Your project is super cool and really well executed. Thanks for sharing. I’ve had success with cheap blank NFC cards instead of the official MyYo York cards. I have a quick breakdown in my recent comment history if you’re curious.
This is not my experience. I purchased blank NFC cards and made myself this guide to get them working just fine:
1. Use NXP TagWriter to format card to NDEF format.
2. Use Smart NFC tools app to copy from existing MyYo card to new one.
3. Using the Yoto app, Play the playlist on the target Yoto. This will trigger the tracks to download onto the YoTo.
4. Make sure all tracks are downloaded onto Yoto before inserting new card.
After a few years now with two kids using Yoto, however, I think it is a little overkill to go this route and the reduced friction of using Yoto’s own cards makes it worth it, despite the cost. But this may help others who use them differently than we do!