Sanitas SBF70 measured data are completely different from the displayed date on the scale

[flow778]

Description

Hi,

I was able to connect the scale and I receive a bunch of data via the mqtt connection in Home Assistant.
My problem is, that the data shown on the display of the scale do not correspond to the data shown in the logs or in Home Assistant. Further the data in the log do not change, even if change the weight on the scale.
The real weight shown on the scale gives me 106,1 kg and on the log I get 12,80 kg.

Steps to Reproduce

Here is my yaml:
version: 1
scale:
weight_unit: kg
height_unit: cm
unknown_user: nearest
ble:
handler: auto
scale_mac: 50:8C:B1:5D:EF:2C
users:

• name: xxx
  slug: xxxx
  height: 180
  birth_date: 1992-06-23
  gender: male
  is_athlete: false
  weight_range:
  min: 103
  max: 107
  last_known_weight: 105
  global_exporters:
• type: mqtt
  broker_url: mqtt://192.168.1.10:1883 
  topic: scale/body-composition
  qos: 0
  retain: true
  username: mqtt
  password: XXXXXXXXX
  client_id: ble-scale-sync
  ha_discovery: true
  ha_device_name: SBF70 Waage
  runtime:
  continuous_mode: true
  scan_cooldown: 30
  dry_run: false
  debug: false

Scale Brand / Model

Sanitas SBF70

Platform

Linux (Raspberry Pi)

Node.js Version

v20.19.2

App Version

1.7.5

Debug Logs

These are the measurements in the log:
2026-04-17 12:38:45.957 [Sync] Measurement received: 12.80 kg / 0 Ohm
2026-04-17 12:38:45.958 [Sync] Body composition:
2026-04-17 12:38:45.959 [Sync]   bmi: 3.95
2026-04-17 12:38:45.960 [Sync]   bodyFatPercent: 3
2026-04-17 12:38:45.960 [Sync]   waterPercent: 70.81
2026-04-17 12:38:45.961 [Sync]   boneMass: 0.52 kg
2026-04-17 12:38:45.962 [Sync]   muscleMass: 6.70 kg
2026-04-17 12:38:45.962 [Sync]   visceralFat: 1
2026-04-17 12:38:45.963 [Sync]   physiqueRating: 9
2026-04-17 12:38:45.964 [Sync]   bmr: 1043
2026-04-17 12:38:45.964 [Sync]   metabolicAge: 49
2026-04-17 12:38:45.965 [Sync] Exporting to: mqtt...
2026-04-17 12:38:46.042 [MQTT] Published HA discovery for 11 metrics (user: xxxxx).
2026-04-17 12:38:46.044 [MQTT] Published to scale/body-composition/xxxxxx (qos=0, retain=true).
2026-04-17 12:38:46.051 [Sync] Done.

[KristianP26]

Hi @flow778, thanks for the report. I had a look — your scale shows 106.1 kg but the log reads 12.80 kg, which means byte [4] in the notification arrived as 0x01. That does not match what our adapter expects for a stable weight frame, so the adapter is picking the wrong frame or the wrong offset.

To nail it down I need the raw bytes from one or two live weigh-ins. I pushed a debug build that logs every raw frame the scale sends, before any parsing happens. It will show up in the log as:

[BLE] BeurerSanitas frame (len=N, cmd=0xNN): [AA BB CC ...]

How to run it

The image ghcr.io/kristianp26/ble-scale-sync:issue-112 should be ready in ~10 minutes. Two small changes to your current Docker setup:

1. Pull the debug image
2. Add DEBUG=true as an env var
3. (Optional but helpful) set continuous_mode: false so it exits after one reading and the log is short

docker pull ghcr.io/kristianp26/ble-scale-sync:issue-112

docker run --rm -it --network host --cap-add NET_ADMIN --cap-add NET_RAW \
  --group-add 112 -v /var/run/dbus:/var/run/dbus:ro \
  -v $PWD/config.yaml:/app/config.yaml:ro \
  -e DEBUG=true \
  ghcr.io/kristianp26/ble-scale-sync:issue-112

Then step on the scale, wait for it to settle, step off. Paste everything from BLE lines here and I will map out the correct byte offsets for SBF70 and ship a fix.

Two extra things that will help when you reply:

• Is the scale set to display kg or lb physically? (The SBF70 can switch units on the hardware.)
• What name does the scale advertise? You can see it in the log on the Matched: line, or in scan output (docker run ... scan).

Thanks for the patience — SBF70 is known to have slightly different frame formats depending on firmware, and the raw bytes are the only way to know which variant you have.

[flow778]

Hi @KristianP26 ,

thanks much for the fast response. :-)
The scale displays kg

I installed the image and used my previous config.yaml. Please find the full output below.

sasel@testpi:~/ble-scale-sync-debug $ docker run --rm -it --network host --cap-add NET_ADMIN --cap-add NET_RAW
--group-add 112
-v /var/run/dbus:/var/run/dbus:ro
-v $PWD/config.yaml:/app/config.yaml:ro
-e DEBUG=true
ghcr.io/kristianp26/ble-scale-sync:issue-112
Resetting Bluetooth adapter...
Set Powered for hci0 failed with status 0x14 (Permission Denied)
Set Powered for hci0 failed with status 0x14 (Permission Denied)
Bluetooth adapter reset OK
2026-04-18 14:44:31.466 [Config] Loading config from config.yaml

2026-04-18 14:44:31.702 [Sync] BLE Scale Sync
2026-04-18 14:44:31.703 [Sync] Scanning for scale 50:8C:B1:5D:EF:2C...
2026-04-18 14:44:31.706 [Sync] Adapters: Senssun Fat Scale, QN Scale, Renpho ES-WBE28, Renpho ES-26BB, Xiaomi Mi Scale 2, Yunmai, Beurer / Sanitas, Sanitas SBF72/73, Soehnle Shape/Style, Medisana BS44x, Trisa, ES-CS20M, Exingtech Y1, Excelvan CF369, Hesley, Inlife, Digoo, 1byone (Eufy), 1byone Scale (new), Active Era BS-06, MGB (Swan/Icomon/YG), Hoffen BS-8107, Standard GATT (BCS/WSS)

2026-04-18 14:44:31.710 [Sync] Running exporter healthchecks...
2026-04-18 14:44:32.929 [Sync] mqtt: OK
2026-04-18 14:44:32.940 [BLE:debug] BLE handler: node-ble (BlueZ D-Bus)
2026-04-18 14:44:33.409 [BLE:debug] Discovery started
2026-04-18 14:44:33.416 [BLE] Scanning for device...
2026-04-18 14:44:36.497 [BLE:debug] Found device: SANITAS SBF70 [50:8C:B1:5D:EF:2C]
2026-04-18 14:44:36.500 [BLE:debug] Stopping discovery before connect...
2026-04-18 14:44:36.522 [BLE:debug] Discovery stopped
2026-04-18 14:44:37.026 [BLE:debug] Connect attempt 1/6...
2026-04-18 14:44:51.227 [BLE:debug] Connected (took 14201ms)
2026-04-18 14:44:51.228 [BLE] Connected. Discovering services...
2026-04-18 14:44:54.283 [BLE:debug] Services: [00001800-0000-1000-8000-00805f9b34fb, 00001801-0000-1000-8000-00805f9b34fb, 0000180a-0000-1000-8000-00805f9b34fb, 0000ffe0-0000-1000-8000-00805f9b34fb, f000ffc0-0451-4000-b000-000000000000]
2026-04-18 14:44:54.288 [BLE] Matched adapter: Beurer / Sanitas
2026-04-18 14:44:54.768 [BLE:debug] Service 00001800-0000-1000-8000-00805f9b34fb: chars=[00002a00-0000-1000-8000-00805f9b34fb, 00002a01-0000-1000-8000-00805f9b34fb, 00002a02-0000-1000-8000-00805f9b34fb, 00002a03-0000-1000-8000-00805f9b34fb, 00002a04-0000-1000-8000-00805f9b34fb]
2026-04-18 14:44:54.775 [BLE:debug] Char 00002a00-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.782 [BLE:debug] Char 00002a01-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.788 [BLE:debug] Char 00002a02-0000-1000-8000-00805f9b34fb: flags=[read, write]
2026-04-18 14:44:54.793 [BLE:debug] Char 00002a03-0000-1000-8000-00805f9b34fb: flags=[write]
2026-04-18 14:44:54.798 [BLE:debug] Char 00002a04-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.799 [BLE:debug] Service 00001801-0000-1000-8000-00805f9b34fb: chars=[00002a05-0000-1000-8000-00805f9b34fb]
2026-04-18 14:44:54.804 [BLE:debug] Char 00002a05-0000-1000-8000-00805f9b34fb: flags=[indicate]
2026-04-18 14:44:54.805 [BLE:debug] Service 0000180a-0000-1000-8000-00805f9b34fb: chars=[00002a23-0000-1000-8000-00805f9b34fb, 00002a24-0000-1000-8000-00805f9b34fb, 00002a25-0000-1000-8000-00805f9b34fb, 00002a26-0000-1000-8000-00805f9b34fb, 00002a27-0000-1000-8000-00805f9b34fb, 00002a28-0000-1000-8000-00805f9b34fb, 00002a29-0000-1000-8000-00805f9b34fb, 00002a2a-0000-1000-8000-00805f9b34fb, 00002a50-0000-1000-8000-00805f9b34fb]
2026-04-18 14:44:54.809 [BLE:debug] Char 00002a23-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.814 [BLE:debug] Char 00002a24-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.819 [BLE:debug] Char 00002a25-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.823 [BLE:debug] Char 00002a26-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.828 [BLE:debug] Char 00002a27-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.833 [BLE:debug] Char 00002a28-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.838 [BLE:debug] Char 00002a29-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.843 [BLE:debug] Char 00002a2a-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.848 [BLE:debug] Char 00002a50-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.849 [BLE:debug] Service 0000ffe0-0000-1000-8000-00805f9b34fb: chars=[0000ffe4-0000-1000-8000-00805f9b34fb, 0000ffe2-0000-1000-8000-00805f9b34fb, 0000ffe3-0000-1000-8000-00805f9b34fb, 0000ffe1-0000-1000-8000-00805f9b34fb, 0000ffe5-0000-1000-8000-00805f9b34fb]
2026-04-18 14:44:54.853 [BLE:debug] Char 0000ffe4-0000-1000-8000-00805f9b34fb: flags=[read, write]
2026-04-18 14:44:54.858 [BLE:debug] Char 0000ffe2-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.862 [BLE:debug] Char 0000ffe3-0000-1000-8000-00805f9b34fb: flags=[write]
2026-04-18 14:44:54.867 [BLE:debug] Char 0000ffe1-0000-1000-8000-00805f9b34fb: flags=[write, notify]
2026-04-18 14:44:54.871 [BLE:debug] Char 0000ffe5-0000-1000-8000-00805f9b34fb: flags=[read]
2026-04-18 14:44:54.872 [BLE:debug] Service f000ffc0-0451-4000-b000-000000000000: chars=[f000ffc1-0451-4000-b000-000000000000, f000ffc2-0451-4000-b000-000000000000]
2026-04-18 14:44:54.877 [BLE:debug] Char f000ffc1-0451-4000-b000-000000000000: flags=[write-without-response, write, notify]
2026-04-18 14:44:54.882 [BLE:debug] Char f000ffc2-0451-4000-b000-000000000000: flags=[write-without-response, write, notify]
2026-04-18 14:44:54.886 [BLE:debug] Looking for notify=0000ffe100001000800000805f9b34fb, write=0000ffe100001000800000805f9b34fb
2026-04-18 14:44:54.898 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:44:55.469 [BLE] Subscribed to notifications. Step on the scale.
2026-04-18 14:44:59.902 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:45:04.903 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:45:06.345 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 01 2B]
2026-04-18 14:45:06.993 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 6C]
2026-04-18 14:45:07.943 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5F]
2026-04-18 14:45:08.843 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 60]
2026-04-18 14:45:09.793 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5E]
2026-04-18 14:45:09.903 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:45:10.693 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5F]
2026-04-18 14:45:11.643 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5F]
2026-04-18 14:45:12.543 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5E]
2026-04-18 14:45:13.493 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 01 08 5E]
2026-04-18 14:45:14.693 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 00 08 5E]
2026-04-18 14:45:14.904 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:45:15.593 [BLE:debug] BeurerSanitas frame (len=5, cmd=0x58): [E7 58 00 08 5E]
2026-04-18 14:45:19.906 [BLE:debug] Unlock write: [e7 01]
2026-04-18 14:45:20.693 [BLE:debug] BeurerSanitas frame (len=13, cmd=0x59): [E7 59 03 01 01 00 00 00 00 00 00 00 65]
2026-04-18 14:45:20.699 [BLE] Reading complete: 12.80 kg / 0 Ohm

2026-04-18 14:45:23.402 [Sync] Measurement received: 12.80 kg / 0 Ohm
2026-04-18 14:45:23.403 [Sync] Body composition:
2026-04-18 14:45:23.404 [Sync] bmi: 3.95
2026-04-18 14:45:23.405 [Sync] bodyFatPercent: 3
2026-04-18 14:45:23.406 [Sync] waterPercent: 70.81
2026-04-18 14:45:23.406 [Sync] boneMass: 0.52 kg
2026-04-18 14:45:23.407 [Sync] muscleMass: 6.70 kg
2026-04-18 14:45:23.408 [Sync] visceralFat: 1
2026-04-18 14:45:23.409 [Sync] physiqueRating: 9
2026-04-18 14:45:23.409 [Sync] bmr: 1043
2026-04-18 14:45:23.410 [Sync] metabolicAge: 49
2026-04-18 14:45:24.147 [Sync] Exporting to: mqtt...
2026-04-18 14:45:24.412 [MQTT] Published HA discovery for 11 metrics (user: florian).
2026-04-18 14:45:24.414 [MQTT] Published to scale/body-composition/florian (qos=0, retain=true).
2026-04-18 14:45:24.420 [Sync] Done.

[KristianP26]

@flow778 raw frames cracked it. Thanks for capturing them.

Root cause

The SBF70 sends weight in a compact 5-byte 0x58 frame with the byte layout:

[E7 58 flag weight_hi weight_lo]
       |   |_________|
       on-scale     BE uint16 * 50/1000 = kg

The adapter expected the longer BF700/BF800 frame format (weight at bytes [4-5], minimum 6 bytes) so it rejected every live weight frame and then mis-parsed the 0x59 finalize frame, yielding the stuck 12.80 kg you were seeing.

The 0x59 finalize frame carries body composition only when the user is registered on the scale via the Beurer/Sanitas app. In your capture all composition bytes were zero, which is why the fat/water/muscle metrics also looked nonsensical.

Fix

Branch fix/issue-112-sbf70-frame parses the SBF70 variant correctly and applies a 3-reading stability window (0.3 kg tolerance) so the scale's initial metadata frame does not complete the measurement early.

Docker image building now. It will be published as ghcr.io/kristianp26/ble-scale-sync:issue-112-fix in ~10 minutes.

How to test

docker pull ghcr.io/kristianp26/ble-scale-sync:issue-112-fix

docker run --rm -it --network host --cap-add NET_ADMIN --cap-add NET_RAW \
  --group-add 112 -v /var/run/dbus:/var/run/dbus:ro \
  -v $PWD/config.yaml:/app/config.yaml:ro \
  -e DEBUG=true \
  ghcr.io/kristianp26/ble-scale-sync:issue-112-fix

Step on, wait for the scale to settle, step off. You should now see your real weight (around 106 kg) instead of 12.80 kg.

About the body composition

Even with the weight fix, fat/water/muscle will still show computed BIA values (not the scale's own composition) because your 0x59 frame contained all zeros. The SBF70 only emits its internal composition when the user is registered in its user slot through the Beurer/Sanitas app. If you want the scale's native composition in addition to weight, register your profile on the scale via the app and rerun. Otherwise the BIA calculation from weight and impedance is what you will get, which is consistent with other scales in the app.

Let me know how it goes.

[flow778]

Hello @KristianP26,

The weight now looks good and is being transmitted to Home Assistant via MQTT.
Thank you very much for your effort. I’ve bought you a coffee.

Best regards,

flow778