MIDI for the Arduino - Circuit Analysis

[@sandrocavali9810]

Congratulations! 9 years and this video is still superb

[@mikecarroll757]

Such a great and rare video to find. It gives a beginner and an advanced lesson all in one. Well done!

[@NotesAndVolts]

+Mike Carroll Thanks Mike!

[@Marius-vw9hp]

Agree. This is high class Youtubing :)

[@georgekingsley3972]

Instablaster.

[@ltlfrari]

THE best explanation of the MIDI interface. Saved my neck already!

[@NotesAndVolts]

Thanks itlfrari! Glad to hear it :)

[@SL-jm4rt]

This is one of the most clear tutorials I've ever watched. Thank you for the time, detail and clarity. +1 sub.

[@NotesAndVolts]

Thanks PE! Glad you liked it :)

[@neail5466]

What can i say you are the best teacher ever i have seen you do not assume that anyone "must or should know this or that" you do it from grass roots...... Exceptional, wish the videos help all. Even those having no background could get all of this....thank you

[@marvinmatter1501]

man, you're explaining this in such a great way. the visualisation helps a ton, you taking it step by step makes it so easy to follow. big thanks!

[@NotesAndVolts]

Glad you liked it!

[@marvinmatter1501]

@@NotesAndVolts absolutely. Your guide actually made it possible to build our PolyTape-O-Tron in class. Its 4 Casette players with tape loops, whos motor speed is controlled via an arduino that receives MIDI from DAWs. This makes it a 4-voice polyphonic synthesizer. Big fun!

[@analytical_computer]

IT WORKED!!! After months trying, I got it working!!! I love you, dude!!! I used an Arduino Uno (clone) and a 4n35 optocoupler to use my old Casio keyboard as a controller in LMMS (a DAW like Ableton, FL Studio...). All it takes are different resistor values and different coding (100 ohms at opto LED, 1K ohms at collector to 5v, and using SoftwareSerial as input pin instead of main RX pin).

[@Sumida2]

Good job. While it will work fine and not damage anything, the schematic in the video is slightly wrong compared to the actual MIDI standard. It is missing one 220 ohm resistor on the TX pin on output side. That will add up to the correct 660 ohms in series when driven from 5V, and not 440 ohms. The current also drops to more like 5 mA, which is the proper value.

[@xxx7917]

HidekiSamba that is correct

[@tinagolph]

Your video is very enjoyable to watch. the explanations are easy to understand and for someone whose English is not the native language, your English is perfect. thank you

[@RabbitRobit]

This is a clear, clean, informative video. I kept thinking about making a "well, actually..." type comment about the performance of a component, then you would say what I would've said. Great visuals, great information. Again, great job.

[@NotesAndVolts]

+RabbitRobit9876 Thanks RR! Glad you liked it

[@sennabullet]

I just want to thank you very much for making this video. I'd shake your hand if I could! I don't think I have ever seen someone explain a concept quite as well as you did in this video. Beautifully presented. Exceptionally well explained.

[@squarefrog]

Came here looking for why you need the optocoupler on the midi in. Now I know how that entire circuit works. Excellent video, keep them coming!

[@NotesAndVolts]

Awesome! Thanks Paul!

[@sv1onk]

The most well documented video I ever watched. Congratulations.

[@NotesAndVolts]

Wow, thank you!

[@matcarpes]

I'm amazed by how well you explained everything! Seriously, thanks a lot!

[@NotesAndVolts]

Thanks Matheus!

[@nickzambrano]

This video is of supreme quality. Subscribed.

[@NotesAndVolts]

Awesome! Thanks Nick!

[@UpcycleElectronics]

Awesome production quality. A very clear, easily understood, and well articulated explanation. This was my first encounter with Notes and Volts. (Liked/Subscribed/Commented/Saved to personal projects playlist)

[@NotesAndVolts]

Thanks Jake and welcome to the channel!

[@kostaschousianiths6076]

Currently studying electronics engineering, attempting a homebrewed project, I can't express enough how clear your explanation of the circuit is. Congratulations for real!!! (instant sub)

[@NotesAndVolts]

Thank you very much Kostas!

[@tehedx]

Thanks a lot for explaining every component and its purpose in the circuit! This really helped refreshing my memory (20+ years ago). Currently building a MIDI-thru box as a warmup project :)

[@NotesAndVolts]

You are welcome!

[@thetanil3702]

this is one of the best things i've ever seen on youtube. great work.

[@NotesAndVolts]

Thanks Theta!

[@G8tr1522]

This taught me so much more than what I was wanting to know. Great tutorial!!!!!

[@andyq2829]

Thank you very much . You have opened a door for me to enter into the world of MIDI & Arduino . Very much appreciated .

[@erichimmelblau877]

Wow, very well explained. I rarely like videos, but this one definitely deserves one.

[@NotesAndVolts]

+Eric Himmelblau Thanks Eric!

[@TATO10892]

What a magnificent explanation. You've earned an Argentine subscriber. Nice work.

[@NotesAndVolts]

Thank you and welcome aboard!

[@markfdesimone]

This video was excellent! I rarely find resources that do such a good job of demystifying something.

[@NotesAndVolts]

Thanks Mark!

[@boatloan3543]

hey, pal Dave -- thanks so much for this! I was struggling with really erratic signals from my optocoupter but as soon as I added the 4.7K drain resistor, it was rock-solid. Your diagrams and explanations are top-notch.

[@NotesAndVolts]

Glad it helped!

[@konstanzification]

Thank you so much for all the midi videos, I've been watching midi videos for the past few days and yours are the best!!!! Thank you!!!!!!!!!!

[@NotesAndVolts]

You're very welcome!

[@cruepprich]

Beat and clearest explanation I’ve seen on electronics period! Thanks!

[@NotesAndVolts]

Glad you liked it!

[@wackojacko1997]

Super helpful video. Very well done -- direct and to the point. Nothing wasted and very clear. Thank you.

[@NotesAndVolts]

Glad it was helpful!

[@schrotti788]

Thank you! I never have seen a video with such detailed explanation. Great!!!

[@sennabullet]

What an excellent video! Clear explanations with great graphics! Thank you for sharing your knowledge.

[@NotesAndVolts]

You're very welcome!

[@rsrini7]

No Collage / School can teach better than this in 16 mins. Actually i watched this video couple of times to understand it better. Please help to share your knowledge. I am from India and teaching my students. Thanks.

[@NotesAndVolts]

Thanks Srini! I'm glad you like it. Say hi to your students for me :)

[@lopyus]

Nicely explained! You earned a subscriber

[@davidecarollo70]

The best midi explanation on yt! Great!👏👏👏

[@litalienvisual]

Great explanations, it really helpsunderstanding the MIDI In circuitry based on the 6N138

[@lloydrmc]

As happens frequently with such things, I knew most of it already. It's always nice to have all the various gaps in my knowledge filled in and integrated. Most importantly; the style and manner of your presentation is simply marvelous: perfect pacing, pleasing little animated flourishes, and seamless repetition and summarization. KZbin originally served me an episode later in the series, and I'm glad I decided to load the Playlist and watch all of your videos on this subject.

[@t4ttyt3ddyr0ck3r]

So glad I found this channel. I've been looking for some examples of how to use the Arduino as a midi controller, but with full explanations, not just images and codes. I am wanting to use my Arduino with Multiplexers to make something similar to the massive Midi Box 64 controllers, to build a controller for a VST Midi Modular!

[@marcuhrich3784]

This is the best video I've seen on the topic. Nice work and thanks!

[@TangoMikePapa]

Excellent and well produced video!

[@playinmyblues]

Great video. I have been wanting to learn about MIDI for a while. It made some things very clear and look for more videos like this.

[@eirikolsnes]

Very nicely done! Looking forward to watching the rest right away : )

[@NotesAndVolts]

Thanks Eirik!

[@Colin_Ames]

What an excellent tutorial. You could not have made it any clearer!

[@NotesAndVolts]

Thank you!

[@EBJ0]

Excellent work. It is great to find a well done explanation of this circuit. Thank you!

[@NotesAndVolts]

Thanks Joe!

[@the_rabbit]

This is amazing. I'm building an Arduinoboy and this just helped me understand what the hell I am actually doing.

[@vikinglord7252]

Epic video! I'm about to start building a midi sequencer for my microcontrollers class and this was a great overview! Now on to some more of your vids!

[@yusun5722]

Very good videos. One question I have is that at 10:28: how can the diode has 5V when there are two 220 ohm resisters are connected in serial?

[@mstergtr]

You're right, it can't be 5 volts. The principle should be the same with the lower voltages amounts I suppose.

[@ericwright3382]

When the LED diode has the voltage in reverse, it has near infinite resistance. While yes, there are a couple 220 ohm resistors in series with this very high resistance... the diode will see approximately -5 volts. [Say the diode reverse biased is 1,000,000 ohms... the math would be 1000000/ (1000000+220+220) multiplied by -5v. That means the diode is seeing -4.9978V. That is too close to the spec that says the maximum reverse voltage of 5.00.] Reverse voltage kills diodes without much current, so those resistors don't help... you need a typical diode backwards and in parallel to the LED, to protect the LED.

[@robfielding8566]

I'm building a MIDI filter with Arduino Pro Mini, and noticed the odd thing about gnd of MIDI out being connected at one end of the cable. I was able to get the board to come up with power from a MIDI in. It can't use the optocoupler (because it gets power from IN). It works (a MIDI IN/OUT filter that can be reprogrammed with Arduino code). The main deviation is that I connect the IN.4 (pin 4 of MIDI IN) straight to regulated power), IN.4 to 220ohms to 5v, IN.2 to ground, IN.5 to rx. Then I think it's OUT.5 to tx, OUT.4 to 220 ohms to vcc.

[@AlessandroGiancane]

Serial transmission (in particular MIDI) begins from the least significant bit up to the most significant bit. So, 10010100 at the beginning of the video actually has to be read as 00101001, which is not a MIDI message. Other than that, GREAT video!

[@Johnzoful]

Fantastic video, I'm just getting into all this stuff and this kind of circuit-first approach is super helpful. Thanks so much!

[@NotesAndVolts]

+Johnzoful Thanks Johnzoful! Glad it helped.

[@mariusvanhorssen3047]

Excellent video. I found only one fault, the conclusion around 1:55 is wrong. The LSB is transmitted first. So, the interpretation of the data is incorrect.

[@fiorettim]

isn't the anode the negative pole though, it being the part where oxidation occurs, whereas the cathode is involved with a reduction reaction and therefore the positive pole (attracts electrons)

[@chromatic-me]

I think the reason for the naming is that in a rectifier circuit, the positive voltage appears at the “anode” of the diode. I agree that it seems wrong in the video.

[@fphenix]

I believe from 1:40 to 2:00 is misleading because it is shown on a timing diagram. AFAIK, the LSB is sent first (i.e just after the Start), the MSB is sent just before the Stop, just like RS232. Hence the message here is actually 0x29 (not 0x94 as you imply) and 0x29 is most likely a data byte, certainly not a Status byte which must have its MSB high. So a message "Start note / channel 5 (4+1)" should be drawn as L(Start)-LLHLHLLH-H(Stop) on a timing diagram. Watch out, I've seen several wrong diagrams on the Internet...

[@fphenix]

On the other hand I loved your part on Optocoupler.

[@NotesAndVolts]

Hi Frederic. Midi is big-endian and the MSB of the status is always low.

[@fphenix]

That's incorrect. BTW: I'm talking about the serial physical communication, not how to read a byte on a screen! The status messages go from 0x80 to 0xFF, that means MSB=High right there and serially the MSB is sent last just before the Stop-bit (so close to the right hand side on a timing diagram). Watch this (esp. from 16.40): kzbin.info/www/bejne/jGGvnnuDapmhrcU

[@NotesAndVolts]

kzbin.info/www/bejne/b5bRp5iffpWYnZY at 12:40

[@fphenix]

Yep, it confirms I am right: the oscillo shows the 0x90 as Start00001001Stop, so LSB first, MSB last. Funnily enough the diagram he then pops up is wrong, but the scope doesn't lie!

[@cookedaudio]

So does the Tx have to be 5V? Could it be, say, 3V and work? I was thinking about using an ATtiny for MIDI out (@ ~3V) - I guess I'd only need one output pin for control? Excellent video, thx so much!

[@VasaMusic438]

What a Great Tutorial !!! The best I ever met !!! Thanks

[@NotesAndVolts]

Thanks Pierluigi!

[@TutosIngenieria]

Excellent tutorial, how did you do it?

[@snugglepuff33]

This is just an amazing channel.

[@NotesAndVolts]

Thanks Kevin!

[@lucaguglielmetti3806]

this tutorial is amazing! congratulation for the channel

[@tubeDude48]

Although I understand all of this and have built a number of Boxes with a number of: IN / OUT / THRU Jacks; your instructions are Right-On.

[@NotesAndVolts]

Thanks Ted!

[@GustavoMM1972]

Hola, una consulta, el 6n138 solo necesito para la entrada midi? Mi proyecto es enviar comandos CC# a un roland gr-55, necesito poner un 6n138 en el circuito de salida? Gracias

[@HRSCourses]

Thanks for this really clear explanation. Never knew this, now I know.

[@thoyibbasarah3302]

What about working with 3.3 MCU like STM32?.

[@lqr824]

Excellent video but how do you handle the timing of bits coming in on the Arduino accurately? (I'm not looking for an answer here, but I'd like a link to such a video, or if there is none, it'd be an idea for a video. My understanding is that the Arduino language is just Java, and it's too jittery to do something with tight timing requirements like a MIDI clock. Yet the existence of this current video certainly implies it's possible.)

[@Anonymous-hd7en]

Can we modify the circuit a little bit by using Tx with ground Not Tx with +5 , by adding 220 ohm resistor in line with Tx . So that the signal will be inverted in the other side ?

[@caritas3015]

Fantastic tutorial, I love the graphics also. Just the right amount of detail always validated by an example. Well done! I am definitely a subscriber now and cannot wait to see your website. Thanks and keep it up, please?

[@NotesAndVolts]

Thanks Stevie! Welcome aboard

[@mrtomgreeen]

At 11.04 I don’t understand why you say it’s passing 0.7v? I thought it subtracts the 0.7v forward current from 5v leaving 4.3v to pass through the LED?

[@jeberle1]

The two components (the diodes) are in parallel. If the component on the left were an open circuit (missing), the component on the right would see all 5V. If the component on the left were a short circuit (just a wire) the component on the right would see 0V. The component on the left has a voltage drop of 0.4V (imagine it's a resistor), so the component on the right sees that same voltage, 0.4V. No more or less. This is w/in the diode's spec and so does nothing, nor is it harmed by this arrangement.

[@mindseyetechnology4095]

great video - how about a version with no music track ?

[@robertrobert5583]

An excellent video. Thank you for posting it. I wonder if you might consider not using background music though? My type of hearing impairment makes speech harder to follow against background noise. Best wishes.

[@EytanKoch]

Great video! I totally subscribed! I'm confused about one thing, though. Wouldn't there be a voltage drop as the 5 volts goes across the two 220 ohm resistors?

[@philnelson2364]

Actually, it's a current limiter.

[@SteveDavidsonGuitar]

Holy smoke! That was clearer than 8k res.......SUBSCRIBED!

[@NotesAndVolts]

Thanks Steve! Welcome to the channel

[@iddeegee]

UPDATE. I could get it to work with 4n35 only (sw serial is not a good idea for midi lots of misses so RX is a way to go). Same diode between 1 and 2, 1 goes to (midi 4) thru R1 (220-330+ Ohm)... (use any you have), 2 goes to (midi 5). 4 goes to GND, 5 goes to RX and thru R2 (800-1.2K) to 5V. That's it. 3 and 6 pins are not used. OLD I cannot get it to work with 6n136, PC817, 6n138 all of them work separately, but not together with the Atmega328p. Tried 2 different functional midi outs. Tried it with 2 new Arduino Nano, with a standalone atmega328p on a board (with all required components) Rx,tx are workings because I use them to upload code via USB-TTL. I've tested the schemes manually by connecting +5v to pin4 and ground to pin5, so i can get LOW signal out of RX, which I can read on any digital or analog inputs, even if connected to rx on arduino. So it works by connecting external VCC. But if I connect to midi outs (tried 2 different 1working with 100% working cables) to this scheme it just does not react at all... It does not read. I've tried Midi input test example, serial software, just serial with baud rate 31250... it just does not work and I don't understand why.

[@geraldoribeiros]

Excellent video. Please do a tutorial talking about rotary encoders and MIDI controllers.

[@improziv]

Excellent tutorial!!

[@aleviste19]

This is a great video. It has cleared up lots of my electronic questions about midi. I'm currently working on a project that would take audio clock and translate it to midi clock. Do you think you could make a video that explains how to create the 10 bit streams that allow midi to be entered into the arduino

[@Boxcow45]

Great tutorial. Love this channel!

[@NotesAndVolts]

Thanks Boxcow!

[@krzysztofwitkowski6982]

Unfortunately, MIDI out circuit from this video can destroy ATmega IC. (I done it two times ;/) You should use transistor to separate microcontroler pin from MIDI out. But still very good video, analysing of in and out circuits helped mi to understand how actually MIDI transmission works

[@abhilashpatel1809]

can you please give more information on whyATmega IC get failed.

[@pekkagronfors7304]

Revisited this video again. This is really god stuff.

[@alkatechnology]

interesting explanation brother, keep spirit to give us good information bro

[@NotesAndVolts]

Thank you, I will :)

[@FPChris]

Outstanding. Here in 2024

[@DeathmetalSaiyan]

Perfect explanation!! Keep doing your thing man :)

[@NotesAndVolts]

Thanks Luke!

[@StevenFAllen]

Very good series. Tahnks

[@claudiostano]

Hello !!! I'm a total newbie. Anyway, I think I got all the explanation !!! Super cool video, then !! I'm left with one little question: what the 220 Ohm resistor beside the Rx pin is there for? =)

[@NotesAndVolts]

Hi Claudio. When the transistor turns on, it creates a near short circuit between power and ground. This resistor prevents that.

[@sambanks2996]

Excellent tutorial thanks!

[@autofigure00]

that was extremely informative and helpful

[@gil.langlois2732]

Is it possible to use an Arduino to convert a USB/MIDI keyboard to a regular MIDI IN and OUT ? Thanks!

[@nathanbotts2498]

Awesome explanation! Many thanks!

[@NotesAndVolts]

Thanks Nathan!

[@thierryeymard9259]

fantastic,very well explained...thx

[@NotesAndVolts]

Thanks Terry!

[@vibertthio]

really great even for student majoring in EE

[@zaidhussain5206]

Thank you so much for details , very informative

[@NotesAndVolts]

Thanks Zaid!

[@pionyir]

great tutorial! thanks for sharing

[@gabrielepippo2646]

Good video, but i cannot receive messages from PC...i use Arduino Uno, your explained midi interface (but i have try also others 2 schemes), MocoLUFA midi for Uno, Roland D10 keyboard and Midi Library. Just i want take messages/notes from keyboard and get back reply from PC, but all notes/bender/control change go at PC musical software correctly, but none go back to keyboard, i see RX led on arduinio flash when a note is played from PC but i dont receive none on Roland keyboard. Connexion and interface is ok, if i play a note from arduino they reach Roland...but no from PC...any got same problem?

[@zakman3595]

Great Tutorial but i would like to ask you how you connect the midi to pc? Via a usb to midi converter. And if so how can you bypass it, to connect directly throught usb?

[@NotesAndVolts]

Hi orfeas. To connect 5-pin Midi to your PC you will need a Midi interface. Many audio interfaces for your PC have Midi jacks as well.

[@zakman3595]

Also i would like to ask because i have a problem with the pots. My status byte is always 90 (note on) and i want it to be B0 (control change). You know why this is happening?

[@bubuElec]

Amazing video !! ⭐ Thanks man 🙏

[@aidanhanlon6290]

Hey, I’m wondering if anyone knows if there is a signal sent when a midi device is paired with another and if that signal is readable? Ie. if I built a midi controller that connected to say a multi channel midi enabled synth would there be a signal when both devices are paired together regardless of parameter changes? I imagine something like this: Midi Controller(MC) Midi Instrument(MI) MC pot set to CC32 MI “attack” is CC36 MC 32 xxxxxxxxxxxxx MI 36 MC 36 -------->MI 36 X = no connection -> = connected If there is a message does anyone know how I can approach reading that data to actuate LEDs? Cheers

[@gismosgadgets8343]

thank you so much for this video. was just what i was looking for. keep up the good work. ~GG

[@NotesAndVolts]

Thanks G&G!

[@gismosgadgets8343]

:-)

[@hollowneedles]

Can you tell me why the hell they chose such unintuitive pinout numbering for midi? Is there a reason that it's not sequential from one side to the other?

[@motelflamingo]

Great videos, man! Thanks, I'm stunned.

[@NotesAndVolts]

+Guilherme Barros Thanks Guilherme! Glad you like them

[@Theghostescapes]

Does the midi output from a Casio keyboard to the arduino have some sort of buffer? I have a circuit that tests for 4 keys to be pressed simultaneously, and then it sets a pin to HIGH for ten seconds. What I have found is that if I press those same four notes within that ten second period, it adds additional time for the output pin to be HIGH (triggers a relay), as if there is a buffer from the midi device ready for the circuit to read it. Any ideas?

[@NotesAndVolts]

Hi Ghost. There should be no reason that the MIDI output form the casio should be delayed in any way. I would go back and check your program to make sure it is handling the incoming messages correctly.

[@jacksonv1ll836]

What is the purpose of the diode connecting on the base of the first transistor?

[@ericwright3382]

That is the photodetector diode that 'sees' the optical transmission of the LED. They operate in reverse bias and conduct when they receive the light, thus turning on the transistor.

[@bivouacrecording3412]

Do a video on MIDI in out communication via Bluetooth LE to Arduino please!!! What libraries do I use, code tips, etc. That would be very helpful! Thanks!

[@els1f]

this is great, you're great... thanks!

[@seoulrebel007]

Great video but I have to ask do you really freehand that well?

[@NotesAndVolts]

LoL! It's all smoke and mirrors