DS248x 1-Wire Bus Master

The ds248x component supports DS2482-100, DS2482-101, DS2482-800, and DS2484 I2C-to-1-Wire bridge chips. Configure the bridge itself under ds248x, then create one or more 1-Wire bus entries using the ds248x platform.

NOTE

Every ds248x entry requires a type:. The number of available channels is derived from the selected chip type, so channel_count is not used.

TIP

If you are using a DS2484 chip with the new unified component, configure it here with type: ds2484. The legacy 1-Wire Bus via DS2484 page documents the older one_wire platform.

Supported Hardware

• DS2482-100: Single-channel 1-Wire master.
• DS2482-101: Single-channel 1-Wire master with sleep pin support.
• DS2482-800: 8-channel 1-Wire master.
• DS2484: Single-channel 1-Wire master with adjustable timing and active pullup resistance settings.

Component/Hub

The ds248x component is an I²C-to-1-Wire bridge. An I²C Bus must be defined in your configuration to use it. The bridge itself is configured under ds248x; each entry then exposes one or more 1-Wire buses via the ds248x platform.

# Example for a single-channel DS2482-100
ds248x:
  - id: hub_1wire
    type: ds2482-100

one_wire:
  - platform: ds248x
    ds248x_id: hub_1wire
    id: hub_1wire_bus

sensor:
  - platform: dallas_temp
    one_wire_id: hub_1wire_bus
    address: 0x1C0000031EDD2A28
    name: Temperature

Configuration variables

• type (Required, string): The DS248x chip variant. One of ds2482-100, ds2482-101, ds2482-800, or ds2484.
• address (Optional, int): The I²C address of the device. Defaults to 0x18.
• active_pullup (Optional, boolean): Enable the active pullup feature. Useful for long lines or heavier bus loads. Defaults to false.
• sleep_pin (Optional, Pin Schema): A GPIO pin connected to the SLPZ pin. Only available for ds2482-101 and ds2484.
• bus_sleep (Optional, boolean): Put the 1-Wire bus to sleep when not in use. Only available for ds2482-101 and ds2484. Defaults to false.
• hub_sleep (Optional, boolean): Put the bridge chip to sleep when not in use. Requires sleep_pin and is only available for ds2482-101 and ds2484. Defaults to false.
• id (Optional, ID): Manually specify the ID for this DS248x bridge if you need more than one.
• i2c_id (Optional, ID): The ID of the I²C bus to use. Required if you have configured multiple I²C buses.

DS2484-Specific Options

These options are only available when type: ds2484 is selected. See the datasheet for the exact timing and resistance mappings.

• reset_low_time (Optional, int): Adjust the reset low time (tRSTL). Value from 0 to 15.
• master_sample_time (Optional, int): Adjust the master sample time (tMSP). Value from 0 to 15.
• write_0_low_time (Optional, int): Adjust the write-0 low time (tW0L). Value from 0 to 15.
• recovery_time (Optional, int): Adjust the recovery time (tREC0). Value from 0 to 15.
• active_pullup_resistance (Optional, string): The active pullup resistance. One of 500ohm or 1000ohm.

1-Wire Bus

The one_wire platform named ds248x creates the actual 1-Wire bus instances used by devices such as dallas_temp. Create one entry per channel you want to use.

# Example for an 8-channel DS2482-800
ds248x:
  - id: ds2482_hub
    type: ds2482-800

one_wire:
  - platform: ds248x
    ds248x_id: ds2482_hub
    channel: 0
    id: ow_ch0
  - platform: ds248x
    ds248x_id: ds2482_hub
    channel: 7
    id: ow_ch7

sensor:
  - platform: dallas_temp
    one_wire_id: ow_ch0
    address: 0x1C0000031EDD2A28
    name: Temperature CH0
  - platform: dallas_temp
    one_wire_id: ow_ch7
    address: 0x2800000123456789
    name: Temperature CH7

# Example for a DS2482-101 with sleep support
ds248x:
  - id: ds2482_101_hub
    type: ds2482-101
    sleep_pin: GPIOXX
    bus_sleep: true
    hub_sleep: true

one_wire:
  - platform: ds248x
    ds248x_id: ds2482_101_hub
    id: ds2482_101_bus

sensor:
  - platform: dallas_temp
    one_wire_id: ds2482_101_bus
    address: 0x1C0000031EDD2A28
    name: Temperature

# Example for a DS2484 with advanced timing options
ds248x:
  - id: ds2484_hub
    type: ds2484
    active_pullup: true
    active_pullup_resistance: 500ohm
    reset_low_time: 8
    master_sample_time: 8
    write_0_low_time: 8
    recovery_time: 8

one_wire:
  - platform: ds248x
    ds248x_id: ds2484_hub
    id: ds2484_bus

Configuration variables

• ds248x_id (Optional, ID): The ID of the parent ds248x component. Required if there is more than one ds248x component.
• channel (Optional, int): The channel index to use. Defaults to 0. For ds2482-800, valid values are 0 to 7. For ds2482-100, ds2482-101, and ds2484, leave this omitted or set it to 0.
• id (Optional, ID): Manually specify the ID of the 1-Wire bus. Required if you have configured multiple 1-Wire buses.

Finding Sensor Addresses

To find the addresses of your 1-Wire devices, upload a configuration with the ds248x and one_wire components set up and check the logs during boot. Scanning also works before you define any sensor entries.

[I][one_wire:161]:   Found device 0x1C0000031EDD2A28

Copy the discovered 64-bit address into the matching device configuration, for example in dallas_temp.

I2C Address Reference

The I2C address depends on the chip variant and the state of its address pins.

Chip	Address Pins	Default Address	Address Range
DS2482-100	AD0, AD1	0x18	0x18 to 0x1B
DS2482-101	AD0	0x18	0x18 to 0x19
DS2482-800	AD0, AD1, AD2	0x18	0x18 to 0x1F
DS2484	AD0, AD1	0x18	0x18 to 0x1B

See Also

• 1-Wire Bus
• I²C Bus
• Dallas Temperature Sensor
• Guidelines for Reliable Long Line 1-Wire Networks
• API Reference: one_wire_bus.h