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What I learned selling 2,500 MIDI recorders: Hardware is not so hard
- cushychicken 2mo ago[dead]
- chipweinberger 2mo agoI'll be sticking around in the comments so feel free to ask questions. AMA!
- logifail 2mo agoIs the app Apple-only?
- chipweinberger 2mo agoAndroid too! Built with Flutter. Flutter is great highly recommend it.
- rwmj 2mo agoThe number that stuck out was 200K lines of code. Can you expand on why so much code had to be written and which parts were the longest (time and/or code) and hardest bits?
- chipweinberger 2mo agoThe app is about 85K lines: device connectivity, first-time setup, syncing, MIDI playback and visualization, library management, audio/video export, and OTA workflows. The firmware is about 110K lines: MIDI recording + streaming, USB, Bluetooth, Wi-Fi, web APIs, storage, OTA updates, diagnostics, security, peripherals, provisioning, and an embedded web interface. There’s a lot required to make a full-featured product.
- lukeweston1234 2mo agoThis seems like an incredibly large codebase. Did you use an existing RTOS or something similar for this product, or was this all hand rolled?
- junon 2mo agoYeesh, please tell me you didn't write all of that yourself. Which uC is it targeting, and which language?
- cazum 2mo agoFrom the photo in the link it looks like he's using an esp32-s3. I suspect that 110k number might include the ESP-IDF libraries as well as his own code. I've written a fairly feature-complete handheld device based on the esp32-s2 and the codebase is about 9k sloc of the C I've written, but that number explodes to almost 40k sloc if I include the esp-idf's imported libraries.
- chipweinberger 2mo agoThese numbers do not include ESP-IDF :)
- bonzini 2mo agoWhat is the manufacturing tooling that you mention?
- chipweinberger 2mo ago3 main components: flashing, provisioning keys, hardware testing. Nearly every component gets tested: sdcard, clock, battery, anti-counterfeit IC, led, buzzer, the tactile-switch!
- hasbot 2mo agoHave you considered supporting other MIDI instruments like e-drums and pad controllers?
- chipweinberger 2mo agoThey should just work! You can replace the soundfont that the app uses with your own too.
- shizcakes 2mo agoWhat are some examples of good anti-counterfeit strategies? And, if you’re comfortable, which applied for JamCorder?
- etrautmann 2mo ago+1
- discordance 2mo agoReally cool project. As someone from the software side who is just getting into hardware, this is very inspiring! How did you find customers? How did you get your hardware design verified?
- msandford 2mo agoI recognize the "esp32 perched on top of a circuit board" from the picture. I've got a couple of those at my house right now, I'm on the second version of one board and the third of another. I think I'm going down a very similar road for a different product. Would you be willing to some paid advising? I'm an EE so I don't need hand-holding on the actual boards or programming, really just looking for more information on everything else around the edges. Either way, thanks for the article. It was nice to get some validation of my development process.
- iamflimflam1 2mo agoI can/try to give you some advice if you need - email is in my bio. I did a semi successful CrowdSupply project based around the ESP32S3.
- lifeisstillgood 2mo ago>>> Have a strong anti-counterfeit strategy. Don’t overlook this. Can you expand? What counterfeits do you see (literally someone selling boxes labelled jamcorder? How do you handle that? Lots of scanning amazon and sending cease desist letter?
- raphman 2mo agoThe website gives a very nice and captivating intro to the device. But why do you spell MIDI in lowercase there? > plugs into your piano via midi
- chipweinberger 2mo agoThe marketing answer: all lower-case looks modern and opinionated The real answer: I got tired of deciding what should and shouldn't be capitalized. Sounds easy but it gets ambiguous fast. I'll revisit this decision at some point. Capital letters do make reading easier.
- 8bitsrule 2mo agoInterested. 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?
- Ilya85 2mo agoWhat was the biggest mistake you made in the early days that almost killed the business?
- chipweinberger 2mo agoSpending too long on the firmware. I almost ran out of runway. I should have cut features faster. And I should have built the firmware cross platform so I could run it my local machine. Every compile + flash loop took 2+ minutes.
- stavros 2mo agoWhat was your anti-counterfeiting strategy? That sounds interesting.
- chipweinberger 2mo agoI'm using an STSAFE chip - the same IC they use in StarLink terminals. Essentially the digital equivalent of a holographic barcode. I have some other protections too. e.g. Random 128-bit per-device IDs / product-keys. iMessage uses this strategy. Maybe I'll write an article about that.
- stavros 2mo agoPlease do, that'd be very interesting. I imagine it's doable to use random per-device I'd when you're hand-flashing, but probably harder on a huge production run.
- swiftcoder 2mo agoAlmost all commercial devices need a unique ID, private key, etc burned in on the production line. For a big enough production run, you'd likely ship an HSM to the factory
- chipweinberger 2mo agoIMO it's better to ship preprogrammed ICs to the factory, so you can do your secure burning in-house.
- swiftcoder 2mo agoDepends on where the ICs originally come from. No point shipping your ICs from China -> US, flashing them, shipping them back US -> China for assembly, and then ship them China -> US again to sell
- 2mo ago
- nippoo 2mo agoHow did you navigate the world of compliance testing and certification, with all the different countries involved (FCC, UL, etc). Are there any markets you've decided not to sell to as they're not worth the paperwork?
- chipweinberger 2mo agoI chose to do FCC only and CE self-certify. If you use pre-certified radios it's not as expensive as you think. $5K should be plenty if you ask around. Just make sure you design your board so you actually pass, and don't let the labs over-sell you. They'll try to! 99.99% of cheap Chinese products you buy on Amazon don't actually have this testing done at all. So by doing any testing you're already way above them.
- iamflimflam1 2mo agoI wrote a bit about this in CrowdSupply write up - https://www.atomic14.com/2025/07/21/crowd-funding-retro https://www.atomic14.com/2025/07/21/crowd-funding-retro CE is all about self certification. The lab testing gives you the confidence to do this. It can be expensive - but Chinese test labs are very affordable and do a really professional job. There is now quite a good EU based service - https://early.smander.com/ https://early.smander.com/ I used them to get some advice early on (disclaimer, I know the founder).
- crote 2mo ago> 99.99% of cheap Chinese products you buy on Amazon don't actually have this testing done at all. So by doing any testing you're already way above them. Yeah, but those Chinese dropshippers don't have significant local presence. If they are caught doing shady stuff they'll just let their $100 letterbox company go bankrupt and start over. You, on the other hand, would actually have to pay whatever fines some regulator charges you with, because you are physically present in a jurisdiction they can apply power to. This makes self-certification a bit of a footgun: you essentially pinky promise that you fully understood all the relevant rules and regulations, and otherwise pay what in the worst case might be a hundred-thousand-euro fine. Quite a bit of a gamble! The main saving grace is of course that the authorities are way too busy to investigate some random guy selling a handful of devices from his kitchen. But get too successful, and some competitor might just decide to give them a little hint on exactly what part you missed because you didn't even know you had to comply with it.
- simonreiff 2mo agoWow, congrats on this project! Really cool. I majored in piano performance many years ago and will definitely check this out.
- bgnn 2mo agoIt's a poor take to be honest. I'm an EE with main expertise in IC design but I design a lot of the chip packages, PCBs, mechanical stuff like custom made sockets etc and write a ton of SW, be it tools for myself for development and testing, be it the firmware of the chip I'm designing or another chip I use on the board. For me it never felt like SW was the hard bit, because you can write and test it pretty immediately and pretty much for free. HW felt harder because of the tooling costs, lack of documentation and examples, things that aren't obvious at the beginning (EMI/EMC) etc etc but these are very minor compared to the actual issue: long and expensive development cycles. Now, that doesn't apply if your HW is extremely simple and just a glorified uC and rhe development time is mostly the code running on it. This is why this is such a poor take. One can argue for anything at extremes. SW can be very very complex and much harder than HW, and vice versa at different extremes.
- discordance 2mo agoI’m working on my own PCB and it’s my first time working on a hardware project. Any tips on how or where I could get my design reviewed?
- Intermernet 2mo agoI'm usually not an Ai shill, but I found Fable to be the first LLM that could actually provide useful feedback on a KiCAD PCB design. I paired it with a KiCAD MCP, but it tended to reverting to raw KiCAD scripting. If you ask it to review a PCB design, and provide feedback relevant to PCB design best practices, it will probably give you something useful. I wouldn't trust it to do a full design, but it's pretty good at finding issues. I'd add a few clauses to the request regarding checking components against JLCPCB/PCBWay/etc available components, as well as checking copper layer thickness and distances from the main components to the supporting components. I did this as an experiment on my current project and it found a bunch of minor, non-critical, but completely valid problems with my deisgn.
- connorlu 2mo agoIf you're building with KiCad then I've found the folks on the KiCad discord[1] very willing to take a look over a design and provide feedback. There's also a subreddit[2] for PCB design posting and review, but I haven't personally used it. [1] https://www.kicad.org/community/chat/ https://www.kicad.org/community/chat/ [2] https://www.reddit.com/r/PrintedCircuitBoard/ https://www.reddit.com/r/PrintedCircuitBoard/
- Hackbraten 2mo agoHow is fulfillment not a nightmare?
- chipweinberger 2mo agoIt sort of is. I'm at an annoying scale where most 3PLs don't want to deal with me yet. At the same time, it doesn't take much time at all, and is a good excuse to get out of the house!
- iambateman 2mo agoThis is cool! Thanks for sharing. What understanding about hardware did you start with, and what tools did you use to learn what you didn’t already know?
- chipweinberger 2mo agoI started with having watched ~100 hours of EEVBlog :) Electronics, PCBs, CAD, injection molding was all new to me.
- Intermernet 2mo agoI'm in the middle of my first hardware project right now and I can recommend the videos on the "Phil's Lab" channel on YT. He mostly uses Altium, but he has a few videos on KiCAD which really helped me. He also has generally good throwaway comments in his videos with regards to PCB design / component placement, as well as the order of operations for good PCB design.
- nubinetwork 2mo agoThe only problem I have with these tutorials is that they're already outdated... I don't think anyone covers kicad 10 yet, and its quite a bit different than 9. (Individual dialogs might not have changed, but where they're located etc might have)
- Echo4309 2mo agoGood to see some hardware love! Congrats on hitting 2500 units. How’d you decide to make the first jump and actually build your first prototype?
- dmd 2mo agoI've been using an Anatek Pocket Record for the past 34 years. Bought it when I was 14. That's value! https://www.izcorp.com/wp-content/uploads/pm_Pocket-Record.jpeg https://www.izcorp.com/wp-content/uploads/pm_Pocket-Record.j...
- chipweinberger 2mo agoYes I've seen a few people mention that! All of the best MIDI hardware recorders are ancient, for whatever reason. Well, apart from Jamcorder ;)
- dgellow 2mo agoWow, congrats, I remember reading your HN post. I hope you will continue writing blog posts on your journey, I expect quite a lot of software engineers would be very interested going though a similar journey now that LLMs removed most of the fun of programming. It’s neat to work on something physical for a change
- embedding-shape 2mo ago> now that LLMs removed most of the fun of programming Never understood this, was the "most of the fun of programming" the literal typing for you? For me it was about solving problems and building things, and I get to do that more now than before, and without all the literal typing.
- alabhyajindal 2mo agoDid solutions to problems just pop into your head when you were programming before LLMs? Did you not pause and think about the code you were writing before?
- embedding-shape 2mo agoMost of the time by the time I reach the problem, the solution already been thought of, yeah. The literal typing and editing was behind compared to where my mind wanted to go I suppose. But also I spend long time considering the design/architecture before even attempting to write the code, so most of the time when I was literally typing code I'd know pretty much how it should be. Unknowns-unknowns being explored as separate prototypes before solidifying on any design choices, and so on.
- t-3 2mo agoI think you just have a much narrower definition of programming. Others seem to be including the "long time considering the design/architecture before even attempting to write the code" in the programming, while you are only counting the time spent at the computer. You both agree much more thinking time than typing time is involved, just not that thinking about programming counts as programming.
- stevage 2mo agoThat's a super interesting device. Definitely pondering ordering one.
- fragmede 2mo ago> Have a strong anti-counterfeit strategy. Don’t overlook this. Sounds like a story. What parts of it can you share?
- smilespray 2mo agoYeah, I'm working on a hardware project and would like to know more about this.
- TuringNYC 2mo agoCongrats. I did want to respond to this >>> The hardest part of building Jamcorder was still, by far, the software -- roughly 200K lines of code spread across the firmware, app, and manufacturing tooling. It took over 3 years and many long nights in a pre-LLM world. >>> When compared to that, the hardware was undeniably smooth sailing. >>> For the record, I don’t think I’m special. It’s just that hardware’s reputation for being difficult is, IMO, overstated. For me, when I complain about hardware, its actually usually complaining about drivers, compatibility, underdocumented interfaces, firmware etc. If one were to put firmware and manufacturing tooling in a separate bucket, that is indeed the problem!
- alance 2mo agoOk 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 ♡
- chipweinberger 2mo agoAhah good eye. It was only 4 blocks down the road! I too was surprised by how well a single cord worked to balance the 45lb boxes.
- jauntywundrkind 2mo agoI've been wading through comments (offering upvotes) looking for comment on this photo. Excellent inclusion. Very fun. People are great!
- DavidPiper 2mo agoVery happy JamCorder customer here. I've started playing in improv shows since I bought it too, and it's nice to have those on record! It's rare that I come across a product I have literally zero complaints about, or any feedback to offer. Even my concern that it was tied to an app that might disappear one day is of course covered by the fact that it's all just MIDI files on a card. Thank you so much for making this, it's basically a perfect product for me and I love it. No notes.
- chipweinberger 2mo agoThis is very flattering. Thank you.
- benoliver999 2mo agoDitto here. I was an early customer and it's just flawless. It powers right off my piano USB so it's basically silent. If I ever get good at piano it'll be handy
- Suppafly 2mo ago>Even my concern that it was tied to an app that might disappear one day is of course covered by the fact that it's all just MIDI files on a card. I was sorta surprised when the blog mentioned it was like 200k lines of code for an app. I wouldn't think you'd even need an app for something that puts midi files on an sd card.
- chipweinberger 2mo agoThe app is not required if you access the midi files from the sd card. You don't even need to install it. The app is optional, and its for browsing your library. Think of it like the Photos app but for MIDI.
- j-bos 2mo agoInquiring minds want to know: what is your anti-counterfeit strategy or is the fact that you're keeping it under your hat part of the strategy? Also, pretty cool that you set up your website real fast. Would you mind adding your Twitter link onto the site?
- illwrks 2mo agoMy guess is that it’s on the software side partnered with the app.
- chipweinberger 2mo agoYes the anti-counterfeit is primarily app enforced (though entirely offline). I do use the firmware encryption features of the ESP32-S3, whatever that is worth, and the firmware is tied to the HSM.
- maximilianthe1 2mo agoWhat happens when app is outdated and can't be installed to current android os?
- alwa 2mo agoAre we talking about the app operationally day-to-day, or the app vis a vis the way it helps end users flash encrypted firmware images OTA to the ESP32 (like Chip alludes to in gp comment)? If there are no more app updates, presumably there are no more firmware updates either, so the flashing part probably doesn’t matter (and you can probably flash the last published image to an authentic device by other ESP32-y means if you really need to). As to the day-to-day: Pretty sure the hardware still records regular ol’ MIDI files to the SD card. The app seems incredibly well-thought-out and ergonomic but, at the end of the day, nonessential to the device’s core function. Somebody could presumably build and sell their own “MIDI Recorder Loop Nonstop Device Digital Piano Upgraded New 100%,” but it wouldn't be a Jamcorder, you couldn’t flash Jamcorder firmware updates to it just by slapping an ESP32 in a case, and the official Jamcorder companion app would not talk to it. Which… fair enough, right? For that matter it wouldn’t surprise me if somebody could write their own client for the real Jamcorder, if they felt so inclined… but with the official stack so absolutely perfect from a design perspective, why would they?
- hoppp 2mo agoThe audio hardware industry is much more easy due to the gear addict people buying up everything.
- cantdutchthis 2mo agoReading these kinds of stories always make me happy. Well done!
- Archit3ch 2mo agoI can't wait for ASIC manufacturing to become as easy as ordering a PCB.
- crote 2mo agoUnlikely to happen any time soon. The problem is mask manufacturing costs: you spend a lot to make a set of masks, but after that making the chips is incredibly cheap. Great for mass production, not so great for prototyping. And there's a lot of proprietary 3rd-party IP involved in chip production: fabs are not very eager to make that publicly available. Heck, even FPGAs are still mostly proprietary! That doesn't mean it is completely impossible, though. Fab2 (formerly Atomic Semi, of Jim Keller and Sam Zeloof fame) is trying to do exactly this by aiming at making small-scale production affordable. The trick is to replace the whole mask-based lithography with electron beam scanning: way slower, but no mask costs. But they are now targeting selling mini-fabs to R&D labs rather than offering an affordable ASIC-as-a-Service. Let's hope one of their customers makes it available to the public!
- craigjb 2mo agoWe’re at approximately where PCB pricing was 20 years ago, which _is_ a big deal: https://wafer.space https://wafer.space
- crote 2mo agoStill a few orders-of-magnitude off, though. Hobbyist electronics manufacturing has always been reasonably affordable, with the old perfboard / stripboard from RadioShack having been a staple of the hobby since forever. At-home etching was also available for the people who cared more about having cool PCBs than about having healthy lungs. The availability of cheap factory-made low-volume PCBs goes hand-in-hand with the switch towards smaller and smaller SMD parts. You don't need a professional PCB for a few THT parts, and you can always put the odd SOT part on a breakout or dead-bug solder it. But when many interesting parts started to become available only in QFN/DFN (or worse: BGA) packages, proper PCBs became the only option. Combine that with PCB factories wanting to make a few extra bucks off of their wasted board space, and it is suddenly quite attractive to hack together a quick-and-dirty ordering page for hobbyists and prototypes. No new technology needed, just a new market waiting to be served. $4 / die custom chips are indeed very attractive, but the $4000 MOQ is not. A high-school or college student just getting into electronics can afford spending $100 on a hobby project just to discover it is broken, but there is no way they can afford spending "used car" money on it. That's startup territory, or "retired Bay Area engineer" territory. Unfortunately they still run into the same basic economic problems: a wafer might be only $1000, but a set of masks is closer to $100k. This means you want to maximize the number of wafers, with ideally each wafer only containing a single copy of each chip. But even if you assume they just fill a reticle to the absolute maximum with unique chips (let's call it 40 unique designs) and fit, say, only 25 copies on a wafer, that's still only 40 wafers, so $2500/wafer in one-off costs - completely dwarfing the actual wafer itself. For hobbyists you want a process closer to $10k / wafer with zero mask costs. Fit the same 1000 chips on there as before, and you can now sell people 5 copies of their chip for $50. That's a completely different game!
- yevhen_builds 2mo ago[dead]
- bloggie 2mo agoHardware isn’t hard if the hardware is easy? There’s very few components, one of which is a pre made module, and it took 3 years to make essentially a text logger.
- Fordec 2mo agoAnd the RF is a pre-certified module. Of course hardware is easy when you've offloaded the hard part to the supplier. Not to mention, a three year turn around? For this? Three months, six max with mistakes and reworks would be industry expectations "pre-LLMs". Everything is easy when you have 6x to 12x the timescale your competitors expect.
- Archit3ch 2mo ago"Do things that don't scale!" is standard founder advice for a reason. The fact that no one else has put in the work means you get to sell $150 MIDI recorders... for a while. Which, fair enough, might just sustain a one-person business.
- deleted 2mo ago[deleted]
- stefan_ 2mo agoYeah I mean this hardware isn't hard because its a fricking breadboard. (Although I spy an SD card slot, a favorite of the "hardware isn't hard" faction that will explode in their face)
- starky 2mo agoSeriously, microSD cards are the second worst hardware component to have to deal with (first being labels). For being a "standard" you end up with cards that are subtly but significantly different from each other, the slots are ALL poorly designed, and microSD cards are just inherently unreliable. Plus with the current flash shortage, the major manufacturers don't care at all to support any issues with the product.
- cmicali 2mo agoCongrats on an impressive achievement and milestone. This is a great outcome, great work, and an indication of how far the hardware industry/tooling has come. This feels though a little to me like building a simple SaaS service, and deploying it on a managed cloud service, and concluding all software is really easy! This project is near to (if not at) the easy end of the hardware product difficulty/complexity spectrum. Some great choices were made to keep it simple and therefor easy. An alternate take-away: "If you keep things simple, hardware doesn't have to be as hard"
- mosura 2mo agoThat underrates the difficulty in keeping things simple. It is mentioned elsewhere here that a lot of time was burned on unused firmware features. It takes surprising discipline to cut stuff and still deliver.
- jrflo 2mo agoAgreed. At someone who works primarily in hardware, it is definitely hard. A midi-to-bluetooth recorder is practically a software project in a fancy box. There is very little physical complexity to deal with here, which is what makes hardware difficult- the interaction between firmware and the "real world". Congrats though, making a half-million a year business is a massive accomplishment! The headline just irked me a bit, haha (but, it got my attention, so I guess you win there)
- chipweinberger 2mo agoI don't entirely disagree. Just one sample point. But there are certainly much more simplistic hardware products out there. I'm often envious of them. Here's a good example: https://duckduckgo.com/?q=brick+smartphone+blocker&ia=web https://duckduckgo.com/?q=brick+smartphone+blocker&ia=web
- missinglugnut 2mo agoHey man, you made a successful product, wrote a great article, and are now getting attention for it. You don't need to respond to every person who wants to nit pick at your title :) I think there's a lot of people talking past each other here. Sourcing parts internationally, preventing counterfeiting, slow iteration time, inventory management...all this logistical stuff is hard enough that the conventional wisdom in the software business world is to never attempt it. You're here presenting a counterexample and that's wonderful. The people criticizing aren't talking about this though, they are talking about whether logging digital inputs on an esp32 counts as a real hardware project and they act as if you've insulted their expertise in [signal processing/antenna design/insert specialty here]. You didn't do that, most of us know you didn't do that, but the word "easy" sets a lot of engineers off. Just ignore the noise and keep writing great articles. My personal request, if I may - I'd like to hear how you did injection molding since I always assumed that was out of reach for small business.
- NDlurker 2mo agoCongratulations! I bought one after reading your post on here announcing it. It's fun to mess around on my keyboard and be able to go back and listen to what I played. Great for learning
- patrickdet 2mo agoI would be curious what “ Have a strong anti-counterfeit strategy.” looks like in practice
- brookst 2mo agoGreat write up! Why custom MIDI connectors of all things? What requirement couldn’t be met off the shelf?
- chipweinberger 2mo agoNot technically custom, but made to order (I gave them a spec sheet). If they had reasonably priced connectors on LCSC or DigiKey, etc, I would have used them!
- Graziano_M 2mo ago> Have a strong anti-counterfeit strategy What is this strategy? You're building this in China, it's already over.
- connicpu 2mo agoI would assume the 200K lines of software and the firmware is presumably flashed after receiving the product from the assembly house.
- HNisCIS 2mo agoThe anti counterfeit strategy is that the volumes here aren't worth it for someone to clone, even if the board and code are dead simple. These niche hobby products are usually reasonably safe because they rely on community network effects, becoming the darling of a random subreddit or discord group and people aren't going to save $20 to get some device of dubious origin.
- mertleee 2mo ago[dead]
- arthurwolf 2mo agoI don't know what the timeline is here, but to me this sounds like he either got lucky, or he's in the grace period when you begin a project and the strong enthusiasm for it, and the fact people are not seriously trying to copy it yet, work together to make everything just that much easier...
- erwincoumans 2mo agoAnother 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!
- scottydelta 2mo agoI am also on a similar boat. After writing softwares for almost 13 years now, I am now working on a privacy focused and universally compatible casting device. Would love to talk to you more about hardware supply chain issues and challenges. Meanwhile if anyone is tired of their smart TV being a spyware or showing ads, I would love to talk to you. This is what I am building: https://soljacast.com https://soljacast.com
- assimpleaspossi 2mo ago>>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.
- mietek 2mo ago> Have a strong anti-counterfeit strategy. Don’t overlook this. Would like to see this highly non-obvious point expanded upon.
- BloodyIron 2mo agoHow did you market it? I'm trying to get into my own production stuff and I don't want to participate in the parasitic Amazon or overcrowded Etsy ecosystems. Looks like you're doing sales through your own website, which I want to do myself. But I haven't yet figured out how to bring legit traffic to my own website. I don't have money to throw at advertising and that's a minefield of fake traffic anyways. Any advice to share please?
- dofm 2mo agoA question: Are you still below any significant scale thresholds and are there any you dread crossing? I ask this because I tend to find things are simple until they are not. e.g. it's easy to write an e-commerce platform until you have to deal with shipping, duty, tax, tax on shipping, etc., for multiple countries. There are scale thresholds I am aware of in hardware that I have not yet run up against. For example I am using Free software, but I am aware that with commercial CAD you can cross over price tier thresholds. Or for another example there are sales quantities where with electronics you might end up needing compliance testing, consumer safety testing etc. Which ones haven't you crossed yet that you expect to have to navigate?
- Archit3ch 2mo agoHaving too many orders is a good problem to have (unless it gets cloned). Worst case, you pay an external contractor to sort compliance/fulfillment/whatever.
- dofm 2mo agoI guess, though I am not sure that this truly is the worst case, if some new compliance thing required a redesign or worse. You hear about firms that go over certain thresholds, get noticed and then find out that their production facility is no longer "small" or exempt for example. Some amount of defensiveness in planning and design can mitigate but I'm interested to know if there are thresholds I didn't know about.
- analog31 2mo agoI make a physical product, akin to a guitar pedal. Possibly the most scary threshold would be if I'm successful enough that I need to quit my day job, but not successful enough for the business to support my family. That's kind of a no mans land where I don't want to be. Another similar threshold would be having to hire people, which changes the complexity of the business in a variety of ways.
- crote 2mo agoYeah, hardware is indeed not too hard if you have a trivial hardware project and ignore all the hard stuff. Complexity-wise this is probably the easiest board one could imagine. It's an off-the-shelf MCU module, a 1:1 copy of the MIDI circuit from the specification, and some ports wired straight to the MCU. Throw in a trivial I2C-connected RTC and HSM for good measure. You could probably design this in an afternoon. But indeed: that is a good thing. Not everything has to be complicated, and plenty of people are willing to pay for simple products. On the other hand: what is the cost for that? The USB-A Host port has ESD protection, but as far as I can tell MIDI Out and SD do not. Sooner or later this will result in some static-prone user frying their expensive board. Have you got a proper Customer Support / aftersales pipeline yet? How many units did you reserve for warranty replacement? Luckily you've got a huge margin, so a few replacement boards shouldn't bankrupt you. Similarly, the MIDI ports seem to be using low-double-digit series resistors for the MIDI Out current loop - in 0402 form factor. As the spec says: short the port and they'll draw over 0.5W, which a 0402 can't dissipate. To be fair, the exact circuitry is a bit hard to tell from the image, but will this mean they'll catch fire? The AMS1117 is also an interesting choice. It's a classic option so it is often seen in beginner tutorials, but it is absolutely terrible[0], and with the capacitors used you shouldn't be surprised to eventually run into stability issues. It might work Just Fine for 99% of units, but the 1% will have weird undiagnosable heisenbug issues. From a UX perspective I'd also question the use of a coin cell battery for the RTC: it'll eventually run dry or even start leaking. A supercap would've been a more durable and convenient option - especially considering the "always leave it plugged in and forget it" use case. Or, if you need a battery anyways: go for li-ion so it can be used on-the-go. Similarly: USB-B for Power In in 2026? That's just lazy. USB-C is trivial to add with a 5-minute-guide and would've been cheaper. The USB-A Host port is just about excusable, though: doing that in USB-C is a bit harder. And the Power In port not being usable for a connection to a host PC and telling people to buy some sketchy adapter on Amazon? Understandable considering the MCUs peripherals, but a disappointment. And then there's the elephant in the room: certification. It seems like you just... didn't? Which is understandable for a small hobby project! But making it EMI/EMC compliant is by far the hardest part of designing market-ready products. You can't just completely ignore all the stuff involved in making it compliant with FCC/CE/UKCA/whatever rules and call it "not so hard". It's the difference between baking a pie for your birthday party, and opening a bakery. Your hardware project wasn't hard because you've only done the easy stuff. And kudos for shipping - many people don't make it even remotely this far. Especially using an injection-molded housing is quite the achievement! The startup costs for that make it a real showstopper for many small-scale projects, and making mistakes can easily bankrupt you. But this is where the actual adventure starts: scaling it to 25k / 250k units. You basically have to start from scratch and do 10x as much work. Meanwhile, China is pumping out $10 clones for your $250 recorder. Sure, you put DRM in it, but is your software moat really wide enough to protect you? Many congratulations on your achievement, but please understand that writing this blog post is almost naively premature. The hard part hasn't even started yet. [0]: https://www.reddit.com/r/esp32/comments/1m7ne4i/psa_avoid_using_the_ams1117_ldo_for_esp32_projects/ https://www.reddit.com/r/esp32/comments/1m7ne4i/psa_avoid_us...
- yanslookup 2mo agoThis is not a criticism but I am curious about what the trade offs are in terms of cost/bom etc of using usb-c. I found it surprising that that wasn't a given in 2026,curious where it hasn't caught up as an option.
- Kirby64 2mo agoAssuming this is just standard 2.0 speeds, it should be nothing. It adds a slightly more expensive connector and 2 resistors… and that’s it.
- bloudermilk 2mo agoThese are the hardest cuts to make in design, being so incremental, but they add up!
- chipweinberger 2mo agoIf you consume power over USB-C, 2 resistor are enough. But for providing power over USB-C, you generally need a dedicated IC to handle VBUS switching. It wasn't worth it. Also, once you ship a consumer product with a USB port on it, you'll realize a lot of people really don't understand how USB works, and USB-C doubly so. Square holes for square pegs goes a long way.
- Kirby64 2mo agoSure, but your power input should be a USB-C. No reason to use the clunky USB-B for that. Labeling as Power In and leaving a regular USB A for the output seems fine to me. Given that most older keyboards use USB-B for their input, A is a perfectly fine solution and solves the “input vs output”.
- crote 2mo agoOP mentioned in another comment that a decent chunk of users is elderly, and C-to-B cables (albeit rare) do exist, so confusion isn't impossible. I personally really don't like it in a world where everyone has USB-C power bricks readily available and USB-B cables are dying out, but considering the user base it is not an entirely unreasonable design decision - for now.
- peteforde 2mo agoVery happy to hear about your success! I'm curious to hear more about your anti-counterfeit strategies beyond just enabling encryption. I'm curious if you feel like anti-counterfeit and open source firmware are mutually exclusive. I made the choice to embrace an open firmware approach on my project while keeping the hardware closed, while knowing that if someone tries hard enough they can completely reverse engineer if they put their mind to it. Desoldering caps and x-raying PCB layers etc. I'm also very curious to hear more about your adventure in injection molding. What starting resources do you recommend, how much did it cost? Would you do it the same way today, or have the recent innovations in 3D printing forms for injection molding present superior paths? Finally, I'd love to hear about your certification process. What certs did you get, how much did it cost, what were the gotchas?
- chipweinberger 2mo agoWill do a write up on injection molding and anti-counterfeit!
- deleted 2mo ago[deleted]
- smallpipe 2mo agoSounds great! Can I subscribe to an RSS feed/mailing list?
- elictronic 2mo agoYou don't need an X-ray for a board this simple. Every component has well defined input and outputs. Give a mildly competent freshman EE student or high quality high school student you could have the board recreated in a few days. Low product quantity and low quality/fake products resold on amazon from AliExpress are the biggest roadblocks at this point. The juice isn't worth the squeeze.
- peteforde 2mo agoRight... except I'm asking so that I can apply his techniques to my PCB, which you know nothing about.
- knotimpressed 2mo agoDoes anyone know what kind of anti-counterfeiting techniques he used?
- glasffordd 2mo ago[flagged]
- hateful 2mo agoI have a old keyboard (Ensoniq SQ1-Plus) where the battery doesn't work right (even when changed) and I was going to put ML Studio on a Raspberry Pi or Mini PC with a USB MIDI device to record. But this thing is exactly what I'm looking for. When I want to record for real, I'm going to use my DAW. But I want a way to quickly record tracks and this looks pretty great.
- skippyfish 2mo agoHardware 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 to some vintage equipment you have never seen in your life, etc. And third, there are just more failure modes in an unfamiliar domain - sometimes, your code will intermittently crash not because you have a software bug, but because you put the decoupling capacitor too far from the chip. Or, just as you finish your design, the chip you designed it around becomes obsolete, or impossible to find because a factory in Indonesia is on fire. Another complication is that at least in theory, if you're selling electronics, there are actual regulations and third-party testing that needs to happen, and if you fail emissions, you might have to redo your design from scratch. Imagine we had that for software - "your JS is too big, you can't ship until you get it under 50 kB". So, I'm happy for the author, but I think he had an outlier experience. When you look at Kickstarter stories, people repeatedly stumble over this. Manufacturing / cost difficulties, supplier issues, reliability issues, etc.
- mamcx 2mo agoAND shipping.
- dabinat 2mo agoShipping physical products can open you up to more fraud, because once it’s in the mail, it’s in the mail. The customer can say it never arrived or claim their card was fraudulently used in order to keep using the product for free. Whereas with a SaaS you just disable their access.
- marysol5 2mo agoAnd also logistics is a race to the bottom, everyone is competing to get more and more packages through the system, and the customers are demanding lower and lower prices. So there's a fair amount of stuff that just doesn't make it there, there's a whole business now on re-selling non-delivered packages. And with that also comes the services, the reason they leave it at the door, or in the bin, or yeet it onto the roof. Is because there's no profit margin anymore for the delivery person to wait 30s each time for someone to answer.
- jstummbillig 2mo ago> Have a strong anti-counterfeit strategy. Don’t overlook this. Would love to hear more on that but I suppose the omission is not an accident.
- PunchyHamster 2mo agoWell, 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 $100 (and it was my design mistakes that made it so expensive, like picking screw connectors in places that could totally use far cheaper generic part JLCPCB had in stock, i just didn't know any better), just a decade ago that would probably be order of magnitude more expensive. So yeah, for those that always wanted to build a hardware project, it's probably best time in the history to do that. Both PCBA and mechanical part got cheap and commoditized enough.
- 999900000999 2mo agoVery very cool! It’s actually not hard to hack this together as a .net application and run it on a laptop, but I suspect your target market has a bit of money to spend. Learning piano is already largely an upper middle class active and after that what’s another 200$ or 300$. A higher end digital piano is easily over 2k. Making sure your target market has money is the key take away. Not sure if this is in scope, but I’d love an easy way for the community to share midi files. I can somewhat do very basic piano progressions, but I still can’t play well. I’d be grateful if someone would share midi files for me to plugin to my music software. Of course I’d provide full credit
- brcmthrowaway 2mo agoThis article did not mention anything about the prototyping process (dev board, breadboard, perfboard?). @chipweinberger, please fix.
- desktopentree 2mo agoFrom a financial perspective, what were your biggest challenges? What was the working capital cycle like? Were you forced to do a certain level of minimum order quantities and did the cash constraint limit other decisions?
- chipweinberger 2mo ago500 units was my first run, and it worked out really well. None of the suppliers complained about that order size. I recommend starting with a smaller quantity until you've validated the market. The "economies of scale" between 100, 500, or 1000, units are not all that dramatic. Perhaps 30% cost difference. I was originally planning to do 4000 units as my first run. Boy I'm glad I started to run out of money and cut it way back. That would have been way too much as a first run.
- neuralkoi 2mo agoI hope the author can break down the recommendations in a future post. I'd love to learn how to build this kind of hardware (what tools are needed), how to iterate on the results, how to find a supplier. Also it'd be interesting to know what the author means by having an counterfeit strategy.
- maxehmookau 2mo agoThis 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.
- ChrisMarshallNY 2mo agoAs always, "It Depends™". There was another post, a year or two ago, about someone that really tried to manufacture a webcam, and gave up. I spent my career at hardware companies. Glad this worked out, but past performance is no guarantee of future success...
- JoshTriplett 2mo agoVery 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?
- starky 2mo ago>But for me the take away still is: “hardware is as hard as you make it”. I dislike this statement. Hardware is as hard as the product dictates it needs to be. A 25 component PCBA and a clamshell of 2 injection molded parts is about as simple of a product as you can make. Heck, most people would just buy an off the shelf clamshell for that type of product. That doesn't work for the vast majority of products, building a product with 20 COTS parts plus 60 custom tooled parts, and 4 complex PCBAs is what is hard. Getting everything to fit together, pass testing, arrive on time from dozens of suppliers, etc. it where the complexity comes in. Then consider that hardware is cash intensive, you need to pay ahead of time for all the tools, you need to pay to buy the individual parts and warehouse them somewhere while you build the products you hope are going to sell. If something goes wrong there, then your expensive parts are just sitting there waiting for replacement components before you can ship. Then even when you ship, that revenue goes into buying the next round of parts you are going to receive in 3 months. This is where many hardware projects fail as they run out of cash before the project breaks even.
- torginus 2mo agoThis. A decade ago, during my summer internship in the first year of college, I got put on a hardware project, basically designing a remote monitoring device for a telco. I wrote the software, and my friend designed the PCB for the digital side. Basically I had to be a decent C programmer, and read the datasheet for the MCU we were using (which was way more work than using something like an ESP, but still). My friend had to lay stuff out on the PCB and place secondary components according to various application notes. Overall not simple, but not rocket science. On the other hand, the guys doing the analog daughterboard were industry veterans with decades of experience. They had a million concerns, from signal integrity, to voltage protection, back-EMF, etc. I was not even near the ballpark of that skill level. Later on, I worked on more complex HW projects, stuff with FPGAs, DRAM integration and 8 layer PCBs, where you had to run full electromagnetic simulations because when you run at 1+ GHz, suddenly signal propagation is not instant, and traces behave like antennas. I also did software there (a smaller slice of it this time), but there was an army of engineers working on the whole project which took a year, and not a second of it was spent in vain.
- 2mo ago
- MisterMower 2mo ago> 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.
- dimatura 2mo agoI think "hardware is as hard as you make it" would've been a better title. The author made the smart decision of keeping things very simple on the hardware side, and that happened to be possible for the kind of product he wanted to make. Interestingly I've heard a very similar story and sentiment about hardware vs software from another single-person maker (also a software engineer by trade) of a hardware product, also in the music space. And this one was comparatively a more complex product on the hardware side, and did face some supply challenges during covid and tariffs, forcing at least one redesign and price raise. But in both cases, I'd say they made smart choices about keeping the hardware simple. By not pushing the envelope on that front they gave themselves the freedom to invest a lot of time and effort into the software. But not every hardware product is like that (which the author also does acknowledge).
- grenran 2mo ago> strong anti-counterfeitting strategy The reality for a product at this scale is that nobody is going to spend the time or money to copy it.
- jimcollinswort1 2mo agoI'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.
- TZubiri 2mo agoNice. 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.
- JimsonYang 2mo agoI thought 'hardware is hard' is a VC statement to apply a broad stroke for why its hard to make succesful hardware companies (that gives 100x returns) For reasons other commentors have already mentioned-scale, logistics, revisions. And for reasons they havent mentioned-cash flow
- cyb3ralbert 2mo ago[dead]
- iamjackg 2mo agoLong time customer! I bought one after your original post on HN. Congrats on the milestone. Honestly, it's such a good product and I'm such a bad and inconsistent piano player that I completely forget it exists for months at a time. Then I remember about it, open the app, and everything is there: my attempt to figure out a song, my kids smashing the keys as hard as they can, my cat walking across the keyboard. It's such a joy.
- mune2gu-chan 2mo agoLove the breakdown here. It's refreshing to see someone build a physical device instead of wrapping everything in another app.
- Max-q 2mo agoThe article doesn’t mention certification, which is expensive and demanding, but required for any product containing a radio to be legal to sell.
- aleph-z 2mo agoCongrats! Happy for your success. Your mix of ingredients is impressive (the hardware alone is probably simple). Your product idea came from actual personal need (validation!), and you are able to tie the hardware to your software to widen the moat -- which is great. Your anti-counterfeiting tech hopefully / probably prevents your Chinese manufacturers / suppliers / related entities from free-riding on your work. (If your volumes start hitting say 50K+, things may change, you may be entering dangerous territory then, so I'd suggest you spend some time on beefing up the moat). Good luck towards 10K volume!
- bjt12345 2mo agoHardware's reputation derives from the reality that a lot of companies spin out the hardware before the software is even written - so all hardware bugs have to get fixed in software.
- negative_zero 2mo agoAs usual for these posts. No certifications. No proper markings. Probably non compliant. Will probably go unpunished.
- SunboX 2mo agoHardware is hard! Because of certifications and organizations like the WEEE. There are many different acts for electronic devices world wide. In Germany you have to spend about $ 20k per month even if you did not ship any product yet - just for regulations, certificates and things you have to register for to be able to sell a electronic device. That makes hardware hard! The manufacturing and packaging is the easy part.
- jeffrallen 2mo ago> Have a strong anti-counterfeit strategy. Don’t overlook this. Hope we can read more about this.
- marysol5 2mo agoVast majority of the hardware, especially as it's running on ESP has already been done for you >Assembly is just a single screw, for a single PCB. The injection mold has generous draft, no slides. Says everything
- lipenghui222 2mo ago[flagged]
- dvfjsdhgfv 2mo agoInteresting that is has ESP32 in there - looks like it's becoming the default choice whether or not wireless is involved.
- elzbardico 2mo agoIt'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.
- naikrovek 2mo agothe amount of crapping on the author that I'm reading bothers me. whole lot of manufacturing experts on HN today.
- seobot_dk1289 2mo ago[flagged]
- jtesp 2mo agowas it easier than when you took an open source repo https://pub.dev/packages/flutter_blue https://pub.dev/packages/flutter_blue and renamed it to plus https://pub.dev/packages/flutter_blue_plus https://pub.dev/packages/flutter_blue_plus to charge $3,000 to use it commercially? was that another life goal? which was more profitable? how has https://pub.dev/packages/universal_ble https://pub.dev/packages/universal_ble affected your sales since the open source community revolted?