Ultrahuman Protocol¶

This describes the Bluetooth attribute protocol used between the Ultrahuman Air smart ring (firmware version 02.00.07.46) and the Ultrahuman Android application (version 2.52.2.0, package com.ultrahuman.android).

Device Identification¶

The BLE device name matches the Regex pattern UH_[0-9A-F]{12}. For example "UH_FE16F0F1E2D3".

Device Information service¶

The standard BLE device information service 0000180a-0000-1000-8000-00805f9b34fb supports reading - Read Request (0x0a) / Read Response (0x0b):

Ultrahuman Device State service¶

The custom BLE service 86f61000-f706-58a0-95b2-1fb9261e4dc7 supports one characteristic 86f61001-f706-58a0-95b2-1fb9261e4dc7.

This characteristic can be read - Read Request (0x0a) / Read Response (0x0b). In addition Ultrahuman Command requests also trigger typically between 0 and 2 notifications of the characteristic - Handle Value Notification (0x1b)

payload structure¶

examples:

4c4c2900000317 = battery level 79% (0x4c), device state "charging" (0x03), device temperature 23°C (0x17)

00000000000000 = unknown device state - sometimes received in response to read requests

Ultrahuman Command Response service¶

This custom BLE service 86f65000-f706-58a0-95b2-1fb9261e4dc7 allows writing commands 86f65001-f706-58a0-95b2-1fb9261e4dc7 and receiving their responses via value notifications 86f65002-f706-58a0-95b2-1fb9261e4dc7.

The first byte of both the Write Command (0x52) and the Handle Value Notification (0x1b) payload encodes the Ultrahuman opcode.

0x02 Set Time Command¶

Sets the current time.

example:

020001a5c4ac67966c = opcode 0x02, time 2025-02-12 15:56:21 (0x67acc4a5)

0x02 Set Time Response¶

Response echos back the effective time.

example:

020001a5c4ac67966c = opcode 0x02, success (0x00), OK (0x01), time 2025-02-12 16:56:56 (0x67acc45c)

0x04 Get Recordings Command¶

Requests historical sensor recordings.

Normally a new entry is recorded every ca 5 minutes. In Workout mode a new entry is recorded every ca 2 seconds.

examples:

040100 = opcode 0x04; request recording 1 (0x0001) and newer

042f0f = opcode 0x04; request recording 3887 (0x0f2f) and newer

0x04 Get Recordings Response¶

One or more responses are received for each command. The response contains 0 or more, at least up to 7, records.

examples:

04ee00ffff = opcode 0x04; 0 recordings

040001451da3670000000a451da3670000000000000000451da3670000000000006a00d0ae = opcode 0x04, 1 recordings, empty record 106 (0x006a)

0400028a99a5670000000a8a99a56700000000000000008a99a5670000000000007206ae9aa56700000064ae9aa5670000000000000000ae9aa5670000000000007306adad = opcode 0x04, 2 recordings, empty record 1650 (0x0672), empty record 1651 (0x0673)

040001ac23a56747520005ac23a56734340b42fec50942ac23a5670000000052003205759a = opcode 0x04, 1 recordings, record 1330 (0x0532) with sensor readings

recording structure¶

The recording consists of 3 sensor groups (A, B and C), each starting with its own timestamp. Depending on operation mode the timestamps are identical or different.

example:

E945AD67443362018546AD67785B0E4230D20C428546AD67960025003300 = time A 2025-02-13 01:07:53 (0x67AD45E9), heart reate 68 BPM (0x44), heart rate variability 51 (0x33), SpO2 98% (0x62), time B 2025-02-13 01:10:29 (0x67AD8546), max skin temperatur 35.58°C (0x420E5B78), min skin temperature 35.21°C (0x420CD230), time C 2025-02-13 01:10:29 (0x67AD4685), activity level 150 (0x0096), steps 37 (0x0025), stress 51 (0x0033)

0x05 Get Time Command¶

Retrieve the current device time.

example:

05 = opcode 0x05

0x05 Get Time Response¶

The current UTC time of the device.

example:

050001d8d2ac67a6e6 = opcode 0x05, success (0x00), OK (0x01), time 2025-02-12 16:56:56 (0x67acd2d8)

0x07 Get Earliest Recording Index Command¶

Request the index of the oldest recording retrivable via 0x04 Get Recordings.

example:

07 = opcode 0x07

0x07 Get Earliest Recording Index Response¶

example:

070001c401bed7 = opcode 0x07, success (0x00), OK (0x01), first recording 452 (0x001c4)

0x08 Get Latest Recording Index Command¶

Request the index of the newest record retriveable via 0x04 Get Recordings.

example:

08 = opcode 0x08

0x08 Get Latest Recording Index Response¶

example:

0800017306c320 = opcode 0x08, success (0x00), OK (0x01), latest recording 1651 (0x0673)

0x70 Activate Airplane Mode Command¶

Airplane Mode disables the BLE radio on the ring. The radio can be re-enabled by charging the ring.

example:

70 = opcode 0x70

0x70 Activate Airplane Mode Response¶

The ring will switch of it's radio immediately after sending a success response.

example:

70000161779d = opcode 0x70, success (0x00), OK (0x01)

70ff02ff00ff = opcode 0x70, failure (0xFF), ring is charging (0x02)

0x98 Reset Device Command¶

Purges recorded data from the device and reboots immediately without generating a response.

example:

98 = opcode 0x98

0xD1 Disable Power Saving Mode Command¶

Enables the SpO2 sensing.

example:

D1 = opcode 0xD1

0xD1 Disable Power Saving Mode Response¶

If successful, the next recordings are going to try to sense SpO2.

example:

d10001d1ac3a = opcode 0xD1, success (0x00), OK (0x01)

0xD2 Enable Power Saving Mode Command¶

Disable SpO2 sensing.

example:

D2 = opcode 0xD2

0xD2 Enable Power Saving Mode Response¶

If successful, the next recordings are NOT going to try to sense SPO2.

example:

d2000100f0e1 = opcode 0xD2, success (0x00), OK (0x01)