Sonoff Mini R2 Switch flashing Tasmota

I purchased couple of Sonoff Mini R2 Switch modules. They are small and could be installed inside flush-mounted electrical box. I decided to put them in the rooms where I do not want to spent for Sonoff T0 Wall Switch. It is cheaper solution to use with standard wall switches but with the same functionality. Full specs you may find on ITead website.

Original Sonoff Mini R2 Switches works with Ewelink app. But there is also way to flash with Tasmota. So pre-condition is to have firmware version installed >v3.5. Recently even we may purchase pre-flashed modules with firmware in v3.6, and on the box you have information that is for DYI Mode.

There are 3 ways of flashing:

• you can re-assemble case and find pins, then solder and flash as any Sonoff device. Useful tutorial and pinouts find here: https://templates.blakadder.com/sonoff_mini.html
• you may enable DYI mode and then using Windows and Itead app to flash firmware
• you may enable DYI mode and then using Linux or MacOS cli upload tasmota firmware.

I will focus on third option as this is much quicker. Full tutorial you may find on the Tasmota Wiki. I re-used steps with some modifications as some steps were not clear for me.

1. Long press the button for 5 seconds to enter pairing mode, then press another 5 seconds to ender Compatible Pairing Mode (AP). The LED indicator should blink continuously.
2. From mobile phone or PC WiFi setting, an Access Point of the device named ITEAD-XXXXXXXX will be found, connect it with default password 12345678
3. Open the browser and access http://10.10.7.1/
4. Next, Fill in WiFi SSID and password. Once successfully connected, the device is in DIY mode.
5. Locate your device in your network. Write down IP of Sonoff mini.
6. Run curl command to get information about installed version and OTA feature enabled/disabled:

curl -XPOST --header "Content-Type: application/json" --data-raw '{"deviceid": "", "data": {}}' http://SONOFFMINI-IP:8081/zeroconf/info

you should get something like this:

{"seq":2,"error":0,"data":{"switch":"off","startup":"off","pulse":"off","pulseWidth":500,"ssid":"wifi-network","otaUnlock":false,"fwVersion":"3.6.0","deviceid":"100103df7d","bssid":"d8:47:32:4d:c2:2","signalStrength":-60}}

as you see version is 3.6.0 and OTA is disabled in false value. Let’s change it to enable possibility of remote uploading firmware:

curl -XPOST --header "Content-Type: application/json" --data-raw '{"deviceid": "", "data": {}}' http://SONOFFMINI-IP:8081/zeroconf/ota_unlock

you may again sent info query to check if option otaUnlock has been updated:

curl -XPOST --header "Content-Type: application/json" --data-raw '{"deviceid": "", "data": {}}' http://SONOFFMINI-IP:8081/zeroconf/info

{"seq":2,"error":0,"data":{"switch":"off","startup":"off","pulse":"off","pulseWidth":500,"ssid":"wifi-network","otaUnlock":true,"fwVersion":"3.6.0","deviceid":"100103df7d","bssid":"d8:47:32:4d:c2:2","signalStrength":-60}}

Now we may flash with tasmota. NOTE: You have to use version tasmota-lite due to buffer size on Sonoff mini. DO NOT USE tasmota-minimal version! It is not for initial flashing.

Go on the website http://sonoff-ota.aelius.com/ and check for available firmware. You have to copy SHA checksum to provide in next command

To flash please use this:

curl -XPOST --data "{\"deviceid\":\"\",\"data\":{\"downloadUrl\": \"http://sonoff-ota.aelius.com/tasmota-9.3.1-lite.bin\", \"sha256sum\": \"ca5bef633cb972040e3f403322b9cabf157dbc0b7ee64d2ff17a0683ffcafb64\"} }" http://SONOFFMINI-IP:8081/zeroconf/ota_flash

It takes a wile and device should restart with initial tasmota setup.

Further configuration notes. When you configure WIFI and connect to tasmota, the easiest way for configuring is to use tasmota template:

It enables all available options for relay, leds and external button.

If you require to open sonoff mini please find useful pictures:

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If require soldering and flashing you may find useful this:

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