--- title: Show HN: Marelleo, an open-source story box I built for... description: A father with no electronics background built an RFID story box for his three kids, inspired by the Toniebox but without its closed content catalogue. He... canonical: https://daily.dev/posts/show-hn-marelleo-an-open-source-story-box-i-built-for-my-kids-using-esp32-u9gnhvm4s twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Show HN: Marelleo, an open-source story box I built for my kids using ESP32 | daily.dev og:description: A father with no electronics background built an RFID story box for his three kids, inspired by the Toniebox but without its closed content catalogue. He... og:url: https://daily.dev/posts/show-hn-marelleo-an-open-source-story-box-i-built-for-my-kids-using-esp32-u9gnhvm4s og:image: https://api.daily.dev/og/posts/u9Gnhvm4s.png og:image:alt: Show HN: Marelleo, an open-source story box I built for my kids using ESP32 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Show HN: Marelleo, an open-source story box I built for my kids using ESP32 **[Hacker News](https://daily.dev/sources/hn)** · 24 min read · 0 upvotes · 0 comments ## Summary A father with no electronics background built an RFID story box for his three kids, inspired by the Toniebox but without its closed content catalogue. He started on a breadboard with an ESP32, moved to perfboard after wiring failures, then designed a custom PCB with 491 hand-routed tracks in KiCad. A misconfigured regulator would have sent 13.7V into a 3.3V rail, and a reversed diode and a zero-clearance design rule check were caught before ordering. Five assembled boards cost 160 euros from JLCPCB and worked on first power-up after fixing a swapped NFC ribbon connection. The firmware supports custom MP3s, internet radio streams, and self-updating over WiFi with a rollback safety net. Everything, including enclosure files, PCB files, firmware and documentation, is published under MIT license at github.com/Zebra-Rodeo/marelleo. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What microcontroller is good for building a DIY RFID audio player for kids like a Toniebox alternative? An ESP32 development board works well for this, since it has built-in WiFi, enough power to decode MP3 audio, and can be programmed like an Arduino, all for a few euros. It avoids the overkill of a Raspberry Pi (too big, slow 20-second boot) and the steep learning curve of low-level chips requiring C and lengthy datasheets. _Makers comparing microcontrollers for audio or IoT projects can track real build experiences on daily.dev._ ### What mistakes should I check for before ordering a custom PCB from a manufacturer like JLCPCB? Three critical errors are worth double-checking: using a fixed-output regulator chip with a voltage divider meant for an adjustable one (which can send dangerously high voltage like 13.7V into a 3.3V rail), reversed diode polarity that prevents the board from starting at all, and a design rule checker misconfigured with zero clearance that silently approves bad layouts. Catching these before ordering matters because the minimum order is typically five boards, so one mistake ruins the whole batch. _Anyone about to send a PCB order for fabrication can learn from real failure cases shared on daily.dev._ ### How can a battery-powered embedded device safely update its own firmware over WiFi without risking getting bricked? Download the new firmware into a second, inactive memory partition, verify its file fingerprint, and only switch over if the check passes, so a power cut mid-transfer leaves the device running its old, working version. Add a trial period requiring the new version to successfully connect to the network across three startups; if it fails all three, the device automatically rolls back to the previous version before even activating other features. _Developers building safe OTA update logic for IoT devices can find real-world implementation lessons on daily.dev._ ## Community take How the wider developer community reacted, aggregated from 2 discussions and 41 comments across hackernews, lobsters (as of 2026-10-31). **TL;DR:** The project itself is widely praised as an impressive, well-documented DIY alternative to closed story-box products, but a lot of the discussion gets derailed by complaints that the writeup reads as LLM-generated, which several people say kept them from finishing it. **Sentiment:** 55% positive · 20% mixed · 25% skeptical **The case for** - Many found the step-by-step account of learning electronics from scratch, including mistakes and fixes, genuinely inspiring and educational. - Open-sourcing firmware, PCB files, and enclosure design under MIT was well received as a welcome alternative to closed subscription-based story boxes. - Several commenters said they have similar projects in mind or in progress and appreciated the practical details on PCB design and NFC triggering. **The pushback** - Many commenters said the article's prose has a strong LLM/AI-generated feel (e.g. repetitive rhetorical patterns) that made it hard or impossible to finish reading. - Some pushed back that criticizing AI-assisted writing is gatekeeping when the underlying project and effort are real. - One commenter said they wouldn't want this kind of passive audio toy in their home at all, preferring more active, kid-created content like cassette recordings. **By community** - hackernews (mixed): Praise for the engineering and open-source approach runs alongside a running debate about whether the writeup's AI-sounding prose is a dealbreaker or beside the point. - lobsters (skeptical): Comments mostly focus on how the LLM-flavored writing style made the article hard to finish, with one dissenting voice questioning the toy concept itself. **Hottest debate:** Whether the article's apparent LLM-assisted writing style is a legitimate complaint or unfair gatekeeping against a parent who clearly did real, documented hardware work. **Open questions** - How does content get curated/added for each child individually? - How easy would it be to adapt the device to use standard AA batteries instead of the current power setup? - How long does the battery last on a charge? **Highlights** > There are some ugly tell tale signs of AI writing here: No screen, no menu, no parent [...] You’re not buying a player, you’re buying a subscription [...] I particularly hate the first one, don't AI sloppers notice how horrible it is to read "No x, no y, no z"? > — [Muhammad523 on hackernews](https://news.ycombinator.com/item?id=50314290) > Why the gatekeeping? It’s their choice how they spend their time and tokens, and nobody is forced to use it. As long as they had fun and enjoyed the process, that’s what counts. Enterprise software deployment is a different story, of course. > — [robotswantdata on hackernews](https://news.ycombinator.com/item?id=50314760) > I agree with the commenters who were jarred by the heavy use of LLMisms -- the writing was genuinely painful to read. What a really fun project though! Props for seeing it through a debugging phase, it can really be worrying when you get your boards and they just don't work. > — [corroclaro on hackernews](https://news.ycombinator.com/item?id=50315805) > I only skimmed the article because just _reading_ about the effort involved in building custom electronics wears me out. This is an incredible amount of work to build something I wouldn't want in a house full of kids, but I completely understand the disdain for things like Tonies and anything that sets out to trap children and their families into subscription services. Personally, I don't like things that make noise with so little effort. When I was five I had more than one cassette player and I recorded my own stories on a microcassette. I understood where the content was coming from and that I could record my own. It was less passive than these kinds of toys. I listened mostly with headphones. > — [gnafuthegreat on lobsters · 1 points](https://lobste.rs/s/hgx46o/marelleo_story_box_i_built_for_my_kids#c_cqqg8q) > Nice work. Although I'd probably had used one of the newer esp32 from seeed Studio with integrated battery pads (unfortunately the BatteryPal from PNLabs is still in the making). A DFPlayer Mini might also habe saved some time... There also is a german project called Tonuino, which is quite similar and has lots of examples and documentation - they even designed a custom PCB which unfortunately is no longer available: https://github.com/tonuino/TonUINO-TNG Another rasperry focussed project that has a web interface is Phoniebox: https://phoniebox.de/index-en.html There also is a toniebox hack, which lets you setup a self-hosted content server: https://gt-blog.de/toniebox-hacking-how-to-get-started/ > — [sandreas on hackernews · 2 comments](https://news.ycombinator.com/item?id=50314682) **Source threads** - [hackernews](https://news.ycombinator.com/item?id=50260753) · 128 points · 37 comments - [lobsters](https://lobste.rs/s/hgx46o/marelleo_story_box_i_built_for_my_kids) · 3 points · 4 comments ## Similar posts on daily.dev - [Child-Friendly Music Player Uses RFID](https://daily.dev/posts/child-friendly-music-player-uses-rfid-ps1yeueaq) · Hackaday · 0 upvotes · 0 comments - [Someone turned an ESP32 T-LoRa Pager into a portable music machine, and you can too](https://daily.dev/posts/someone-turned-an-esp32-t-lora-pager-into-a-portable-music-machine-and-you-can-too-61bemapnw) · XDA Developers · 0 upvotes · 0 comments - [An ESP32-S3 e-paper development board with 3.97-inch touchscreen, LoRa, and NFC](https://daily.dev/posts/an-esp32-s3-e-paper-development-board-with-3-97-inch-touchscreen-lora-and-nfc-j6zceqyxi) · CNX Software · 0 upvotes · 0 comments - [Birduino: A card-triggered audio player for \[learning\] the birds](https://daily.dev/posts/birduino-a-card-triggered-audio-player-for-learning-the-birds-gwiczby5d) · Hacker News · 0 upvotes · 0 comments --- Tags: [#hardware](https://daily.dev/tags/hardware), [#iot](https://daily.dev/tags/iot) [View this post on daily.dev](https://daily.dev/posts/show-hn-marelleo-an-open-source-story-box-i-built-for-my-kids-using-esp32-u9gnhvm4s) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Show HN: Marelleo, an open-source story box I built for my kids using ESP32","url":"https://daily.dev/posts/show-hn-marelleo-an-open-source-story-box-i-built-for-my-kids-using-esp32-u9gnhvm4s","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/show-hn-marelleo-an-open-source-story-box-i-built-for-my-kids-using-esp32-u9gnhvm4s"},"datePublished":"2026-10-31T11:39:28.060Z","dateModified":"2026-10-31T15:25:22.621Z","description":"A father with no electronics background built an RFID story box for his three kids, inspired by the Toniebox but without its closed content catalogue. 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