Shelly Dimmer 2 Dimmer Module
Shelly Dimmer 2

Available from:


Install method:
MgOS to Tasmota

GPIO #Component
GPIO00 None
GPIO01 Serial Tx
GPIO02 None
GPIO03 Serial Rx
GPIO04 SHD Boot 0
GPIO05 SHD Reset
GPIO09 None
GPIO10 None
GPIO12 Switch_n 2
GPIO13 None
GPIO14 Switch_n 1
GPIO15 None
GPIO16 Led_i 1
{"NAME":"Shelly Dimmer 2","GPIO":[0,3200,0,3232,5568,5600,0,0,193,0,192,0,320,4736],"FLAG":0,"BASE":18}

Supported since Tasmota 9.2+

After flashing Tasmota, apply the template and then use the Firmware upgrade - File upload menu to flash the required STM32 firmware (provided at shelly-dimmer-stm32 releases page) to the MCU. The template must be set before flashing the STM32 firmware. Note that you may have to load the STM32 firmware a second time before it works.

After the firmware upgrade for the STM32 firmware you should execute some commands:

  1. switchmode 11 -> pushbutton with dimmer mode
  2. use “SetOption32” to set the time for dim up/down start (10 = 1 sec)
  3. If you want to use the dimmer with one button mode, you can check here: https://tasmota.github.io/docs/Rules/#control-a-dimmer-with-one-switch (be sure to change the MQTT topics to the right ones your device is using)
  4. Ledtable 0 -> Disable gamma control
  5. ShdLeadingEdge -> set to 0 for trailing edge and 1 to leading edge. Be careful to set the right type for your load!
  6. Exceute “Dimmer 1” and then use the “DimmerRange” command beginning counting from 0 upwards (DimmerRange 0, DimmerRange 1 and so on), until you see your light start dimming.
  7. If you have flickering at low light levels, try the new ShdWarmupBrightness command (see https://github.com/jamesturton/shelly-dimmer-stm32/pull/23 ). Use only with LED and at your own risk!

You can try to revert back to the stock firmware using OTA with this tool if you have any issues: https://github.com/yaourdt/tasmota-to-mgos If this fails you have to use the serial connection. If you reverted back to the original Shelly firmware the STM32 should be flashed back automatically to the originally Shelly version.