BlitzCityDIY Yoto Mini Hacking

Yoto Mini Hacking

by BlitzCityDIY
Last updated February 03, 2026
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ESP32 Pinouts

ESP32 Pin Connection
---LEFT SIDE--- ---
GND PROGRAM HEADER, 5
3V3 T67
EN PROGRAM HEADER, 2
SENSOR_VP / IO36 ENC2_A
SENSOR_VN / IO39 ENC1_A
IO34
IO35 ENC1_B
IO32 UARTRX / IRQIN CR95HF
IO33 UARTTX / IRQOUT CR95HF
IO25 SCL
IO26
IO27 ENC2_B
IO14
IO12
GND
IO13
NC
NC
NC
---RIGHT SIDE--- ---
GND GND
IO23 DISPLAY - TOP ROW, PIN 5 (?SPI)
IO22 DISPLAY - BOTTOM ROW, PIN 5 (?SPI)
TXD0 PROGRAM HEADER, 3
RXD0 PROGRAM HEADER, 4
IO21 SDA
NC
IO19 I2S_DIN
IO18 I2S_WS
IO5 I2S_BCLK
NC
NC
IO4
IO0 PROGRAM HEADER, 1
IO2
IO15
NC
NC
NC

Button Test Points

Switch Test Point
Power Button TP77 / Battery charger nQON
ENC1 Button T8
ENC2 Button T19

Encoder buttons are connected to the IO expander (P05: left, P04: right). Power button is connected to the battery charging IC

power button and encoder button test points

Peripherals

RFID Reader

CR95HF RFID Reader

CR95HF RFID Reader. Connected via UART. (SSI_0 and SSI_1 are tied to GND).

UART init:

Download File
Copy Code 
uart = busio.UART(
    board.D32,
    board.D33,
    baudrate=57600,
    bits=8,
    stop=2,
    timeout=0.1
)

Real Time Clock (RTC)

PCF8563 RTC

PCF8563 RTC module.

I2C Address: 0x51

eMMC Flash

eMMC Flash

I2S DAC

ES8156 I2S DAC

I2C address: 0x08

I2C configurable. Some links for software/use in other hardware:

Speaker Amplifier

AW88194

I2C address: 0x64

This was hard to figure out! I assumed this was a radio module based on search results from the chip markings and the fact that it was a castellated pads module. While tracing the speaker pads, the module had continuity with it and an aw881xx was mentioned in 3rd party licenses on the Yoto site and in the .ELF file dump from the default firmware. When you search for that though, nothing really comes up and the Awinic website is unreachable. Finally found it by searching for Awinic parts on LCSC. Chip markings match.

Have not been able to get it to work in CircuitPython. Did get an I2C readout from the factory firmware during boot to try and determine correct init sequence.

Battery Charger

SGM41513 Battery Charger

I2C Address: 0x1A

The factory firmware powers up the player by holding down the side button. That button is connected to the nQON pin on the SGM41513. When you press the button, hardware automatically enables BATFET, powering up the device.

IO Expander

TCAL6416 IO Expander?

I2C Address: 0x20

This I'm not 100% sure on because a search for the markings weren't bringing up anything ("6416 AM830"). Didn't see anything else that was an IO expander though, so added that and the TCAL6416 came up. Will hopefully be able to confirm after an I2C scan.

ESPTool Output

Copy Text 
esptool.py -p COM34 read_flash 0 ALL yoto_mini_v2.bin
Copy Text 
Detecting chip type... ESP32
Chip is ESP32-D0WD-V3 (revision v3.1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 78:1c:3c:e7:48:50
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Detected flash size: 8MB
8388608 (100 %)
8388608 (100 %)
Read 8388608 bytes at 0x00000000 in 786.3 seconds (85.3 kbit/s)...
Hard resetting via RTS pin...

CircuitPython

Copy Text 
Adafruit CircuitPython 10.1.0-beta.1-28-g6206c9d57c on 2026-01-12; Yoto Mini with ESP32
Board ID:yoto_mini
UID:87C1C37E8405
MAC:E0:04:FD:3F:D0:42

Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.
code.py output:
Hello World!

Code done running.

Enable Web Workflow via REPL

Copy Text 
with open('settings.toml', 'w') as f:
    f.write('CIRCUITPY_WIFI_SSID = "ssid_here"\n')
    f.write('CIRCUITPY_WIFI_PASSWORD = "ssid_password_here"\n')
    f.write('CIRCUITPY_WEB_API_PASSWORD = "passw0rd"\n')

print(open('settings.toml').read())

import microcontroller
microcontroller.reset()
web workflow connection

I2C Scan

Copy Text 
Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.
code.py output:
Checking board.I2C()...ADDED.
Checking board.STEMMA_I2C()...SKIPPED: 'module' object has no attribute 'STEMMA_I2C'
Checking busio.I2C(board.GP1, board.GP0)...SKIPPED: 'module' object has no attribute 'GP1'
----------------------------------------
I2C SCAN
----------------------------------------
board.I2C() addresses found: ['0x8', '0x18', '0x1a', '0x20', '0x51', '0x64']

Everything is accounted for except 0x18..

I2C Output During Boot

via Bus Pirate

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Research Links

This page (Yoto Mini Hacking) was last updated on February 03, 2026.

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Getting Started

Adafruit Playground is a wonderful and safe place to share your interests with Adafruit's vibrant community of makers and doers. Have a cool project you are working on? Have a bit of code that you think others will find useful? Want to show off your electronics workbench? You have come to the right place.

The goal of Adafruit Playground is to make it as simple as possible to share your work. On the Adafruit Playground users can create Notes. A note is a single-page space where you can document your topic using Adafruit's easy-to-use editor. Notes are like Guides on the Adafruit Learning System but guides are high-fidelity content curated and maintained by Adafuit. Notes are whatever you want them to be. Have fun and be kind.

Click here to learn more about Adafruit Playground and how to get started.