Gosund SP111 v1.1 or Nous A1 power montor/switch plug

Removing your smart switch, or at least IOT device from the cloud. Not sure why everyone keeps calling them smart, there's nothing smart about these devices. What wasn't clear to me in the beginning was that you needed to calibrate every sensor. See not so smart after all.

Requirements

• FTDI USB To TTL 3.3V & 5.5V Serial Adapter + Cable
• esptool
• Jumper wires
• Firmware binary

Generate firmware with ESPHome

substitutions:
  devicename: "whatever"
  upper_devicename: "Gosund SP111"
  # Higher value gives lower watt readout
  current_res: "0.00280"
  # Lower value gives lower voltage readout
  voltage_div: "775"
  wifi_ssid: "wifi_ssid"
  wifi_pass: "wifi_password"
  fallback_pass: "wifi_fallback_password"
  api_pass: "api_password"
  ota_pass: "ota_password"

esphome:
  name: $devicename
  platform: ESP8266
  arduino_version: 2.5.1
  board: esp8285

# Enable logging
logger:
  baud_rate: 0

# Enable Home Assistant API
api:
  password: "${api_pass}"

# Enable over the air updates
ota:
  password: "${ota_pass}"

wifi:
  ssid: "${wifi_ssid}"
  password: "${wifi_pass}"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "${devicename} Fallback Hotspot"
    password: "${fallback_pass}"

# see: https://esphome.io/components/time.html
time:
  - platform: homeassistant
    id: homeassistant_time

# Enable Web server
web_server:
  port: 80

text_sensor:
  - platform: version
    name: "${devicename} - Version"
    icon: mdi:cube-outline

binary_sensor:
  - platform: status
    name: "${devicename} - Status"
    device_class: connectivity

  # toggle relay on/off
  - platform: gpio
    pin:
      number: GPIO13
      mode: INPUT_PULLUP
      inverted: True
    id: "${devicename}_button_state"
    on_press:
      - switch.toggle: button_switch

sensor:
  - platform: wifi_signal
    name: "${devicename} - Wifi Signal"
    update_interval: 60s
    icon: mdi:wifi

  - platform: uptime
    name: "${devicename} - Uptime"
    update_interval: 60s
    icon: mdi:clock-outline

  - platform: total_daily_energy
    name: "${devicename} - Todays Usage"
    power_id: "power_wattage"
    filters:
      # Multiplication factor from W to kW is 0.001
      - multiply: 0.001
    unit_of_measurement: kWh
    icon: mdi:calendar-clock

  - platform: adc
    pin: VCC
    name: "${devicename} - VCC Volt"
    icon: mdi:flash-outline

  - platform: hlw8012
    sel_pin:
      number: GPIO12
      inverted: True
    cf_pin: GPIO05
    cf1_pin: GPIO04
    change_mode_every: 4
    current_resistor: ${current_res}
    voltage_divider: ${voltage_div}
    update_interval: 3s

    current:
      name: "${devicename} - Ampere"
      unit_of_measurement: A
      accuracy_decimals: 3
      icon: mdi:current-ac

    voltage:
      name: "${devicename} - Volt"
      unit_of_measurement: V
      accuracy_decimals: 1
      icon: mdi:flash-outline

    power:
      name: "${devicename} - Watt"
      unit_of_measurement: W
      id: "power_wattage"
      icon: mdi:gauge

status_led:
  pin:
    number: GPIO00
    inverted: True
  id: led_red

output:
  - platform: gpio
    pin: GPIO02
    inverted: True
    id: led_blue

switch:
  - platform: template
    name: "${devicename} - Switch"
    icon: mdi:power
    optimistic: true
    id: button_switch
    turn_on_action:
      - switch.turn_on: relay
    turn_off_action:
      - switch.turn_off: relay
  - platform: gpio
    pin: GPIO15
    id: relay
    on_turn_on:
      - output.turn_on: led_blue
    on_turn_off:
      - output.turn_off: led_blue

Wireing diagram

FTDI	SP111
3.3v	3.3v
GND	GND
RX	TX
TX	RX
GND	GPIO2

Board layout

My board says SP111 v1.1

Backup current binary from chip

sudo esptool --port /dev/ttyUSB0 --baud 115200 read_flash 0x00000 0x100000 backup.bin

Erasing chip

Was not supported for this particular chip, at least for me. :p

sudo esptool --port /dev/ttyUSB0 --baud 115200 erase_flash

Writing binary to chip

sudo esptool --port /dev/ttyUSB0 --baud 115200 write_flash -fs 1MB -fm dout 0x0 firmware.bin