The Yoto Mini and Yoto Player toys are fun, screenless audio players aimed at kids. The devices use NFC cards to playback stories or music for kids to listen to without being attached to a phone or tablet. But what interested us the most about them was what was inside: an ESP32 processor, which means that it could in theory run CircuitPython.

In this guide, you'll see how to take your Yoto Mini apart and load and run CircuitPython firmware onto it with access to almost all of the peripherals onboard. As of writing, the speaker init sequence hasn't been fully cracked, but there is headphone output and every other peripheral is accessible, including the eMMC flash for chonky storage. There's also a page detailing the reverse engineering process, from using multimeters to looking at the shipped firmware with Ghidra.

Why Hack the Yoto Players?

It seems that every other day you hear about an IoT device no longer being supported or servers shutting down, essentially bricking your devices. Although this fate is not currently affecting the Yoto Players, you could say that about any IoT device on the market right now. This guide serves as an example of how you can approach a device, reverse engineer it and get firmware like CircuitPython running on it to save it from an e-waste future and to truly own your device.

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