Pavlok-S Protocol

Introduction

The Pavlok 2 and 3 (S series) are BLE wearables that deliver vibration, audible beeps, and electric zaps as aversive stimuli. Protocol applies to firmware 5.4.73+ (6.x.x included); older firmware uses a fixed 0xFA duration value instead of the calculated value.

Protocol Negotiation

To confirm the device is an S-series Pavlok, read the Model Number String and verify it contains "Pavlok-S":

services:
  - uuid: "0000180a-0000-1000-8000-00805f9b34fb"
    description: "Device Information"
    characteristics:
      - uuid: "00002a24-0000-1000-8000-00805f9b34fb"
        description: "Model Number String — must contain 'Pavlok-S'"

BLE Profile

services:
  - uuid: "156e1000-a300-4fea-897b-86f698d74461"
    characteristics:
      - uuid: "00001001-0000-1000-8000-00805f9b34fb"
        properties: [write]
        role: tx
        description: "Vibrate"
      - uuid: "00001002-0000-1000-8000-00805f9b34fb"
        properties: [write]
        role: tx
        description: "Beep"
      - uuid: "00001003-0000-1000-8000-00805f9b34fb"
        properties: [write]
        role: tx
        description: "Zap"
      - uuid: "00001004-0000-1000-8000-00805f9b34fb"
        properties: [write]
        role: tx
        description: "LED"

Commands

Vibration and Beep Packet

Written to the Vibrate (0x1001) or Beep (0x1002) characteristic:

RR 0c II TA TO

Field	Description
RR	Repeats: 0x80 + repeat count (e.g., 0x81 = 1 repeat)
0c	Constant, unknown purpose
II	Intensity: 0–100
TA	Time Active (duration on): calculated for firmware 5.4.73+, 0xFA for older firmware
TO	Time Off (duration off between repeats): calculated for firmware 5.4.73+, 0xFA for older firmware

Zap Packet

Written to the Zap (0x1003) characteristic:

RR II

Field	Description
RR	Repeats: 0x80 + repeat count (e.g., 0x81 = 1 repeat)
II	Intensity: ???

Time calculation

Calculation for time, for firmware versions 5.4.73 and later:

public static int timeCodeForPavlok2(long timeCode) {
  if (timeCode > 10000L) {
    return 62;
  } else if (timeCode >= 3000L) {
    return (int)((timeCode - 3000L) / 500L) | 48;
  } else if (timeCode >= 1000L) {
    return (int)((timeCode - 1000L) / 100L) | 32;
  } else {
    return timeCode >= 200L ? (int)((timeCode - 200L) / 50L) | 16 : (int)(timeCode / 10L) | 0;
  }
}

Default value fed in is 0x280L/640L, which results in 0x18/24 The app hard-codes this value, however, it can be freely varied and will work accordingly.

Sample messages

• Vibrate at 30% intensity 1 time for default duration: write 0x810c1e1818 to 00001001-0000-1000-8000-00805f9b34fb
• Zap at 50% intensity twice: write 0x8232 to 00001003-0000-1000-8000-00805f9b34fb

Notes

• The Pavlok 3 exposes additional characteristics beyond the four documented here (RTC alarm, battery, etc.) but only the stimuli characteristics are relevant for actuation.
• LED characteristic (0x1004) format is not documented in the issue.
• This is a general-purpose behavior-change wearable, not an adult device.

Sources

• GitHub Issue (stpihkal#137)