<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Hacker News: kaipereira</title><link>https://news.ycombinator.com/user?id=kaipereira</link><description>Hacker News RSS</description><docs>https://hnrss.org/</docs><generator>hnrss v2.1.1</generator><lastBuildDate>Thu, 09 Apr 2026 09:20:31 +0000</lastBuildDate><atom:link href="https://hnrss.org/user?id=kaipereira" rel="self" type="application/rss+xml"></atom:link><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>Thanks so much!</p>
]]></description><pubDate>Mon, 06 Apr 2026 15:32:52 +0000</pubDate><link>https://news.ycombinator.com/item?id=47662244</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47662244</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47662244</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I built a tiny LLM to demystify how language models work"]]></title><description><![CDATA[
<p>This is so cool! I'd love to see a write-up on how made it, and what you referenced because designing neural networks always feel like a maze ;)</p>
]]></description><pubDate>Mon, 06 Apr 2026 05:22:31 +0000</pubDate><link>https://news.ycombinator.com/item?id=47657270</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47657270</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47657270</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>We ordered the PCB's and badges separately, but it's extremely easy to assemble, you just attach the eink on using the FPC connector and the badges are already in a complete setup of the hardware if you get PCBA.<p>You can make it more fun on yourself if you want to assemble them by hand and it's probably a bit cheaper, and JLC will ship to pretty much anywhere in the world.</p>
]]></description><pubDate>Sun, 05 Apr 2026 16:16:38 +0000</pubDate><link>https://news.ycombinator.com/item?id=47650907</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47650907</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47650907</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>Yeah the RP2040 is a bit overkill, but it's really cheap to get from JLC, easy to prototype FAST and easy if anyone wants to reference the design and create/program their own badges.<p>I have been looking at some other MCU's like the CH32 for future projects, so if you also have any suggestions for other ones, I'd love to hear them!</p>
]]></description><pubDate>Sun, 05 Apr 2026 15:40:27 +0000</pubDate><link>https://news.ycombinator.com/item?id=47650521</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47650521</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47650521</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>I used <a href="https://eds.st.com/antenna/#/" rel="nofollow">https://eds.st.com/antenna/#/</a> to get an antenna that fit with a target inductance of 4.7uH and then used <a href="https://github.com/nideri/nfc_antenna_generator" rel="nofollow">https://github.com/nideri/nfc_antenna_generator</a> to create the footprint which I slightly modified for the board! You can read a bit more about it in the journal (JOURNAL.md)!<p>It was really satisfying to get everything working (especially the NFC because I've found RF to be a bit tricky), but the eink logic was actually a bit of gamble, because I broke my only eink while prototyping so the production batch was the first test of the driver. So always carry spare components when designing prototypes!</p>
]]></description><pubDate>Sun, 05 Apr 2026 02:50:11 +0000</pubDate><link>https://news.ycombinator.com/item?id=47645704</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47645704</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47645704</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>So the eink holds its state once it’s programmed so you do need an initial program of the badge through USB-C, and then the NFC uses passive RF harvesting.</p>
]]></description><pubDate>Sun, 05 Apr 2026 00:49:59 +0000</pubDate><link>https://news.ycombinator.com/item?id=47645076</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47645076</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47645076</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I made open source, zero power PCB hackathon badges"]]></title><description><![CDATA[
<p>The total ended up being about $10/badge for 60 (5 for badge, 5 for eink), and we made the mistake of not ordering enough, so we ordered a couple more that were about $1 more expensive each. We bought all the badges from JLC and the prod files are in the repo if you want to see how much they come to in higher order quantity!</p>
]]></description><pubDate>Sat, 04 Apr 2026 23:16:13 +0000</pubDate><link>https://news.ycombinator.com/item?id=47644550</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47644550</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47644550</guid></item><item><title><![CDATA[Show HN: I made open source, zero power PCB hackathon badges]]></title><description><![CDATA[
<p>I love getting cool swag from hackathons and I also love designing PCB's, so when my friend asked me if I would design hackathon badges for a large game jam in singapore, I was absolutely down!<p>The theme of overglade was a "The game jam within a game", pretty cool concept right! High schoolers from around the world were flown out to the event by hackclub after they spent about 70 hours designing their own game.<p>These badges needed to be really cheap and simple, because we were going to manufacture about a hundred in a pretty limited amount of time. I went with a zero-power approach, which means sticking with e-inks, and I decided to include NFC if the organizers wanted to introduce it into the roleplay of the event, and so participants could add their website or github if they so choose!<p>I used an RP2040-based architecture because it's really easy and cheap to get on the first try, and then added an ST25 passive NFC tag which was really simple to configure. The badge is in the shape of a ticket, because you got a "ticket" to the event after spending a lot of time designing games to qualify! 20 GPIO's are broken out onto the edges if you're ever in a pinch at a hackathon, and I wanted the badges to feel really fun so there's a lot of art designed by various people in the community!<p>The badge worked really well and I learned quite a lot in the process. My takeaways are to manufacture a BUNCH of extra badges, because some will end up breaking; to think about your PCB in 3D, because one of the inductors was a bit tall and caused more badges to break; and to have a strong vision of your final product, because it really helped me to create something unique and beautiful :D<p>I like to journal about all my projects, so if you'd like to read my full design process, feel free to take a look at my journal (<a href="https://github.com/KaiPereira/Overglade-Badges/blob/master/JOURNAL.md" rel="nofollow">https://github.com/KaiPereira/Overglade-Badges/blob/master/J...</a>). If you also have any questions or feedback, I'd be happy to answer them!</p>
<hr>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=47639303">https://news.ycombinator.com/item?id=47639303</a></p>
<p>Points: 158</p>
<p># Comments: 18</p>
]]></description><pubDate>Sat, 04 Apr 2026 14:20:21 +0000</pubDate><link>https://github.com/KaiPereira/Overglade-Badges</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=47639303</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=47639303</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>Oh wow, I've never actually heard about the Lemontron, I'll definitely take a look at it for inspiration!</p>
]]></description><pubDate>Tue, 16 Dec 2025 17:24:37 +0000</pubDate><link>https://news.ycombinator.com/item?id=46291314</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46291314</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46291314</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>I also did forget to mention, but this project is OSHWA certified too :D<p><a href="https://certification.oshwa.org/ca000068.html" rel="nofollow">https://certification.oshwa.org/ca000068.html</a></p>
]]></description><pubDate>Tue, 16 Dec 2025 14:27:42 +0000</pubDate><link>https://news.ycombinator.com/item?id=46288897</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46288897</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46288897</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>Routing is honestly one of my favorite parts of making a PCB, there's something about the feeling of understanding exactly what each trace is doing that I find exhilarating.<p>The problem with most AI powered tools is that they don't understand the context of your board, which is absolutely crucial for routing. Like so-and-so trace could be switching really fast and an AI powered design tool wouldn't understand that and wouldn't route it properly. Or like power for example, different things have different power requirements and I feel like we're not at the point where these tools are referencing every datasheet on the planet to figure out trace/fill sizes and whatnot.<p>There's also some concepts I don't think these tools can wrap around quite yet. For example, minimizing loops, consistent ground planes, proper impedance control, and just all of these factors lead to an inferior board.<p>Not saying that humans are perfect and understand all of these too, I just feel like if you understand what's happening with your board, you can do a much better job.<p>At the end of the day, you'll be spending more time fixing the mistakes, which are actually pretty hard to spot without checking every single trace sometimes, then actually just routing it yourself, but maybe one day we'll get there!<p>I'd love to hear some other takes though ;)</p>
]]></description><pubDate>Tue, 16 Dec 2025 14:21:36 +0000</pubDate><link>https://news.ycombinator.com/item?id=46288807</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46288807</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46288807</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>I'm probably going to run Marlin just because it would be the first 3D printer I've actually made and I've heard it's more beginner friendly. I think Klipper also needs a dedicated host like a Pi which is a bit more overheard I don't want to worry about, but I'm open to exploring any type of firmware!</p>
]]></description><pubDate>Tue, 16 Dec 2025 13:53:26 +0000</pubDate><link>https://news.ycombinator.com/item?id=46288496</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46288496</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46288496</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>4 layer boards actually make it easier instead of more advanced in my opinion. You can have a dedicated ground and power plane which makes routing much simpler, and the fields are much easier to predict.<p>It's also just double the price, so I can get 4 layer boards for like $8 from JLC and it just makes everything much more easily.<p>You still do want to build up to it though, I made a macropad, then a keyboard,  and then made this, so it's definitely not just an immediate jump, but I built those 2 projects within the span of a couple months!</p>
]]></description><pubDate>Tue, 16 Dec 2025 00:05:46 +0000</pubDate><link>https://news.ycombinator.com/item?id=46282863</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46282863</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46282863</guid></item><item><title><![CDATA[New comment by kaipereira in "Show HN: I designed my own 3D printer motherboard"]]></title><description><![CDATA[
<p>That's a really cool idea!<p>I have a couple idea's on how I wanted to do it:
- Belt printer fitted into a briefcase (the harbor freight case form factor would be good for that!)
- Positron style
- Maybe mess around with double four-bars<p>Making it self-contained with a battery is also a really cool concept I'll have to explore!</p>
]]></description><pubDate>Tue, 16 Dec 2025 00:01:39 +0000</pubDate><link>https://news.ycombinator.com/item?id=46282825</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46282825</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46282825</guid></item><item><title><![CDATA[Show HN: I designed my own 3D printer motherboard]]></title><description><![CDATA[
<p>3D printing is such a fascinating field of technology, so a couple months ago, I decided to take a deep dive and learn how they actually work!<p>This took me to one of my very first PCB projects, a small, cheap, 3D printer motherboard. While it's not the most cutting edge board, I learned a lot and I fully documented my process designing it (<a href="https://github.com/KaiPereira/Cheetah-MX4-Mini/blob/master/JOURNAL.md" rel="nofollow">https://github.com/KaiPereira/Cheetah-MX4-Mini/blob/master/J...</a>), so other people can learn from my mistakes!<p>It runs off of an STM32H743 MCU, has 4 TMC stepsticks with UART/SPI configurations, sensorless/endstop homing, thermistor and fan ports, parallel, serial and TFT display connectors, bed and heater outputs and USB-C/SD Card printing, all in a small 80x90mm form factor with support for Marlin and Klipper!<p>Because it's smaller and cheaper than a typical motherboard, you can use it for smaller/more affordable printers, and other people can also reference the journal if they're making their own board!<p>If I were to make a V2, I would probably clean up the traces/layout of the PCB, pay more attention to trace size, stitching and fills, BOM optimize even further, and add another motor driver or two to the board. I also should've payed a bit more attention to how much current I would be drawing, and also the voltage ratings, because some of the parts are under-rated for the power.<p>I'm still actively refining it and fixing up some of the mistakes, but I plan on using this board to make a tiny foldup 3D printer I can bring to hackathons and 3D print on the go!<p>The project is fully open source, and journaled, so if you'd like to check it out it's on GitHub (<a href="https://github.com/KaiPereira/Cheetah-MX4-Mini" rel="nofollow">https://github.com/KaiPereira/Cheetah-MX4-Mini</a>)!<p>I absolutely loved making this project and I'd love to hear what you guys would want to see in a V2!</p>
<hr>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=46174949">https://news.ycombinator.com/item?id=46174949</a></p>
<p>Points: 127</p>
<p># Comments: 40</p>
]]></description><pubDate>Sat, 06 Dec 2025 17:21:03 +0000</pubDate><link>https://github.com/KaiPereira/Cheetah-MX4-Mini</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=46174949</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=46174949</guid></item><item><title><![CDATA[New comment by kaipereira in "How a devboard works (and how to make your own)"]]></title><description><![CDATA[
<p>Hey guys, thanks for all the love :D<p>The website went down because of the traffic and large images, so I've temporarily switched hosting, and it should stay up now (DNS propagation might take a bit though), but I'm going to get those images smaller ASAP, thanks to everyone who posted web archives!<p>I'm also going to alter some of the reasoning for some of the stuff like decoupling capacitors, but the guide is still meant for complete beginners, and lots of the terminology/reasoning can be pretty overwhelming, and I still have a lot to learn about decoupling/other stuff!<p>I'll also add a part about what you actually need on your devboard, that's a great suggestion!<p>You can find a JOURNAL.md in EVERY SINGLE one of my hardware projects <a href="https://github.com/KaiPereira?tab=repositories" rel="nofollow">https://github.com/KaiPereira?tab=repositories</a> so if you guys want to see more guides/tutorials, let me know :D</p>
]]></description><pubDate>Sat, 08 Nov 2025 20:31:31 +0000</pubDate><link>https://news.ycombinator.com/item?id=45859710</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=45859710</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=45859710</guid></item><item><title><![CDATA[How a devboard works (and how to make your own)]]></title><description><![CDATA[
<p>Article URL: <a href="https://kaipereira.com/journal/build-a-devboard">https://kaipereira.com/journal/build-a-devboard</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=45852029">https://news.ycombinator.com/item?id=45852029</a></p>
<p>Points: 96</p>
<p># Comments: 34</p>
]]></description><pubDate>Fri, 07 Nov 2025 22:35:28 +0000</pubDate><link>https://kaipereira.com/journal/build-a-devboard</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=45852029</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=45852029</guid></item><item><title><![CDATA[I built a system to detect guns in schools and call 911]]></title><description><![CDATA[
<p>Article URL: <a href="https://github.com/KaiPereira/school-gun-detection">https://github.com/KaiPereira/school-gun-detection</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=39994230">https://news.ycombinator.com/item?id=39994230</a></p>
<p>Points: 8</p>
<p># Comments: 10</p>
]]></description><pubDate>Wed, 10 Apr 2024 18:41:47 +0000</pubDate><link>https://github.com/KaiPereira/school-gun-detection</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=39994230</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=39994230</guid></item><item><title><![CDATA[Show HN: I made a simple portfolio builder]]></title><description><![CDATA[
<p>Article URL: <a href="https://www.designr.ink/">https://www.designr.ink/</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=39568678">https://news.ycombinator.com/item?id=39568678</a></p>
<p>Points: 5</p>
<p># Comments: 0</p>
]]></description><pubDate>Sat, 02 Mar 2024 00:39:39 +0000</pubDate><link>https://www.designr.ink/</link><dc:creator>kaipereira</dc:creator><comments>https://news.ycombinator.com/item?id=39568678</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=39568678</guid></item></channel></rss>