to ground.

    Finally the Wiper pin of each digipot will be my CV OUT. A voltage will be produced between 0..+5v

     

    For my purpose i will drive this signal thru a Noninverting TL-072 with +15 to make the signal 0...+15v as i did in the previous schematic.

    You think that this will work? I think it is really faster,more reliable and with 256-position pot will have high resolution.

  5. mbhp core stm32f4 ( J19 question )

    in MIDIbox SEQ

    Posted

    Yeah my main idea was to clone j8/9 at j19 :)

    It was in my mind digipots and thank you for the tutoria link.

    I think digipots is a good idea and more reliable in theory.. I must squeeze my mind on how to make it!

    Thank you very much!

    I will give a try! If you have ideas like this or a complete solution to my problem i can't wait to message me!

    Thanks again.

    Regards Tilemachos

  6. mbhp core stm32f4 ( J19 question )

    in MIDIbox SEQ

    Posted · Edited by Navicat

    Here is my plan of the DOUT to R-2R DAC. I need 4 more CV Outs like this!

     

    Take a look : http://www.docdroid.net/ri8z/dout-cv.pdf.html

     

    ________

     

    Update:

     

    Here is my project (not finished). It is a TR-808 Midi Interface with velocity outputs. Take a look!

    I need the extra DOUT chain for some more CV Outs for the velocity and the rest Dout channel for trigger voices with +5v

     

    http://www.docdroid.net/rj0u/tr-808-midi-interface1.pdf.html

     

    Regards Tilemachos

  13. DOUT to CV with R-2R Ladder

    in Design Concepts

    Posted

    Thank you very much for help me understand this!!!

     

    No i need any voltages between 0 and 15 volts with as much as high resolution i can get.. but 8-bit is ok!!

    Here is an example!! Thanks for your help!

     

    0 volts in = 0 volts out

    1 volts in = 3 volts out

    3 volts in = 9 volts out

    3.5 volts in = 10.5 volts out

    until i go up to

    5 volts in = 15 volts out

     

    That's amazing!!!

     

    Regards Tilemachos

  15. DOUT to CV with R-2R Ladder

    in Design Concepts

    Posted

    Thank you for your answer!

     

    I know about Aout_LC and is really similar to that i want!

    But i need something different and i am really sorry i did not explain!

     

    What i wanna build is a module with with up to 8 CV channels that i will use to control the velocity on a TR-808 clone...

     

    Velocity on a TR-808 is a Trigger pulse of 1ms width with voltage from +5 and +15

     

    Here is my idea taken from another project.. will this work?

     

    cv_ladder_808_velo.png

  16. DOUT to CV with R-2R Ladder

    in Design Concepts

    Posted · Edited by Navicat

    This is a resistor ladder on a Dout module that can produce Controlable Voltage that midibox sequencers can handle

     

    ;; DOUT 160k 
;; D7 ---o---/\/\/\---* 
;; 80.6k | 
;; D6 ---o---/\/\/\---* 
;; 40.2k | 
;; D5 ---o---/\/\/\---* 
;; 20.0k | 
;; D4 ---o---/\/\/\---* 
;; 10.0k | 
;; D3 ---o---/\/\/\---* 
;; 5.1k  | 
;; D2 ---o---/\/\/\---*----CV Out-----------------------------------o ( 0v <----> +5v )
;; 220 Ohm 
;; D1 ---o---/\/\/\--------o free assignable trigger 
;; 220 Ohm 
;; D0 ---o---/\/\/\--------o another free assignable trigger

    __________________________________________________________________________

     

    What i wanna ask here is..

     

    How can i use a shift register with a resistor ladder as that.. but with higher voltages.. i need to go from 0 to +15v

    I need to use a different from 74HC595 that DOUT uses or is there another way?

    I saw something similar before but i am not so sure.. maybe a TL074 can do the job like that in this image:

     


    cv_ladder.png

     

    Regards, Tilemachos

  17. MB808 from the begining, sources of info

    in MIDIbox SEQ

    Posted · Edited by Navicat

    Thanks Throsten for this!

    Dout to CV!

     

    A question for this..

    The output voltage is between 0v and +5V right??

     

    If yes is there a way to make this work between 0v and +15?

     

    Or far away better for TR-808: Accent = Trigger pulse between +5v and +15v

    My target is to make a Dout Trigger pulse of 1ms width between +5v and +15v ( This will be the accent for 808 voices )

     

    Update:

    I know i need a shift register that will be operateable at 15 volts..

    I found that http://www.ti.com/product/cd4094b can operate at those voltages but this is not a 3-state output register.. Is this a problem?

     

    Regards, Tilemachos

  19. 4.3" TFT LCD on Seqv4

    in Design Concepts

    Posted · Edited by Navicat

    Yes i figured it out.. I 'm under datasheet reading now.. I think will be not a problem to make an lcd driver and mios compatible..

    Excuse me for my bad English if you guys see any mistakes!

     

    :smile:)

     

    EDIT :

     

    What about using the J16 on MBHP_CORE_STM32 for wiring this lcd??

    I will make drivers from the begin and i will make it mios32 compatible..

    What you think it is possible??

  20. 4.3" TFT LCD on Seqv4

    in Design Concepts

    Posted

    Thanks for your reply Thorsten

     

    First of all STM32F4 can support those lcd's.. i 'm just asking the pinning :)

     

    I'm making a clone of TR-808 and i wanna use your amazing Midibox Sequencer. I will not use the old MB808 seq... My design started from the begin and here is my concept :

     

    1) TR-808 Voice Boards designed from the begin with SMD compoments wich means smaller and cheaper pcb. ( I have my own DIY SMD oven :D )

    2) Midi Interface wich means you can have different Accent(Velocity) for each instrument from a digital sequencer like midibox.

    3) More voices than the original TR-808. ( I ll add Guiro and maybe some extra snare drums and also i am planning too add some 909 voices.)

    4) Cymbal / Hi Hat / Hand Clap / Maracas / Snare Drum alternative noise inputs from front panel with patchcables. Alternatives sounds will be : Original Pink/White noise from 808 circuit or a 909 circuit or any other noise source,even a microphone.

    There will be many future adds that i am currently working on..

     

     

    I want to use the midibox seqv4 but i wanna make a different version with GUI and real buttons. ( Midibox DR and MB seqv4 is not enough for me) I need to make a module that will help me make my dream come true and give some ideas so the midibox sequencer project go further.

     

    Here some pictures from my work on TR-808 voiceboard cloning in Altium Designer.

     

    2.png808_pcb.png3.png

     

    Best Regards, Tilemachos.

  21. 4.3" TFT LCD on Seqv4

    in Design Concepts

    Posted

    Hello..

    I am building a project based on the MBHP_CORE_STM32F4

     

    I wanna add a 4.3" TFT LCD and the module i will use is this : http://www.4dsystems.com.au/product/4DLCD_FT843/

     

    There is a 10 pin out from the screen.

    Here is the datasheet : http://www.4dsystems.com.au/productpages/4DLCD-FT843/downloads/FT843-4.3-Display_datasheet_R_1_2.pdf

     

    Here is the pin out :

     

    PIN                SYMBOL

     

    1  ------->        3.3V

    2  ------->        SCK

    3  ------->       MISO

    4  ------->       MOSI

    5  ------->        CS

    6  ------->        INT

    7  ------->        PD

    8  ------->  AUDIO_SHDN ----> Audio shut down ( dont know if i need it )

    9  ------->  AUDIO_OUT   ----> Audio Out ( dont know if i need it )

    10 ------->     GND

     

    Any help on how too connect the pin out on the STM32F4Discovery pin out??

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