Dallas Temperature Sensor

The dallas sensor allows you to use ds18b20 and similar sensors. First, you need to define a dallas sensor component. The dallas sensor component (or “hub”) is an internal model that defines which pins the ds18b20 sensors are connected to. This is because with these sensors you can actually connect multiple sensors to a single pin and use them all at once.

To initialize a sensor, first supply either address or index to identify the sensor.

../../../_images/dallas-wired.jpg

Wired Version of the DS18b20 One-Wire Temperature Sensor.

../../../_images/temperature.png
# Example configuration entry
dallas:
  - pin: GPIO23

# Individual sensors
sensor:
  - platform: dallas
    address: 0x1C0000031EDD2A28
    name: "Living Room Temperature"

Configuration variables:

  • address (Required, int): The address of the sensor. Use either this option or index.
  • index (Required, int): The index of the sensor starting with 0. So the first sensor will for example have index 0. It’s recommended to use address instead.
  • resolution (Optional, int): An optional resolution from 8 to 12. Higher means more accurate. Defaults to the maximum for most dallas temperature sensors: 12.
  • dallas_id (Optional, ID): The ID of the dallas hub. Use this if you have multiple dallas hubs.
  • id (Optional, ID): Manually specify the ID used for code generation.
  • All other options from Sensor and MQTT Component.

Getting Sensor IDs

It is highly recommended to use the address attribute for creating dallas sensors, because if you have multiple sensors on a bus and the automatic sensor discovery fails, all sensors indices will be shifted by one. In order to get the address, simply start the firmware on your device with a configured dallas hub and observe the log output (the log level must be set to at least debug!). Note that you don’t need to define the individual sensors just yet, as the scanning will happen even with no sensors connected. For example with this configuration:

# Example configuration entry
dallas:
  - pin: GPIO23

# Note you don't have to add any sensors at this point

You will find something like this:

../../../_images/dallas-log.png

Now we can add the individual sensors to our configuration:

# Example configuration entry
dallas:
  - pin: GPIO23

sensor:
  - platform: dallas
    address: 0xA40000031F055028
    name: "Temperature #1"
  - platform: dallas
    address: 0xDD0000031EFB0428
    name: "Temperature #2"
  - platform: dallas
    # ...

Next, individually warm up or cool down the sensors and observe the log again. You will see the outputted sensor values changing when they’re being warmed. When you’re finished mapping each address to a name, just change the Temperature #1 to your assigned names and you should be ready.