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Youou Wand Vibrator Protocol

Introduction​

The Youou Wand Vibrator uses a 17-byte command packet with a monotonically increasing packet ID and an XOR checksum over the first 8 bytes.

BLE Profile​

ble_names:
  - "???"
services:
  - uuid: "???"
    characteristics:
      - uuid: "???"
        properties: [write]
        role: tx
        description: "Command endpoint"

Commands​

Vibration​

Packet structure (17 bytes):

aa 55 ID 02 03 01 VV ST CRC ff 00 00 00 00 00 00 00

Where:

  • ID = packet ID, monotonically increasing 0x00–0xff, wraps to 0x00
  • VV = speed value 0x00–0xf7 (247 decimal). Values above 0xf7 select patterns instead of speed.
  • ST = state: 0x01 if speed > 0, 0x00 if stopped
  • CRC = XOR of bytes 0–7 (bytes aa 55 ID 02 03 01 VV ST)

Maximum effective speed value: 0xf7 (247). Values 0xf8–0xff trigger built-in patterns.

Example — speed at 50%​

Assuming ID = 0x01 and speed = 124 (0x7c):

aa 55 01 02 03 01 7c 01 [XOR] ff 00 00 00 00 00 00 00

Notes​

  • BLE advertisement name and service/characteristic UUIDs are not documented in the source issue. The implementation was derived from TypeScript source code in buttplug-js.
  • The packet ID must be tracked in software and wraps at 255.

Sources​