Add Teckin SP20 (US) example to 'Generic Sonoff' page (#191)

* add Teckin SP20 (US) example to 'Generic Sonoff' page

* Simplify config

devices/sonoff.rst

@@ -327,6 +327,23 @@ Teckin
 See :doc:`/components/sensor/hlw8012` for measuring power.
 Example config: `teckin.yaml <https://github.com/esphome/esphome-docs/blob/current/devices/teckin.yaml>`__
 
+Teckin SP20 (US)
+----------------
+
+.. pintable::
+
+    GPIO13, Button,
+    GPIO2, Blue LED (inverted),
+    GPIO0, Red LED (inverted),
+    GPIO4, Relay,
+
+    GPIO12, HLW8012 SEL Pin (inverted),
+    GPIO5, HLW8012 CF Pin,
+    GPIO14, HLW8012 CF1 Pin,
+
+See :doc:`/components/sensor/hlw8012` for measuring power.
+Example config: `teckin_sp20_us.yaml <https://github.com/esphome/esphome-docs/blob/current/devices/teckin_sp20_us.yaml>`__
+
 See Also
 --------
 

devices/teckin_sp20_us.yaml

@@ -0,0 +1,93 @@
+# Example ESPHome code to emulate stock firmware functionality while maintaining 100% 
+# local control through Home Assistant.
+
+substitutions:
+  device_name: '<NODE_NAME>'     # used internally.. e.g. teckin_sp20
+  friendly_name: '<Node Name>'   # displayed in HA.. e.g. Teckin SP20
+  wifi_ssid: '<WIFI_SSID>'
+  wifi_password: '<WIFI_PASSWORD>'
+
+esphome:
+  name: ${device_name}
+  platform: ESP8266
+  board: esp01_1m
+
+wifi:
+  ssid: ${wifi_ssid}
+  password: ${wifi_password}
+
+# Enable Logs from the device
+logger:
+
+# Enable Home Assistant API
+api:
+
+# Enable Over-The-Air updates
+ota:
+
+sensor:
+  # Power measuring sensor
+  - platform: hlw8012
+    sel_pin:
+      number: GPIO12
+      inverted: True
+    cf_pin: GPIO5
+    cf1_pin: GPIO14
+    current:
+      name: ${friendly_name} Current
+    power:
+      name: ${friendly_name} Power
+      id: power
+      filters:
+        # Some calibration
+        - multiply: 0.4545
+    voltage:
+      name: ${friendly_name} Voltage
+    current_resistor: 0.001  # default 0.001
+    voltage_divider: 910     # default 2351
+    change_mode_every: 3     # default 8
+    update_interval: 3s      # default 60s
+
+  # Sum power readings over the day
+  - platform: total_daily_energy
+    name: ${friendly_name} Total Daily Energy
+    power_id: power
+    filters:
+      - multiply: 0.001   # convert Wh to kWh
+    unit_of_measurement: kWh
+
+# Enable getting local time for total daily energy calculation
+time:
+  - platform: homeassistant
+    id: homeassistant_time
+
+status_led:
+  pin:
+    number: GPIO0   # Red LED
+    inverted: True
+
+binary_sensor:
+  - platform: gpio
+    pin: GPIO13
+    id: button
+    name: ${friendly_name} Button
+    on_press:
+      - switch.toggle: relay
+    internal: True
+
+switch:
+  - platform: gpio
+    id: blue_led
+    pin:
+      number: GPIO2
+      inverted: True
+    
+  - platform: gpio
+    pin: GPIO4
+    id: relay
+    name: ${friendly_name}
+    # Tie Blue LED to relay
+    on_turn_on:
+    - switch.turn_on: blue_led
+    on_turn_off:
+    - switch.turn_off: blue_led