LSC Smart Connect Power Plug 3202087.2

Overview

The LSC Smart Connect Power Plug 3202087.2 is a 2.4 GHz EU smart plug with a single relay, a front-panel button, and BL0937-based energy monitoring. The unit documented here uses a Tuya T1-2S-NL module.

Product Images

Board and Module Photos

The module photos are useful because the side castellations are clearly labelled. On this board you can see 3V3, GND, RX1, TX1, P9, and P24 on one side, and CEN, P1 (ADC/SEL), P8, P6, and P26 on the other.

Opening and Flashing

This device is not flashable without opening the enclosure. To install ESPHome you need to disassemble the plug and solder temporary wires to the UART pads.

1. Unplug the device from mains power before opening it.
2. Solder to 3V3, GND, RX1, and TX1 on the module or its matching breakout pads on the PCB.
3. Cross the UART lines when connecting your adapter: adapter TX to device RX1, adapter RX to device TX1.
4. Use 3.3 V UART levels only. Many USB-to-UART adapters can handle the serial connection but cannot supply enough current to power the whole board reliably, so if flashing is unstable or the board keeps resetting, power the PCB from a separate regulated 3.3 V supply and connect its GND to the adapter GND.
5. If your flashing workflow needs a reset line, the board also exposes CEN.

Because the Wi-Fi status LED is wired to P11 / TX1, the example configuration disables UART logging with logger: baud_rate: 0.

GPIO Pinout

The PCB silkscreen is clear and matches the working ESPHome mapping below.

Pin	PCB silk	Module silk	Function
P26	S1	P26	Front button
P6	CF	P6	BL0937 CF
P8	CF1	P8	BL0937 CF1
P1	SEL	P1	BL0937 SEL (inverted)
P11	D-WIFI	TX1	Wi-Fi status LED
P9	D-K	P9	Relay LED
P24	K1	P24	Relay

Basic Configuration

The base configuration below covers the relay, button, both LEDs, the internal temperature sensor, and BL0937 power monitoring. Add your own wifi:, api:, and ota: sections before flashing. The example also leaves out passwords and !secret references so you can merge it into your own setup and fill in your local credentials separately.

https://github.com/esphome/devices.esphome.io/blob/main/src/docs/devices/LSC-Plug-3202087.2/config.yaml

substitutions:
  name: lsc-plug-3202087-2
  friendly_name: LSC Smart Power Plug 3202087.2
  current_resistor: "0.00107"
  voltage_divider: "803.059"

esphome:
  name: ${name}
  friendly_name: ${friendly_name}
  platformio_options:
    custom_versions.beken-bdk: 3.0.78

bk72xx:
  board: generic-bk7238-tuya
  family: BK7238
  framework:
    version: 0.0.0
    source: https://github.com/libretiny-eu/libretiny#feature/bk7238

logger:
  baud_rate: 0

wifi:
  ap:

status_led:
  pin:
    number: P11
    inverted: true

output:
  - platform: gpio
    id: relay_led_output
    pin:
      number: P9
      inverted: true

switch:
  - platform: gpio
    name: "None"
    id: relay_1
    pin:
      number: P24
    restore_mode: RESTORE_DEFAULT_OFF
    on_turn_on:
      - output.turn_on: relay_led_output
    on_turn_off:
      - output.turn_off: relay_led_output

binary_sensor:
  - platform: gpio
    name: Button
    id: button_1
    internal: true
    pin:
      number: P26
      inverted: true
      mode: INPUT_PULLUP
    on_press:
      - switch.toggle: relay_1

sensor:
  - platform: internal_temperature
    name: Internal Temperature
    entity_category: diagnostic

  - platform: hlw8012
    model: BL0937
    sel_pin:
      number: P1
      inverted: true
    cf_pin:
      number: P6
      inverted: true
    cf1_pin:
      number: P8
      inverted: true
    current_resistor: ${current_resistor}
    voltage_divider: ${voltage_divider}
    current:
      name: Current
      id: plug_current
      unit_of_measurement: A
      accuracy_decimals: 3
      filters:
        - multiply: 0.450158
    voltage:
      name: Voltage
      id: plug_voltage
      unit_of_measurement: V
      accuracy_decimals: 1
    power:
      name: Power
      id: plug_power
      unit_of_measurement: W
      accuracy_decimals: 1
    energy:
      name: Energy
      id: plug_energy
      unit_of_measurement: kWh
      accuracy_decimals: 3
      filters:
        - multiply: 0.001
    update_interval: 2s
    change_mode_every: 2

Advanced Configuration

The advanced fragment below adds common diagnostic entities on top of the base config. Merge it into your own setup after you add networking.

https://github.com/esphome/devices.esphome.io/blob/main/src/docs/devices/LSC-Plug-3202087.2/advanced.yaml

binary_sensor:
  - platform: status
    name: Status
    entity_category: diagnostic

sensor:
  - platform: wifi_signal
    name: WiFi Signal
    entity_category: diagnostic
    update_interval: 60s

  - platform: uptime
    name: Uptime
    entity_category: diagnostic

text_sensor:
  - platform: wifi_info
    ip_address:
      name: IP Address
    ssid:
      name: Connected SSID

button:
  - platform: restart
    name: Restart
    entity_category: diagnostic

BK7238 Support Status

At the time of writing, BK7238 support is still being worked on in ESPHome/LibreTiny. The example configuration therefore pins the Beken SDK version and pulls LibreTiny from the BK7238 feature branch:

https://github.com/esphome/devices.esphome.io/blob/main/src/docs/devices/LSC-Plug-3202087.2/bk7238-note.yaml

esphome:
  platformio_options:
    custom_versions.beken-bdk: 3.0.78

bk72xx:
  framework:
    version: 0.0.0
    source: https://github.com/libretiny-eu/libretiny#feature/bk7238

Once BK7238 support lands in regular releases, these overrides may no longer be required.

BL0937 Calibration

Start with the values shown in config.yaml and calibrate them with a trusted external meter plus a resistive load such as a kettle or heater.

1. Adjust voltage_divider until the reported voltage matches your reference meter.
2. Adjust current_resistor until current and power match under the same load.
3. Re-check with a second resistive load and fine-tune if needed.

The 0.450158 current filter used in the example config is worth keeping. In practice it is best to leave that factor in place, calibrate voltage_divider first, and only then fine-tune current_resistor.