The Sonoff S26R2 uses an ESP8285 MCU and can be re-programmed to use the Tasmota home control firmware.
Dismantle Socket
- Remove bezel around plug pins; just pulls off
- Remove three small screws (PH1 screwdriver)
- Pull from bottom to open shell; has clip at top edge
Attach Wires for Serial Connection
- Pins are clearly marked on underside of PCB
- Found it easiest to solder three-pin header socket to Vcc/Tx/Rx
- Separate wire to ground pin pad
Flash Tasmota
- DO NOT PLUG INTO MAINS
- Connect USB serial adapter to SONOFF S26 pins. ENSURE adapter is set on 3.3 volts and connect Tx to Rx and vice versa
- Test connection by plugging in USB; LED should flash
- Unplug USB, hold down pushbutton on unit whilst plug USB in, then release button; LED should remain off
- Flash Tasmota
- Either via Tasmota Web Installer (needs Google Chrome) which downloads precompiled release version
- Or by compiling source code in PlatformIO:
- Open Tasmota GitHub download in VSCode; open tasmota/tasmota.ino file
- Compile and flash to the S26 socket (should erase flash first)
- Unsolder temporary programming cables
Configure Tasmota
- If using Web Installer can configure through that
- Or use Web UI via SoftAP:
- Use phone/MacBook to connect WiFi AP “tasmota_XXXXXX-####” where string is derived from the device’s MAC address
- Will open Tasmota configuration page, or if not browse to http://192.168.4.1
- Setup WiFi; select SSID and enter password
- Click Save; device will try to connect to network, and show device’s IP address
- Go to new IP address (note: SoftAP will be shut off)
- Configure Module; select Sonoff S2X (8), press Save
- Configure MQTT;
- host: 192.168.0.21 / 1883
- user/password: homeassistant / [STRONGBOX]
- topic: S26_n; n= number of socket
- full topic: %topic%/%prefix%/
- press Save
- Configure Other:
- Web admin password: [STRONGBOX]
- Device name: ESP-S26-n; n = number of socket
- Friendly name: Socket One (etc)
- Emulation: Hue Bridge
- Press Save
- Record MAC address and allocated IP in Network Configuration file
Add to Alexa Control
- Goto “alexa.amazon.co.uk”, select “Smart Home” -> “Devices“
- At bottom of page press “Discover” button; new device should appear in list
- Select “Smart Home” -> “Groups“, select “Christmas“
- Tick new device in list to add to group
References / Resources
- Sonoff S26R2 Documentation
- Tasmota firmware (GitHub)
- Tasmota main documentation (github.io)
- Tasmota guide for programming S26 Smart Socket
- Video showing how to dismantle S26R1 (YouTube)