---
title: 1-Wire
description: Instructions on how to integrate One wire (1-wire) sensors into Home Assistant.
ha_category:
  - DIY
ha_release: 0.12
ha_iot_class: Local Polling
ha_config_flow: true
ha_codeowners:
  - '@garbled1'
  - '@epenet'
ha_domain: onewire
ha_quality_scale: gold
ha_platforms:
  - binary_sensor
  - diagnostics
  - sensor
  - switch
ha_integration_type: hub
---

<div class='note warning'>

Using this integration via the SysBus is deprecated and will be removed in Home Assistant Core 2022.6.

For more information see: [Architectural Decision Record 0019](https://github.com/home-assistant/architecture/blob/master/adr/0019-GPIO.md).

</div>

The `onewire` platform supports sensors which that using the One wire (1-wire) bus for communication.

Every 1-wire device has a (globally) unique ID that identifies the device on the bus. The first two digits identify a device family and the last 14 digits are a globally unique number given to it during manufacturing.

Different families have different functionality and can measure different quantities.

Each 1-wire component data sheet describes the different properties the component provides. The [owfs software](https://github.com/owfs/owfs) adds some extra tools to make it easier for DIY implementers to use the component. 

### Supported devices:

#### Binary sensors:

| Family | Device           | Physical Quantity  |
| -------|:-----|:-----|
| 12     | [DS2406](https://datasheets.maximintegrated.com/en/ds/DS2406.pdf)  | 2 sensed (sensed.A/B) <sup>[4](#note_4)</sup> |
| 29     | [DS2408](https://datasheets.maximintegrated.com/en/ds/DS2408.pdf)  | 8 sensed (sensed.0-7) <sup>[4](#note_4)</sup> |
| 3A     | [DS2413](https://datasheets.maximintegrated.com/en/ds/DS2413.pdf)  | 2 sensed (sensed.A/B) <sup>[4](#note_4)</sup> |
| EF     | [HobbyBoard](https://hobbyboards.com/)                             | Hub Branch State <sup>[3](#note_3) [4](#note_4)</sup> |

#### Sensors:

| Family | Device           | Physical Quantity  |
| -------|:-----|:-----|
| 10     | [DS18S20](https://www.maximintegrated.com/en/products/sensors/DS18S20.html)  | Temperature                     |
| 12     | [DS2406](https://datasheets.maximintegrated.com/en/ds/DS2406.pdf)            | Temperature and pressure when using TAI-8570 <sup>[1](#note_1)</sup> |
| 1D     | [DS2423](https://datasheets.maximintegrated.com/en/ds/DS2423.pdf)            | Counter                         |
| 22     | [DS1822](https://datasheets.maximintegrated.com/en/ds/DS1822.pdf)            |                                 |
| 26     | [DS2438](https://datasheets.maximintegrated.com/en/ds/DS2438.pdf)            | Temperature, Voltage, Current (pressure when using B1-R1-A, illuminance when using S2-R1-A, humidity when using compatible Honeywell or Humirel sensor) <sup>[2](#note_2)</sup> |
| 28     | [DS18B20](https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf)          | Temperature                     |
| 30     | [DS2760](https://pdfserv.maximintegrated.com/en/ds/DS2760.pdf)            | Temperature, Voltage, Thermocouple Type K <sup>[2](#note_2)</sup> |
| 3B     | [DS1825](https://datasheets.maximintegrated.com/en/ds/DS1825.pdf)            | Temperature                     |
| 42     | [DS28EA00](https://datasheets.maximintegrated.com/en/ds/DS28EA00.pdf)        | Temperature                     |
| 7E     | [EDS00xx](https://www.embeddeddatasystems.com/assets/images/supportFiles/manuals/EN-UserMan%20%20OW-ENV%20Sensor%20v13.pdf)        | Temperature/Humidity/Barometric pressure/Light <sup>[6](#note_6)</sup>|
| EF     | [HobbyBoard](https://hobbyboards.com/)                                       | Temperature, Humidity, Moisture, Wetness <sup>[3](#note_3)</sup> |  

#### Switches:

| Family | Device           | Physical Quantity  |
| -------|:-----|:-----|
| 05     | [DS2405](https://datasheets.maximintegrated.com/en/ds/DS2405.pdf)  | 1 PIO <sup>[4](#note_4)</sup> |
| 12     | [DS2406](https://datasheets.maximintegrated.com/en/ds/DS2406.pdf)  | 2 latches (latch.A/B) and 2 PIOs (PIO.A/B) <sup>[4](#note_4)</sup> |
| 29     | [DS2408](https://datasheets.maximintegrated.com/en/ds/DS2408.pdf)  | 8 latches (latch.0-7) and 8 PIOs (PIO.0/7) <sup>[4](#note_4)</sup> |
| 3A     | [DS2413](https://datasheets.maximintegrated.com/en/ds/DS2413.pdf)  | 2 PIOs (PIO.A/B) <sup>[4](#note_4)</sup> |
| EF     | [HobbyBoard](https://hobbyboards.com/)                             | Hub Branch Enable, Moisture Sensor Type <sup>[3](#note_3) [4](#note_4)</sup> |

#### Bridges:

| Family | Device           | Physical Quantity |
| -------|:-----|:-----|
| 1F     | [DS2409](https://datasheets.maximintegrated.com/en/ds/DS2409.pdf)  | None <sup>[5](#note_5)</sup>


Notes:

- <a name="note_1">The TAI-8570</a> Pressure Sensor is based on a 1-wire composite device by AAG Electronica. It contains, above 1-wire components, also a barometer, hygrometer and illuminance sensors. This onewire platform can read and present values from that device, but the sensors will default to disabled <sup>[4](#note_4)</sup>.

- <a name="note_2">For hobbyists</a>, it is quite common to use DS2438 or DS2760 families of Smart Battery Monitor as a multipurpose measurement node that can place temperature, humidity, current, thermocouple temperature, and luminosity on the 1-wire bus by just adding some standard components to the DS2438 or DS2760. For different component types, there are ready-made algorithms implemented in owfs. Those are exposed by the owfs software and can be read by this platform. The B1-R1-A/pressure is exposed as a barometric pressure sensor. S2-R1-A/illuminance is presented as an illuminance sensor. For a more detailed description of these properties, refer to the owfs documentation [DS2438](https://owfs.org/index_php_page_ds2438.html), [DS2760](https://owfs.org/index_php_page_ds2760.html).
  For these components, the more basic quantities (temperature, VAD, VDD and IAD) are exported as separate sensors. Please note that some of the sensors will default to disabled <sup>[4](#note_4)</sup>.

- <a name="note_3">Hobbyboards</a> is a company that has been selling DIY boards of different kinds. The company has been away from the market for some time, so no reference to the boards can be made. This platform has an implementation for some of those.

- <a name="note_4">Some sensors are disabled by default</a> to avoid overloading the bus. These can be activated by opening the integrations page in your configuration, listing your 1-Wire integration devices and updating the entity.

- <a name="note_5">Bridge devices have no sensors</a>. The `aux` and `main` branches are searched for additional 1-wire devices during discovery.  

- <a name="note_6">Multisensors manufactured by Embedded Data Systems</a>. Currently only EDS0066 (temperature/barometric pressure) and EDS0068 (temperature/humidity/barometric pressure/light) are supported.  
## Interfacing with the 1-wire bus

The 1-Wire bus can be connected with a remote 1-wire host over a network connection using owfs and owserver.

## Interface adapter setup

`owserver` on Linux hosts is part of the [owfs 1-Wire file system](https://owfs.org/). When a 1-wire interface adapter is used, you can access sensors on a remote or local Linux host that is running `owserver`. `owserver` by default runs on port 4304. Use the `host` option to specify the host or IP of the remote server, and the optional `port` option to change the port from the default.

{% include integrations/config_flow.md %}

### Entities and attributes

Upon startup of the platform, the 1-wire bus is searched for available 1-wire devices. On Bridge devices, the `aux` and `main` branches are recursively searched. For each device that this platform handles (see list of supported devices above), the platform adds one sensor for each physical quantity it measures. The name of the sensor is the device ID with the physical quantity it measures appended. Unsupported sensors are noted with a warning message in the log.

`sensor.28.FF5C68521604_temperature`

Each sensor will present its value in the state variable and for presentation purposes, rounded to one decimal for analog values and as integers for counts.

Each sensor also exposes some additional attributes.

```alpha
device_file: /28.FF5C68521604/temperature              << Device path in owfs file system (or on Rpi system directory)
raw_value: 31.9375                                     << The raw measurement numbers as red from device. Not rounded.
unit_of_measurement: °C                              
friendly_name: 28.FF5C68521604 Temperature
```

### Units with multiple sensors

This platform works with devices with multiple sensors, which will cause a discontinuity in recorded values. Existing devices will receive a new ID and therefore show up as new devices.
If you wish to maintain continuity, it can be resolved in the database by renaming the old devices to the new names.

Connect to your database using the instructions from [Database section](/docs/backend/database/). Check the names of sensors:

```sql
SELECT entity_id, COUNT(*) as count FROM states GROUP BY entity_id ORDER BY count DESC LIMIT 10;
```

Alter the names of sensors using the following examples:

```sql
UPDATE states SET entity_id='sensor.<sensor_name>_temperature' WHERE entity_id LIKE 'sensor.<sensor_name>%' AND attributes LIKE '%\u00b0C%';
UPDATE states SET entity_id='sensor.<sensor_name>_pressure' WHERE entity_id LIKE 'sensor.<sensor_name>%' AND attributes LIKE '%mb%';
UPDATE states SET entity_id='sensor.<sensor_name>_humidity' WHERE entity_id LIKE 'sensor.<sensor_name>%' AND attributes LIKE '%%%' ESCAPE '';
```

Remember to replace `<sensor_name>` with the actual name of the sensor, as seen in the `SELECT` query.