Arlec PC399HA Plug

The Arlec PC399HA power plug is part of the Grid Connect ecosystem and is sold at Bunnings in Australia and New Zealand.

As at the time of writing, they can sometimes be flashed without disassembly or soldering using tuya-convert. Newer versions cannot yet be flashed without opening the device.

To flash the device manually the unit needs to be opened and then flashed over the UART connection. An example video on youtube shows how to wire this into a UART adaptor.

GPIO Pinout

Pin	Function
GPIO03	Button
GPIO04	BL0937 CF
GPIO05	BL0937 CF1
GPIO12	BL0937 SEL
GPIO13	Blue LED (Inverted: true)
GPIO14	Relay

Getting it up and running

Tuya Convert

These switches are Tuya devices, so if you don't want to open them up to flash directly, you can use tuya-convert to initially get ESPHome onto them. After that, you can use ESPHome's OTA functionality to make any further changes.

• Put the switch into "smartconfig" / "autoconfig" / pairing mode by holding any button for about 5 seconds.
• The status LED blinks rapidly to confirm that it has entered pairing mode.

Basic Configuration

substitutions:
  device_name: "arlec_PC399HA_1"
  name: "ARLEC PC399HA 1"

esphome:
  name: ${device_name}
  comment: ${name}
  friendly_name: ${name}

esp8266:
  board: esp01_1m

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "api_password"

ota:
  password: "ota_password"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  ap:

captive_portal:

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO3
      inverted: True
      mode: INPUT_PULLUP
    name: ${name} button
    filters:
      delayed_on_off: 100ms # Debouncing
    on_press:
      then:
        - switch.toggle: relay

switch:
  - platform: gpio
    pin: GPIO14
    name: "${name}"
    id: relay
    restore_mode: always on
    icon: mdi:power-socket-au
    on_turn_on:
      then:
        - output.turn_on: button_led
    on_turn_off:
      then:
        - output.turn_off: button_led

output:
  - platform: gpio
    id: button_led
    pin:
      number: GPIO13
      inverted: yes

sensor:
  - platform: hlw8012
    model: BL0937
    sel_pin:
      number: GPIO12
      inverted: true
    cf_pin: GPIO04
    cf1_pin: GPIO05
    voltage_divider: 1650 # You may need to adjust this to be accurate
    current:
      name: "${name} Current"
      accuracy_decimals: 3
    voltage:
      name: "${name} Voltage"
      accuracy_decimals: 2
    power:
      name: "${name} Power"
      id: totalMediaWatts
    energy:
      name: "${name} Energy"
    update_interval: 10s