This should count as a hack: making music from a thing that should not sing. In this case, [SIROJU] is tickling the ivories with a Brushless DC motor, or BLDC.
To listen to a performance, jump to 6:27 in the embedded video. This BLDC has a distinctly chip-tune like sound, not entirely unlike other projects that make music with stepper motors. Unlike most stepper-based instruments we’ve seen [SIROJU]’s BLDC isn’t turning as it sings. He’s just got it vibrating by manipulating the space vector modulation that drives the motor — he gets a response of about 10 kHz that way. Not CD-quality, no, but plenty for electronic music. He can even play chords of up to 7 notes at a time.
There’s no obvious reason he couldn’t embed the music into a proper motor-drive signal, and thus allow a drone to hum it’s own theme song as it hovers along. He’s certainly got the chops for it; if you haven’t seen [SIROJU]’s videos on BLDC drivers on YouTube, you should check out his channel. He’s got a lot of deep content about running these ubiquitous motors. Sure, we could have just linked to him showing you how to do FOC on an STM32, but “making it sing” is an expression for mastery in English, and a lot more fun besides.
There are other ways to make music with motors. If you know of any others, don’t hesitate to send us a tip.
Sounds like AI narration. Even if it’s not, I couldn’t get past two minutes.
Going from a sine wave to chords and envelopes took the project from 1 to 100 right quick.
Very impressive. It feels like a great starting point for a unique synths project, maybe by hooking the motor to a spring to serve as a reverb tank?
Your mind is going to be blown when you see what can be done with a paper cone, some wire, and a magnet!
While it has been suggested that the reproduction of audio is theoretically possible, both for immediate communications and as a recording, I remain convinced that it will only ever be a novelty enjoyed by the wealthy.
Perhaps in fifty years, the five richest kings of Europe may be communicating at a distance with speech and possess machines that can reproduce a few minutes of sound while only occupying a single room but I wouldn’t sell your telegraphy and music hall shares just yet.
I have never done this but your post has convinced me to give it a go
For sure not the same sound quality but most modern ESC can play startup music on the attached BLDCs e.g. https://www.youtube.com/playlist?list=PLwip8UXl_Wqg4FUnzJBpHO_VSBquJgiac
or the melodie editor on https://esc-configurator.com/
The Austria Railjet (ÖBB) plays also musik when leaving the station. https://youtu.be/0Cz8VaJErjA?si=8ynNKMXPnz4bDFKc
But no chords !!
Nice work.
Not really the same at all, but I’ve plugged a plain DC [b]brushed[/b] motor into a normal audio amplifier and gotten something similar
Kronk, as a drone singing it’s own theme music.
Can a BLDC on a project, running, give real alert messages?
Yep! I know there’s some common BLDC ESC firmware that will beep error codes at you with the motor.
Audio is alternating and won’t alter the velocity of the motor when summed over time. On paying attention to the closeups, you’ll notice that the rotor does not move significantly. That means that a moving motor will not stall or speed up too much if an audio waveform is superimposed on its DC supply. What will be interesting is whether the cute beeps will be able to be heard over the propellers’ WHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOSH. Maybe toroidal propellers can help there.
Pity the video didn’t show what circuitry was driving this motor, because any circuit that can play music through this can probably make it act like a servo (position and speed control) too.
Also you can change the wave form and decay curve to sound like other instruments.
Do not forget the floppy music https://m.youtube.com/watch?v=kCCXRerqaJI&pp=ygUMZmxvcHB5IG11c2lj
And I’ve found that a stereo audio amplifier makes a pretty good motor driver too! One stereo amplifier obviously can run a 2-phase stepper, but it can also run a full 3-phase BLDC, by grounding one motor leg. Bonus: it’s nice and quiet!
I don’t see how this is that impressive, it has been a feature of hobby ESCs for quite a long time now. On drones it is used for beeps at startup or beeps to help you find the drone after you crash but a lot of them do also have the feature to play a short piece of music when the drone starts up.
This makes me wonder if a balanced brushless motor driven this way could make a more versatile vibration motor than the usual offset-weight setup. Game controllers often have multiple motors of different sizes and with different amounts of offset weight to produce high-pitched and low-pitched vibration effects, maybe one motor could do the work of both, and then multiple identical motors could be combined to give even more capability.
This takes me back to the 70’s at college where I watched and listened to a chain printer play the school’s song. They also had the IBM360 run the “right” instructions to play music on a nearby radio.
Singing Winchester.
Now why couldn’t one get this to either listen to itself and noise cancel itself or even just adjust it with a pre-made phase inverted sound of the rotors to make a quieter quadcopter?
there’s nothing here. as others have said, you just feed an audio waveform into a BLDC and it’s just a low quality speaker.
there is a cool thing…not only can ESCs (electronic speed control, the interface between a radio receiver and a BLDC) sometimes play music, but a lot of them use it for their configuration as well. you move the throttle stick up and down to control its configuration process, and it plays different kinds of beeps to let you know what you’re doing so you can tell what you’re doing. in practice, it works really well for me.
making the noise isn’t an accomplishment, but making the noise for a purpose is, imo.