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

chipweinberger.com

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

#191

Post by [deleted] »

ost-ing wrote: post #189
em3rgent0rdr wrote: post #162

Earlier quoted context omitted.

> "actual regulations...emissions" yeah, and looking at their board I see they use one of "ESP32-WROOM" modules, which has the wifi & blutooth & antennae (pre-certified by Espressif for FCC, CE so itself doesn't need testing) & flash & processor (which even has its own RC oscillator), which takes care of a whole ton of difficult stuff so all the designer needs to do is plop that module down and power it up and wire s…

Im not an expert in emissions testing but pretty sure it still needs CE certification testing. The module shouldnt cause any problems providing that the firmware for the transmitter is configured properly, and is placed sanely in the enclosure, but the entire product must still undergo the relevant testing for 2.4GHz emitters. Just because you use a certified module doesn't give you a free pass.

[deleted]

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

#192

Post by jimcollinswort1 »

I've had a Jamcorder for 2 years on my digital piano, have been learning to play. Love the tracking data on the calendar and playback. I plugged it in and it's been running and updating itself perfectly the entire time. Thanks so much Chris

Part of the reason I wanted this in the first place was to have the data, a few hundred hours of all my learning and playing. At some point I or someone else will start thowing all this midi into an LLM.the jamcorder has been saving everything I've played in a very tiny amount of space with no effort by me, ultimately will be even more useful.

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

#193

Post by 8bitsrule »

chipweinberger wrote: post #2

I'll be sticking around in the comments so feel free to ask questions. AMA!

Interested. I got far emough on the site to have a couple of questions. (Maybe the answers are on the site?)

1) Does device record ALL MIDI sent to it? (Including e.g. SYSEX and non-registered parameters?

2) I edit MIDI on a Desktop (NOT a phone). a) Are sessions recorded into separate files? Named and/or dated? b) Can I inspect & load sessions from the card?

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

#194

Post by tough »

ssl-3 wrote: post #179
em3rgent0rdr wrote: post #162

Earlier quoted context omitted.

> "actual regulations...emissions" yeah, and looking at their board I see they use one of "ESP32-WROOM" modules, which has the wifi & blutooth & antennae (pre-certified by Espressif for FCC, CE so itself doesn't need testing) & flash & processor (which even has its own RC oscillator), which takes care of a whole ton of difficult stuff so all the designer needs to do is plop that module down and power it up and wire s…

The ESP32-S3-WROOM1 module is FCC certified for its own Wifi and Bluetooth emissions when used by itself. And, well -- that's certainly good. But the FCC rules cover more than just Wifi and BT, and the whole rest of the widget also needs to comply with them. Of particular interest is FCC Part 15 Subpart B, which covers unintentional radiators . The device would need to comply with Part 15 Subpart B even if it had not…

A fun fact of the CE mark, is that it's also used to signal "Chinese Export" deceptively, with the marks being almost identical beyond spacing.

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

#195

Post by TZubiri »

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.

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

#196

Post by tough »

tmp10423288442 wrote: post #188
skippyfish wrote: post #132

Hardware has a reputation for being hard for three reasons. First, it scales differently than software. It's far harder to design something you want to make a million of than something you want to make ten of. Second, it's harder to anticipate, test, and correct all the things that can go wrong on the user end. Some people will put batteries the wrong way, some will drop the device on the ground, some will connect it…

>your JS is too big, you can't ship until you get it under 50 kB Back in the glorious past, the iOS App Store either didn’t allow apps larger than 100 MiB, or at least forbade them from being downloaded over mobile connections. There’s an old blog post/Twitter thread you can find on Hacker News where an Uber engineer describes the challenges they faced in trying to keep their app under that limit. They were also rewr…

now App Store doesn't prohibit it, but it still asks you if you'd like to download an app that weights more than X mb or wait for a wifi connection to do so.

Apple UX used to be good, not anymore sadly

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

#197

Post by embedding-shape »

Grombobulous wrote: post #135
embedding-shape wrote: post #66

Earlier quoted context omitted.

> I reject the idea that programming is „just typing“, so we are very unlikely to understand each others. I'm sorry if I gave the impression I think programming is just typing. For me "programming" is the whole activity of creating software with code, you can do programming without the literal action of typing. > Writing the code and thinking about the exact logic you want to apply and all its implications are part o…

I’m just wondering why it’s bothersome that someone else doesn’t like coding with LLMs. Maybe they just like doing it the old fashioned way. You can both exist. Unless you’re getting a commission to sell LLMs to people I struggle to understand what you’re trying to achieve.

> why it’s bothersome

It's not bothersome, I'm not bothered by it at all, everyone gets (in my mind) to do things that makes sense to them. When I write comments here disagreeing with others, it's more from a "Please explain further your perspective so I can understand it, which hopefully I trigger by challenging it" view than anything else, not "You should do as I am doing things".

> Maybe they just like doing it the old fashioned way. You can both exist.

Completely fair if that is the perspective, just to re-iterate, I'm not trying to convince anyone of anything, only to understand other perspectives better.

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

#198

Post by sieabahlpark »

ost-ing wrote: post #189
em3rgent0rdr wrote: post #162

Earlier quoted context omitted.

> "actual regulations...emissions" yeah, and looking at their board I see they use one of "ESP32-WROOM" modules, which has the wifi & blutooth & antennae (pre-certified by Espressif for FCC, CE so itself doesn't need testing) & flash & processor (which even has its own RC oscillator), which takes care of a whole ton of difficult stuff so all the designer needs to do is plop that module down and power it up and wire s…

Im not an expert in emissions testing but pretty sure it still needs CE certification testing. The module shouldnt cause any problems providing that the firmware for the transmitter is configured properly, and is placed sanely in the enclosure, but the entire product must still undergo the relevant testing for 2.4GHz emitters. Just because you use a certified module doesn't give you a free pass.

[dead]

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

#199

Post by Geof25 »

skippyfish wrote: post #168
sudo_cowsay wrote: post #149

Earlier quoted context omitted.

> impossible to find because a factory in Indonesia is on fire Has that happened to you?

Not literally, but I had two projects I had to fundamentally redesign due to multi-year chip shortages in the COVID years. And we're not talking about any fancy chips.

STM32 had this problem of disappearing for years. At least I was forced to move to ESP32 and have never returned back.

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

#200

Post by PowerElectronix »

sudo_cowsay wrote: post #149
skippyfish wrote: post #132

Hardware has a reputation for being hard for three reasons. First, it scales differently than software. It's far harder to design something you want to make a million of than something you want to make ten of. Second, it's harder to anticipate, test, and correct all the things that can go wrong on the user end. Some people will put batteries the wrong way, some will drop the device on the ground, some will connect it…

> impossible to find because a factory in Indonesia is on fire Has that happened to you?

A power converter I designed 3 years ago needs redesigning because the company that made the transistors was bought out and all their packages were phased out. And they were some fucking good packages that allowed for very good cooling and very easy parallelling of transistors using both sides of the PCB.
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