Home Assistant

One wire Sensor

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

Supported devices:

The 1-Wire bus can be connected directly to the IO pins of Raspberry Pi or using dedicated interface adapter (e.g DS9490R).

Raspberry Pi setup

In order to setup 1-Wire support on Raspberry Pi, you’ll need to edit /boot/config.txt following this documentation. Don’t use the mount_dir option.

Interface adapter setup

When an interface adapter is used, sensors can be accessed on Linux hosts via owfs 1-Wire file system. When using an interface adapter and the owfs, the mount_dir option must be configured to correspond a directory, where owfs device tree has been mounted.

This component has been modified to work 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 home-assistant.io/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.

Home Assistant setup

To enable One wire sensors in your installation, add the following to your configuration.yaml file:

# Example configuration.yaml entry
sensor:
  - platform: onewire
    names:
      some_id: your name

Configuration variables:

  • names array (Optional): ID and friendly name of your sensors.
  • mount_dir (Optional): Location of device tree if owfs driver used.