This is pretty awesome. Although disheartening that you ended up spending much more than just buying a Yoto player or Toniebox. But I'm sure the learning and accomplishment have been worth the expense.

This is brilliant. Great design and great work. I love that the cartridges actually hold the content and aren't just NFC tags.

For lazy parents like myself: check out a Yoto player. It's web-connected, has limited internal storage, and the cards are just NFC cards -- but it is easy.

This device reminds me of https://en.wikipedia.org/wiki/HitClips (also worth reading: https://hackaday.com/2022/01/10/hitclips-custom-cartridge-ha... )

It's unfortunate that "always offline" needs to be added, as that would be the norm 15-20 years ago when portable media players were at the peak of their popularity. You can still buy SD/TF/microSD players at a very, very low price today.

For people who are thinking about getting into electronics: that project is very complex for what it does. Nothing wrong with it as long as your goal is to learn advanced fabrication techniques, but most people don't need any of this stuff for one-off, home projects with no strict low price / small size requirements.

The main culprit is that "custom ESP32-S3 board" - in this application, it is equivalent to a combination of a random off-the-shelf ESP32 board and a separate battery charger/protector. Half of the equipment on the list (hot air, hot plate, microscope, logic analyzer, etc...) is only needed for this board.

Weirdly enough, the rest of the device is a solid design, suitable for someone with "a few months" of electronic experience: lots of pre-made modules, and designing a carrier PCB for them. This means large and easy to solder 2.54mm hole spacing, regular soldering iron, no microscope, etc.. It's a really weird contrast for me....