Feit Electric Smart Dimmers

Device Type: dimmer

Electrical Standard: us

Board: bk72xx

I purchased this at Costco in Canada in November of 2022 and then again in November of 2024. The Costco item number was 1734165.

It is hold together with screws, making it very easy to open and flash.

First, I took the unit apart. Then I soldered pin headers onto the board. I took 3v3 and gnd from a nearby ESP32 devkit and connected it to my computer.

You also need to solder a wire to the NRST pad on the back side of the board. This is the trickiest part as the pad is small. It is possible to remove the pad entirely from the board rendering it unusable so be a bit careful and if you've been working with the board for a bit and it won't take the solder or won't enter programming mode it's possible that you removed the pad.

Dumping original firmware

In the plastic socket on the board is a place for ground and 3v3. Connect NRST to gnd as you provide power to the board to put the board in flash mode. Once you disconnect ground from NRST, the board "boots". The board needs to be in flash mode to read the flash or to write the flash but once the process starts you can disconnect ground from NRST.

I don't like to solder onto that pad because it can pull the pad off. This makes the board undlashable. Instead, I hold (with fingers) a ground-connected wire to NRST, power the board, press enter on the command. Then I can let go.

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ltchiptool flash read beken-72xx ./dimmer1

Installing ESPhome

I used ltchiptool's UPK2ESPHome to parse the firmware. The result is the configuration below. Put that config into a .yml file and compile the firmware:

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esphome compile dimmer.yml

Next, write that firmware:

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ltchiptool flash write .esphome/build/dimmer/.pioenvs/dimmer/esphome_2024.10.0_generic-bk7231n-qfn32-tuya_bk7231n_lt1.7.0.uf2 --device=/dev/tty.usbserial-0001

Basic Configuration (hardware only)

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bk72xx:
  board: generic-bk7231n-qfn32-tuya

uart:
  rx_pin: RX1
  tx_pin: TX1
  baud_rate: 9600

tuya:
  # DPIDs processed from schema model: 000003w4ro

light:
- platform: tuya
  id: dimmer_switch
  name: "Dimmer Switch"
  switch_datapoint: 1
  dimmer_datapoint: 2
  min_value_datapoint: 3
  max_value: 1490

number:
  - platform: tuya
    number_datapoint: 2
    name: Brightness
    min_value: 10
    max_value: 1490
    step: 1
  - platform: tuya
    number_datapoint: 3
    name: Brightness Min
    min_value: 10
    max_value: 1000
    step: 1
  - platform: tuya
    number_datapoint: 5
    name: Brightness Max
    min_value: 700
    max_value: 1490
    step: 1

select:
  - platform: tuya
    enum_datapoint: 4
    name: Led Type
    optimistic: true
    options:
      0: Led
      1: Incandescent
      2: Halogen
  - platform: tuya
    enum_datapoint: 101
    name: Switch LED Brightness
    optimistic: true
    options:
      0: "Off"
      1: Low
      2: High
  - platform: tuya
    enum_datapoint: 102
    name:  On Control
    optimistic: true
    options:
      0: Gradual
      1: Instant
      2: Switch