What is this?

Phonytony is a RFID mp3 player for my daughter. It is similar to the popular Toniebox and to the various open Phoniebox variants.

The hardware is built around an ESP32 with a MAX98357 I2S DAC/AMP module from Adafruit, a RC522 RFID reader and a MCP23S17 SPI GPIO expander. The software uses libmad for mp3 decoding.

How does it work? You hold a RFID card close to the reader. The box reads the tag, looks it up in a JSON file and then plays an audio play from the SD card.

box closed
The closed box.
box open
Opening the lid to reveal the guts.
A closeup on the board.