logoalt Hacker News

What I learned selling 2,500 MIDI recorders: Hardware is not so hard

543 pointsby chipweinbergerlast Sunday at 10:34 AM247 commentsview on HN

Comments

erwincoumanslast Sunday at 3:31 PM

Another happy customer, bought two Jamcorder units. Not just the hardware is simple, the software as well: it just works, quietly in the background. I just had to enable daily auto-reset otherwise it eventually had issues. Whenever someone starts playing piano, it records. The iOS app is so nice, playing back on the phone or on the piano, and keeping track of total hours played and organizing favorites. Congrats, if only more projects kept things simple and useable!

knotimpressedlast Sunday at 5:33 PM

Does anyone know what kind of anti-counterfeiting techniques he used?

dvfjsdhgfvyesterday at 12:15 PM

Interesting that is has ESP32 in there - looks like it's becoming the default choice whether or not wireless is involved.

cantdutchthislast Sunday at 1:44 PM

Reading these kinds of stories always make me happy. Well done!

alancelast Sunday at 1:37 PM

Ok are you riding with two huge boxes containing all your work on an electric unicycle and I guess the hi-vis top means you're headed into traffic and the box-cords seem to be balancing at the halfway point of the boxes and this is too much anxiety for me. But hey, glad you optimized for minimalism on the PCB ♡

show 1 reply
jeffrallenyesterday at 9:29 AM

> Have a strong anti-counterfeit strategy. Don’t overlook this.

Hope we can read more about this.

MisterMowerlast Sunday at 8:56 PM

> 3. Partner with a Chinese assembly house and suppliers. Alibaba is your friend.

Oh, if that’s how you build hardware then sure, hardware isn’t hard to do at all.

Hackbratenlast Sunday at 12:34 PM

How is fulfillment not a nightmare?

show 1 reply
JoshTriplettlast Sunday at 7:48 PM

Very much appreciating the sentiment in the article.

Is it just me, or is there some kind of unusual photo editing going on in the photo at the bottom of the article? Something looks uncanny valley, related to the bottom of the box on the left side of the photo, and related to the background. Did some kind of "erase background" mechanism go wrong here?

naikrovekyesterday at 1:03 PM

the amount of crapping on the author that I'm reading bothers me.

whole lot of manufacturing experts on HN today.

elzbardicoyesterday at 12:45 PM

It's not that hardware is simple, but the fact that we have inexpensive micro-controllers that pack a giant amount of complexity and let us turn a lot of electronic problems into software problems.

Try building such a device only with non programmable TTL logic.

TZubirilast Sunday at 11:03 PM

Nice.

If I may ask for your advice on a related subject.

I have an old electric piano, it doesn't register dynamics, the strength with which I hit each note. Which is a huge bummer.

I can't think of a simple way to hack dynamics onto the keyboard, I thought of adding an additional sensor and using the time delta between touching a key and hitting the bottom, but that's not really correct, as you can hit a pianissimo key fast in staccato.

Maybe a basic spring that decreases resistance as it becomes compressed, but it might make keys quite hard, and it's not very simple to implement.

Any ideas?

Thank you.

assimpleaspossilast Sunday at 3:38 PM

>>Now, granted, Jamcorder is -- very much intentionally -- a simple device. I get that.

And let's not forget that. And let's not just follow the headline.

Greetings from a hardware engineer with decades of experience building hard things.

maxehmookaulast Sunday at 6:57 PM

This is so weird. I was in the process of trying to build something almost identical! Congrats, and good luck! I'll have to buy one now.

brcmthrowawaylast Sunday at 6:27 PM

This article did not mention anything about the prototyping process (dev board, breadboard, perfboard?). @chipweinberger, please fix.

PunchyHamsterlast Sunday at 5:55 PM

Well, hardware-wise you made equivalent of hello world project so of course it is not hard in absolute terms (not to piss on your parade, it's a very cool project, just to have point of comparison).

Just that hardware equivalent of 200K of lines of code would take far, far more time and resources and with way longer debug cycle, especially when you hit the complexity point where bodging few wires to fix the prototype gets harder and harder.

That's what people mean when they say hardware is hard - if you need to start iterating on a board and not just board's software it gets complex and expensive really quick

But it is far better than it was before - I got my 5 board prototype of similar complexity (also esp32 based) within a week, assembled board, for like $100 (and it was my design mistakes that made it so expensive, like picking screw connectors in places that could totally use far cheaper generic part JLCPCB had in stock, i just didn't know any better), just a decade ago that would probably be order of magnitude more expensive.

So yeah, for those that always wanted to build a hardware project, it's probably best time in the history to do that. Both PCBA and mechanical part got cheap and commoditized enough.

negative_zeroyesterday at 8:42 AM

As usual for these posts. No certifications. No proper markings. Probably non compliant. Will probably go unpunished.

seobot_dk1289yesterday at 1:12 PM

[flagged]

lipenghui222yesterday at 10:10 AM

[flagged]

yevhen_buildslast Sunday at 1:53 PM

[dead]

cyb3ralbertyesterday at 12:06 AM

[dead]

cushychickenlast Sunday at 5:40 PM

[dead]

mertleeelast Sunday at 2:46 PM

[dead]

glasfforddlast Sunday at 5:39 PM

[flagged]