# Hardware Notes

Yoto device specifications relevant to card making: cover image dimensions, LED display format, audio pipeline, device types, and label printing templates.

## Cover images

Yoto displays card cover images on the device. Required specifications:

- **Format:** JPEG or PNG
- **Dimensions:** 1500×1500 px (square)
- **File size:** Under 2 MB recommended
- **Colour space:** sRGB

YotoShelf generates cover images at 1500×1500 and converts to JPEG before upload.

## LED display (Mini)

The Yoto Mini has a 16×8 pixel LED matrix display. Per-track chapter icons are displayed here.

- **Format:** PNG
- **Dimensions:** 16×16 px (scaled to 16×8 on device)
- **Colour:** Single colour (monochrome); any colour is displayed as lit/unlit

YotoShelf's icon studio targets 16×16 icons. The Ideogram AI generator is configured for this constraint.

## Audio pipeline

Yoto expects AAC audio. YotoShelf transcodes any uploaded format to AAC via ffmpeg.

- **Format:** AAC (MPEG-4 audio)
- **Bitrate:** 64 kbps (matches Yoto's own conversion)
- **Sample rate:** 44.1 kHz
- **Channels:** Stereo (or mono for speech content)
- **Container:** M4A

Track duration is extracted from ffprobe output and stored alongside the track.

## Device types

| Device | Display | LED matrix | Notes |
|---|---|---|---|
| Yoto Player (3rd gen) | Cover art on screen | No | Large form factor |
| Yoto Mini | No screen | 16×8 LED | Portable |
| Yoto Player Mini (2024) | Cover art on screen | No | Compact |

## Label printing

YotoShelf generates printable card labels in PDF format. Labels are designed for:

- **Avery L7160** (21 labels per A4 sheet, 63.5×38.1 mm each)
- **Avery 5160** (30 labels per letter sheet, 2⅝×1 inch each)

Labels include the card cover image, title, and a QR code linking to the collection share page.