The new Sonoff DualR3 is here!

We got a nice little surprise in the mail today. The all new Sonoff DualR3, a Dual Relay Wi-Fi Smart Switch with Power Metering. With this ESP ‘thing’  you can operate (2) lights, appliances and motorized facilities like blinds and shutters. According to Sonoff it’s the first smart switch with TUV certification and a high-level of quality and reliability.

On the box it say’s it’s a DIY DUALR3, 2-gang WIFI smart switch. When opening up we found there actually is a ESP32 inside. That explains the ‘Bluetooth pairing’ option, which is mentioned on the Sonoff website. We found there are no headers on the board for easy external programming of the ESP, so let’s just hope the ‘DIY’ here means this board has the DIY architecture which allows Over The Air (OTA) flashing of the boards firmware.  We tested this, but after putting the Dual R3 in AP mode, it get’s 192.168.1.1 and not the familiar 10.10.7.1 IP-Address. Visiting 192.168.1.1 from the browser just outputs some useless JSON data string 🙁

Bluetooth pairing using the EWlink software works like a charm, no complaints there but surely the device would become much more interesting to us Home Automation nerds if we could flash Tasmota or Esphome firmware. 😛

So we hacked our way into this ‘thing’ and soldered some wires to the tiny TX-RX, GND and 3V3 solder pads on the board. After that we hooked up a UART interface and pressed the Sonoff’s button while booting… et voila!

We put a default esp32 esphome config in it with just wifi, captive portal, api, OTA and logger modules active and booted the ‘thing’:

INFO Starting log output from sonoff_dualr3.local using esphome API
INFO Connecting to sonoff_dualr3.local:6053 (192.168.207.226)
INFO Successfully connected to sonoff_dualr3.local
[17:58:45][I][app:105]: ESPHome version 1.16.2 compiled on Mar  4 2021, 17:40:36
[17:58:45][C][wifi:443]: WiFi:
[17:58:45][C][wifi:303]:   SSID: [redacted]
[17:58:45][C][wifi:304]:   IP Address: 192.168.207.226
[17:58:45][C][wifi:306]:   BSSID: [redacted]
[17:58:45][C][wifi:307]:   Hostname: 'sonoff_dualr3'
[17:58:45][C][wifi:311]:   Signal strength: -68 dB ▂▄▆█
[17:58:45][C][wifi:315]:   Channel: 1
[17:58:45][C][wifi:316]:   Subnet: 255.255.255.0
[17:58:45][C][wifi:317]:   Gateway: 192.168.207.1
[17:58:45][C][wifi:318]:   DNS1: 192.168.207.101
[17:58:45][C][wifi:319]:   DNS2: 0.0.0.0
[17:58:46][C][logger:185]: Logger:
[17:58:46][C][logger:186]:   Level: DEBUG
[17:58:46][C][logger:187]:   Log Baud Rate: 115200
[17:58:46][C][logger:188]:   Hardware UART: UART0
[17:58:46][C][captive_portal:169]: Captive Portal:
[17:58:46][C][web_server:132]: Web Server:
[17:58:46][C][web_server:133]:   Address: sonoff_dualr3.local:80
[17:58:46][C][ota:029]: Over-The-Air Updates:
[17:58:46][C][ota:030]:   Address: sonoff_dualr3.local:3232
[17:58:46][C][ota:032]:   Using Password.
[17:58:46][C][api:095]: API Server:
[17:58:46][C][api:096]:   Address: sonoff_dualr3.local:6053
[17:58:46][C][wifi_signal.sensor:009]: WiFi Signal 'WiFi Signal Sonoff DualR3'
[17:58:46][C][wifi_signal.sensor:009]:   Unit of Measurement: 'dB'
[17:58:46][C][wifi_signal.sensor:009]:   Accuracy Decimals: 0
[17:58:46][C][wifi_signal.sensor:009]:   Icon: 'mdi:wifi'

After some tracing and trying we found the GPIO’s for the LED. Button, Relays and Switches.

esphome yaml:

substitutions:
  devicename: sonoff-dualr3
  long_devicename: Sonoff DualR3

esphome:
  name: $devicename
  platform: ESP32 
  board: esp32dev

wifi:
  ssid: !secret esphome_wifi_ssid
  password: !secret esphome_wifi_password
  power_save_mode: light
  ap:
    ssid: $devicename
    password: !secret esphome_ap_password

captive_portal:
  
api:
  password: !secret esphome_api_password

ota:
  password: !secret esphome_ota_password

web_server:
  port: 80

logger:
  baud_rate: 0

# remove # below to enable ble tracking
#esp32_ble_tracker:

uart:
  tx_pin: GPIO25
  rx_pin: GPIO26
  baud_rate: 38400
  parity: EVEN
  stop_bits: 1
  
sensor:
  - platform: wifi_signal
    name: "$long_devicename WiFi Signal"
    update_interval: 60s
  - platform: cse7761
    update_interval: 5s
    voltage:
      name: "$long_devicename Voltage"
    current_1:
      name: "$long_devicename Current 1"
    current_2:
      name: "$long_devicename Current 2"
    active_power_1:
      name: "$long_devicename Power 1"
    active_power_2:
      name: "$long_devicename Power 2"

output:
  - platform: gpio
    pin: GPIO27
    id: relay1
  - platform: gpio
    pin: GPIO14
    id: relay2

switch:
  - platform: output
    name: "$long_devicename - relay 1"
    output: relay1
    id: sw1
  - platform: output
    name: "$long_devicename - relay 2"
    output: relay2
    id: sw2

status_led:
  pin:
    number: GPIO13
    inverted: yes

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO0
      mode: INPUT_PULLUP
      inverted: True
    name: "$long_devicename button"
    on_press:
      - logger.log: "$long_devicename button"
      - switch.toggle: sw1
  - platform: gpio
    pin:
      number: GPIO32
      mode: INPUT_PULLUP
      inverted: True
    name: "$long_devicename switch 1"
    on_press:
      - logger.log: "$long_devicename switch 1"
      - switch.toggle: sw1
  - platform: gpio
    pin:
      number: GPIO33
      mode: INPUT_PULLUP
      inverted: True
    name: "$long_devicename switch 2"
    on_press:
      - logger.log: "$long_devicename switch 2"
      - switch.toggle: sw2

Ble tracking also works:

[21:08:41][D][esp32_ble_tracker:544]: Found device 54:D2:72:XX:XX:XX RSSI=-89
[21:08:41][D][esp32_ble_tracker:565]:   Address Type: PUBLIC
[21:08:41][D][esp32_ble_tracker:567]:   Name: 'Nuki_XXXXXXXX' [redacted]

 Some more pics: