Yaydio 📻

No more scratched CDs!

Yaydio is a portable music player designed for kids, ditching the hassle of CDs in favor of easy-to-use keycards.

V1	Battery powered V2

✨ Features

• Keycard playback: Insert a keycard to instantly play an album.
• Simple controls: Play/pause, next/previous track, volume up/down.
• Audio options: Built-in speaker or connect headphones via the 3.5mm jack.
• Long battery life: Over 12 hours of play time.
• High capacity:
  • Up to 999 songs per album
  • Up to 9999 albums
  • Up to 65535 songs in total
  • Supports micro SD cards up to 32GB.
• MP3 compatibility: Plays all your favorite MP3 files.
• Affordable & accessible: Works with cost-effective MF S50 RFID keycards.

🕹️ Controls

Play / pause

• Inserting a keycard into the Yaydio will automatically start the playback.
• Press the left knob to pause or resume the playback.
• Remove the keycard to stop the playback.

Volume

• Turn the left knob to increase or decrease the volume.

Next / previous track

• Turn the right knob to skip to the next or previous track.

Random playback

• Press the right knob to toggle random mode on or off.
• When enabled, the Yaydio will pick the next track from the album at random.

Assign an album to a keycard

1. Insert the keycard into the Yaydio.
2. Press the left and right knobs simultaneously.
3. Turn the right knob to select the album number.
4. Press the right knob to write the album number to the keycard.

💿 Adding albums

Prepare the SD card

1. Format the SD card to FAT16 or FAT32 and name it YAYDIO.
2. Copy the README.md file onto the SD card.
3. Windows only: Download DriveSort and copy DriveSort.exe onto the SD card.
4. macOS only: Download FatDriveSorter and copy FatDriveSorter.app onto the SD card.

Copy albums to the SD card

1. Create a new folder named 0001, where "1" represents the next album number.
2. Copy the album's songs into the folder you created.
3. Rename the first song of the album to 001.mp3.
4. Repeat steps 1-3 for each album.

Sort the SD card

1. Windows only: Use DriveSort to sort the files alphabetically in the SD card's table.
   • Sort by long name and ascending.
   • Remember to press the save button.
   • You may need to sort every new folder individually and press save after each one.
2. macOS only: Use FatDriveSorter to sort the files alphabetically in the SD card's table.
   • Next to Order: select Directories first.
   • Tick the box next to Case-sensitive:.

🔨 Make your own

🧱 Parts

I've added an Amazon link for each part so you know what to look for. You'll probably find the parts much cheaper in other stores.

• 1 x Arduino Nano clone with USB-C port (pin headers not soldered on) (Amazon.de)
• 1 x PN532 NFC Module V3 (Amazon.de)
• 1 x DY-SV5W Voice Module (Amazon.de) Note: Some modules don't come with a 1K Ohm resistor on the RXD pin. If this is the case, you'll have to connect D13 and the RXD pin with a 1K Ohm resistor (see this).
• 1 x 4-digit 7-segment 0.36 inch display with TM1637 driver chip (Amazon.de)
• 2 x Rotary encoder with button and 15 mm D-shaft (not the KY-040 module!) (Amazon.de)
• 1 x Limit switch 12.8mm x 5.8mm (Amazon.de)
• 1 x Speaker 3W 8Ohms 70mm x 30mm x 15mm (Amazon.de)
• 1 x SM5308 battery charger module (Amazon.de)
• 1 x Battery 3.7V 3000mAh Li-ion 18650 (Amazon.de)
• A bunch of 13.56 MHz MF S50 ISO14443 (Mifare Classic) RFID keycards (Amazon.de) Note: If you plan on making multiple Yaydios sharing the same keycards, make sure you get keycards that aren't "magic". The cards must have a fixed UID that is not encrypted or reprogrammable.
• Optional: 1 x Double-sided PCB board 20 x 80mm with 168 holes (Amazon.de)
• A bunch of wires (Amazon.de)

🧵 Wiring

Left Rotary Encoder	Arduino Nano
SW	D2
SW GND	GND
DT	D3
CLK	D4
GND	GND

Right Rotary Encoder	Arduino Nano
SW	D5
SW GND	GND
DT	D6
CLK	D7
GND	GND

4-Digit 7-Segment 0.36 Inch TM1637	Arduino Nano
CLK	D10
DIO	D11
GND	GND
5V	5V

Card Switch
COM	Arduino GND
NO	Battery Module GND
NC	A3

SM5308 Battery Module
5V	Arduino 5V
GND	Card Switch NO
B+	Battery +
B-	Battery -

PN532 NFC Module V3	Arduino Nano
GND	GND
VCC	5V
SDA	A4
SCL	A5
RSTPDN	D9
Switches: ON, OFF (I2C mode)

DY-SV5W Voice Module
-	Arduino GND
+	Arduino 5V
TXD	Arduino D12
RXD	Arduino D13
Speaker +	Speaker +
Speaker -	Speaker -
Switches: OFF, OFF, ON (UART mode)

🏗️ Assembly

yaydio.step contains the models of the 3D-printed parts.

Printer: Bambu Lab A1 with AMS

Nozzle: 0.4mm

Preset: 0.20mm Standard @BBL A1 with supports enabled

Filaments:

• Bambu Lab PLA Matte Mandarin Orange (11300)
• Bambu Lab PLA Matte Marine Blue (11600)
• Bambu Lab PLA Matte Dark Blue (11602)
• or
• Bambu Lab PLA Matte Lemon Yellow (11400)
• Bambu Lab PLA Matte Sakura Pink (11201)
• Bambu Lab PLA Matte Lilac purple (11700)