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Questions tagged [midi]

Musical Instrument Digital Interface

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What options are there for multiplying clock pulses by non-harmonic values?

I have a MIDI clock signal which will output pulses at 24ppqn and a device I would like to synchronise which runs at 64ppqn. This is equivalent to a an ⁸⁄₃ clock multiplication. My current method is ...
Pernel_Sned's user avatar
2 votes
1 answer
94 views

At a high level, how to design MIDI-controlled audio switching devices for low noise?

I have several use cases for MIDI audio switching. Specifically, MIDI controlled AB pedals and mute pedals. Since these don't really exist, I will need to build my own. (Can you find a MIDI controlled ...
cat pants's user avatar
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0 votes
1 answer
59 views

How to power an audio-level meter / VU meter in a midi-controller project?

I'm building an Arduino-based midi fader controller, and want to also add an audio VU / Level Meter to the enclosure. The Arduino is USB-powered. I bought a standalone audio level meter on AliExpress, ...
jimj31's user avatar
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1 vote
0 answers
90 views

Pi Pico shorted after working fine

After working for a couple of weeks, a pi pico is just shorted. It is used on a board that gets a midi signal as input and controls six mosfets as output. When powered by usb maximum power is drawn, ...
Nico's user avatar
  • 11
2 votes
1 answer
89 views

Identify component: SOT-23 "ADSL" "19"

Pictured is the power section of a midi controller mainboard. It's a PreSonus Atom SQ (The motherboard is labeled "BEEP_Main_Board_V3.0"). The sad story is that it was bought 2nd hand and ...
etgalim's user avatar
  • 21
1 vote
3 answers
399 views

Button multiplexing supporting multiple simultaneous button presses?

I'm looking to build a MIDI controller from some hardware I've salvaged, which includes 30 non-latching buttons and 30 LEDs. I'd like to base the system around an Arduino board (specific type TBD ...
Rob Reid's user avatar
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0 answers
102 views

Problem sending MIDI message using Proteus Simulation Software

Im trying to send a MIDI message using Proteus Simulation Software. The idea is to send a NOTE ON, channel 1, C4 music note with velocity of 127. This three bytes are the following. (Note ON/channel 1 ...
Zlmanuel87's user avatar
1 vote
1 answer
314 views

Using a potential divider to connect 12V input to 3.3V components

I'm planning a project which will involve converting an old pipe organ console into an electronic MIDI controller. I intend to use a Teensy 4.1 in conjunction with an array of shift registers to ...
jsbach's user avatar
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2 votes
2 answers
105 views

Is it possible to power an ATTiny85 and a 6N138 through MIDI in?

I'm working on a MIDI2CV board. The schematic I'm working on is provided by the website of Kevin's Blog. The MIDI cable comes the MIDI out of a Digitakt. It has 5V on pin5. I was wondering if it is ...
Sercurio's user avatar
7 votes
9 answers
3k views

How can I connect multiple potentiometers (~20) to my Arduino without having to have 20 analogue pins?

I'm trying to build a MIDI controller and I'm looking for a clever way of using 20 potentiometers without having to have 20 analogue ports on the Arduino. So far all the functionality I need is for ...
Michelangelo Prisciano's user avatar
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2 answers
510 views

How do I successfully transfer MIDI OUT signal to Windows 7 (32 bit) Desktop PC? [closed]

Things I have: I have an old type MIDI input device (Piano Keyboard Panel) which has a MIDI "OUT" port (female type jack) that has 5 holes. (and no USB port). it has a 9V power input (AC ...
user avatar
3 votes
0 answers
88 views

Is it mandatory to isolate D+/D- to clean my noisy MIDI power supply

I designed a Piano controller with MIDI synthesizer board which works pretty well but there's noise in the jack output. All my board is supplied by the USB (a typical type B connector). I searched ...
Thibaut Bourgeais's user avatar
8 votes
2 answers
2k views

How to identify bits on an electric signal

I am trying to read a MIDI signal. I have used a logic analyzer to look at the signal: The upper picure is the note-on signal that should read 0x90 0x3C 0x7F. The lower picture is the note-off ...
John Am's user avatar
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2 votes
1 answer
977 views

Problem working with MIDI on hardware serial port on Raspberry Pi Pico 2040

I'm trying to make to make a simple MIDI communication with a Raspberry Pi Pico (2040) microcontroller (Arduino core/PlatformIO). I've successfully made it work using USB MIDI with this code (using ...
risk's user avatar
  • 213
2 votes
1 answer
241 views

Digital buffer/driver (74LVC1G07) not outputting signal. MIDI output circuit

I am expericing difficulties with a simple MIDI output circuit. I have checked the input of the buffer and signal is there. However, there is not signal at ouput. . At first I thought that I blew up ...
adrengineer's user avatar
1 vote
1 answer
521 views

HAL USB device library transfer complete callback (USB MIDI adaption)

I have been able to implement Zac Rogers USB MIDI adaptation of the Cube MX USB device middleware: https://github.com/zacrogers/blue_usb_midi I can send USB midi messages on both F103 and F411. It ...
Nicolas SoundForce's user avatar
0 votes
3 answers
115 views

Can I substitute SN74LVC1G04 (single inverter) for SN74LS00 (quad inverter)? (re: simple GAMEPORT to MIDI cable?)

I'm trying to design a simple GAMEPORT to MIDI adapter/cable. However, the original design specifies the 74LS00 which I think is used as a buffer: http://midi.teragonaudio.com/hardware/pc_intfc.htm I'...
SofaKng's user avatar
  • 481
1 vote
1 answer
158 views

Does this circuit look correct to connect DA-15 (Gameport/MIDI) to RPi (MT32Pi)?

I'm trying to connect an older PC with a DA-15 (Gameport/MIDI) to a Raspberry Pi using MT32Pi. The Gameport/MIDI is +5v and the RPi is +3.3v so I'm using an optocoupler and voltage divider. Does this ...
SofaKng's user avatar
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1 vote
2 answers
89 views

Can I use two micro-USB receptacles on a single device so the user has the option of using either?

I make a USB MIDI device and am designing a new version. I'd like to have two micro-USB receptacles in different locations so that the user can choose either, for ergonomic reasons. The easiest thing ...
Andrew Mowry's user avatar
0 votes
3 answers
423 views

Is it possible to use a Smartphone audio jack as MIDI output?

Is it possible to use a Smartphone audio jack as MIDI output? My plan is to use a standard TRS to MIDI cable, like the one Arturias Beatstep uses, to connect a Smartphone/Tablet to a MIDI device. I ...
Hirudo's user avatar
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1 vote
0 answers
339 views

MIDI Output circuit not being recognised by MIDI devices

I'm trying to make a MIDI Out circuit from the Sparkfun web page (https://learn.sparkfun.com/tutorials/midi-tutorial/all). My MicroController is a 3v3 device but I'm using two Not Gates as used in the ...
jwhitmore's user avatar
  • 389
2 votes
1 answer
423 views

How to change from audio-out to MIDI out from same headphone jack?

I am trying to add MIDI OUT capabilities to an audio device - using the same jack. User will select in software if audio or midi is to be outputted. Currently, the audio jack wiring is as shown (R1 ...
Calum Nicoll's user avatar
1 vote
0 answers
682 views

Add MIDI to music keyboard without disrupting its functionalities

As a DIY project I would like to add MIDI capabilities to my Yamaha PSR F51 keyboard. I've found some projects on the Internet as this one, but unfortunatelly in this way the keyboard would not work ...
stenio's user avatar
  • 319
2 votes
5 answers
5k views

STM32 as a MIDI device (I'm lost)

I have an STM32F723. I'm trying to configure it so that my computer recognizes it as a MIDI device via USB. I searched the internet for examples, and read up on USB and MIDI. However, I'm lost in all ...
sylvaing's user avatar
0 votes
0 answers
46 views

midi keyboard lost 7 keys

I have acquired a korg 49 key midi keyboard which has 7 keys that do not work.as set of 5 together then 2 more 2 keys away. what could cause this issue? I have cleaned and tested the contacts and they ...
Nathan Giles's user avatar
0 votes
0 answers
190 views

USB and Serial MIDI

I have a project I'm working on for sending MIDI over USB or over a standard MIDI port using an Arduino Leonardo/Nano (ATmega32u4) and I can't seem to get anything to come over either port. I've ...
Ryan Norton's user avatar
0 votes
1 answer
109 views

How exactly does a computer know what device is connected on the USB port? [closed]

I am working on a mini that uses USB. This is probably something that I can get in the huge USB docs but if I can get a brief response I'll be happy. So since almost all devices interface with the ...
skmbatha katlego's user avatar
1 vote
2 answers
740 views

Can I convert my old Digital MIDI Keybaord Casio CTK 3000 into a MIDI device, which gives only midi output

Recently my midi keyboard was damaged and it is not powering on, But now I realize I don't really need many features including speakers of the keyboard. So I thought I can convert into a small ...
Sandeep S J's user avatar
0 votes
1 answer
60 views

Sharp PC401 Optoisolator Failure

I have a trusty 2005 Edirol UA-20 midi interface, on which MIDI in has recently stopped working. After a bit of testing it appears the Sharp PC401 optoisolator / optocoupler appears to have failed. It ...
Kolleyk's user avatar
1 vote
1 answer
495 views

Not debouncing on a MIDI keyboard

I am modifying an old 90s keyboard (CTK-450 by CASIO) to make it a MIDI controller. I'm going for an Arduino that goes over the matrix layout of the keyboard. The issue I have is with debouncing. ...
ChemiCalChems's user avatar
0 votes
1 answer
166 views

Sampling MIDI Via Parallel Port

I'm using an onboard parallel port on an otherwise disused laptop to try and sample the MIDI output of a very old keyboard. MIDI is a serial link at fixed 32 kbit/s, and so far i've managed to connect ...
chocapic's user avatar
1 vote
2 answers
2k views

USB MIDI Host on a microcontroller

I need to interface a USB MIDI keyboard to a microcontroller host. The microcontroller will be receiving MIDI commands from the USB and occasionally sending MIDI commands. I'm wondering if there are ...
Miguel Sanchez's user avatar
1 vote
1 answer
119 views

Why does my MCU work better when powered to Vcc and PA1=D2 instead of Vcc and GND?

I'm making a MIDI processor, with its power coming ... directly from the MIDI signal itself, as done by the author of this page (see "Powered by MIDI" paragraph): it works well with a 100µF cap. I ...
Basj's user avatar
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0 votes
1 answer
600 views

How can I turn a midi keyboard to a stand-alone piano using Arduino or any other way? [closed]

I have a midi keyboard, but I find it frustrating to start PC, DAW system every time I want to play. Is there a way to use Arduino to create an on the go stand alone piano. (It should work like a ...
Aether's user avatar
  • 193
9 votes
4 answers
2k views

Is this DIN connector suited for MIDI devices?

I'm having difficulties to find PCB mount "MIDI" connectors by a supplier like Farnell, no search with the keyword "MIDI" succeeds. I know a MIDI connector is a DIN5 connector, but there seems to be ...
Basj's user avatar
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1 vote
1 answer
276 views

What component does this symbol represent?

Can anybody please tell me the name of the component represented by this symbol (encircled in picture.)
Zeeshan Dhillon's user avatar
0 votes
2 answers
442 views

Purpose of the Schmitt trigger in this midi circuit

I came across an instructable about using midi with a raspberry pi and I was a bit confused about the first circuit from step 2. What are those Schmitt triggers for and are they really necessary? (...
Sven Haaijman's user avatar
0 votes
0 answers
88 views

Make MIDI messages and audio signal transit in the same jack cable

I know it's a crazy (bad) idea, but still: I hate having many cables attached to a music instrument when I move in the room. Let's take the example of a Akai MPC500 sampler: it is battery powered (so ...
Basj's user avatar
  • 1,936
1 vote
3 answers
480 views

How to keep PWM from "contaminating" analog read values on my pcb

So I'm designing a PCB for a MIDI controller with a lot of slide potentiometers and push buttons. I'm also backlighting the pushbuttons with LEDs running on PWM and I'm worried that the PWM for the ...
SouZ's user avatar
  • 23
1 vote
1 answer
278 views

How would you design a clock in order to play triplets?

If you take a master clock (e.g. 1 Hz) it is easy to get the quarter notes (every pulse), the half notes (every two pulses), and the whole notes (every four pulses) to build a simple drum machine. ...
Ben Madison's user avatar
3 votes
3 answers
3k views

Why optocouplers for MIDI Out/Thru?

I found this article: midi-in-through-out Credits by Zynthian I like that it has notification LEDS for MIDI in/out/thru. However, I also notice there are optocouplers for MIDI Out and Thru, while ...
Michel Keijzers's user avatar
0 votes
2 answers
424 views

Compensating clock drift "by hand" - what have I solved?

Edit: I'm not actually looking for a solution, because short of syncing the hardware clocks (which I can't do) there isn't one. What I'm looking for is an explanation of where the magic -8.4ms I seem ...
damian's user avatar
  • 343
2 votes
2 answers
571 views

Connect MIDI input shield connection to ground with capacitor. What voltage / kind?

The midi specification mentions optional capacitors between connector shield and ground for a midi input: Neither the type of capacitor nor the voltage rating is specified. I would think that the ...
Tim Walther's user avatar
1 vote
4 answers
912 views

Is it possible to use a DPDT switch to swap 2 inputs and 2 outputs?

I want to create a passive device with two MIDI inputs and two MIDI outputs, with a switch that has two states. In the first state, input 1 is connected to output 1, and input 2 is connected to output ...
DLH's user avatar
  • 113
1 vote
3 answers
470 views

Implementing digital control on analog potentiometer [closed]

I have an analog sound processor unit, which uses either ICs or spare components. There are four controls, which are simple potentiometers. I would like to control their levels digitally, storing the ...
yodabar's user avatar
  • 113
3 votes
1 answer
2k views

Do I really need diodes to receive MIDI?

All the schematics above use a diode before the receiving pin on the optocouplers. The problem was, I never able to find the exact same diode as the schematics. Before, I'm using H11L1, but it never ...
Rinaldo Jonathan's user avatar
0 votes
1 answer
420 views

Generating a midi signal from switches or digital logic [closed]

I have a control board I have wired up consisting of various buttons and momentary switches. (For an art project) There are enough for exactly two octaves (C3 to C5). I want to connect these control ...
cat pants's user avatar
  • 357
0 votes
1 answer
224 views

Reverse Engineer DIN 5-pin connector

Summary I have a digitial guitar amplifier that can be controlled via a footswitch. The footswitch is connected to the amplifier via a DIN 5-pin cable. I want to be able to control the amplifier with ...
cajudosu's user avatar
0 votes
3 answers
2k views

Making a simple 1 MIDI IN + 1 arduino MIDI OUT merger (MIDI THRU + TX)

From the Midi DIN spec schematics we can see MIDI THRU is just MIDI OUT directly at the end of a MIDI IN. Is it possible to just add a midi signal from the arduino TX ("FROM UART") to the midi thru (...
mikmikmik's user avatar
  • 139
3 votes
2 answers
1k views

Building a midi project with Arduino + scrap components (optocoupler and diode)

Original title: 300V output Optocoupler in a 5V circuit I'm (new to this) trying to build a midi controller (in and out) with arduino and scrap. I guess I had several questions in one so I changed ...
mikmikmik's user avatar
  • 139