ESPHome DALI Master Component

This component implements a DALI master that can talk to devices on a DALI bus.

Supported Features:

• Automatic device discovery & address assignment
• DALI dimmer support
  • brightness control
  • colour temperature control
• Broadcast or short address
• Query device capabilities
  • dali.light component automatically enables colour temperature if device reports the capability
• DALI parameter configuration
  • Fade rate/time
  • Brightness curve (log/linear)

Usage:

At first, load the external component from github:

external_components:
  - source: github://jorticus/esphome-dali@master
    components: [dali]

Lights can be automatically discovered on the bus by simply defining a dali bus component:

# bit-banged 1200 baud DALI bus
dali:
  id: dali_bus
  tx_pin: 4
  rx_pin: 12

  # Lights will be created for each detected DALI light device
  discovery: true

  # Devices will be automatically assigned a short address if they do not have one
  initialize_addresses: true

If you do not want to use automatic discovery, or want to customize a specific light, you can specify the light component with an address like so:

light:
- platform: dali
  id: dali_light
  name: "DALI Light"
  address: 0 # Short address, group address, or omit for broadcast
  restore_mode: RESTORE_DEFAULT_ON 

  # Set the brightness curve on the device
  brightness_curve: LOGARITHMIC # (default)

  # Force a specific color mode, irrespective of what the device claims.
  color_mode: COLOR_TEMPERATURE # (default: auto detect)

  # Update the fade time/rate on the device
  fade_time: 1s
  fade_rate: 44724  # steps/second

Future Work:

• Support scenes & groups
• Allow configuration of DALI device parameters
• Automatic device discovery
• Automatic address assignment
• Support for RGB(W) devices
• Hardware protocol support (no bit banging)

Components

dali

The main dali copmonent implements the low level bus interface via bit-bang protocol.

The dali bus implements a simple bit-banged protocol, but you can extend it with a better implementation for your platform (eg, DMA, interrupt based).

dali:
  tx_pin: <transmit pin>
  rx_pin: <receive pin>

dali.light

The dali light component supports both specific device addressing (short address), addressing groups, and broadcast.

NOTE: Querying capabilities is only supported if a specific device address is provided.

If an address is provided, it will query the device for its capabilities, and enable the appropriate features such as colour temperature control.

light:
- platform: dali
  address: <short address, group address, or broadcast(0xFF)>

  # For UI display purposes only:
  cold_white_color_temperature: 6000K
  warm_white_color_temperature: 2700K

dali.output

The dali output component implements a float output that broadcasts the value as a brightness level

output:
  - platform: dali

It has no configurable parameters.

Wiring

The minimum viable schematic for interfacing with the bus looks like this:

This is NOT compliant with the spec, but will work...

The spec requires 16V with a fast-response ~200mA current limiter implemented with a BJT current source, and dual opto-isolators. However since the bus is connected to a non-isolated power supply, we can get away without opto-isolation, except as convenience for converting the DALI voltage levels to a safe 3.3 logic level.

There are other ways to implement the current limiter too, as long as they have a quick response time. I succsessfully used an opamp current limiting circuit as I didn't have an LM317 or BJT on hand. It has been noted elsewhere that if using a LM317, it MUST be an on-brand chip, and preferably the LM317DCYR from Texas Instruments.

I will later be releasing a Kicad project for a DALI bus adapter board that more closely follows the spec.

Hardware Adapters

WaveShare sells a cheap DALI board for use with their ESP32-S3-Pico devboard, and is probably the easiest way to get up and going with this component:

https://www.waveshare.com/pico-dali2.htm

https://www.waveshare.com/wiki/Pico-DALI2

Let me know if you have success with this! I am using a custom design that is more or less the same as this, but also injects power onto the bus.

Device Support

The following devices have been tested with this library:

• EOKE BK-DWL060-1500AD (63W CCT LED Driver, min brightness 86)
• LTECH LM-75-24-G2D2 (75W CCT LED Driver, 1000:1 dimming range)
• LTECH MT-100-650-D2D1-A1 (48VDC CCT LED Driver PCB Module)