Teardown: SONOFF Smart Switch(Mini2)

Bought this Sonoff Mini2 Smart switch recently. It has one 16A node and external switch can be connected to manual ON/OFF Operation.

The architecture is quite similar to what you will see in any other smart switch.

Teardown: SONOFF Smart Switch(Mini2) 1

AC to DC power supply which converts Main AC 230V to 5V DC and then 5V to 3.3V is converted using a linear regulator.

A Wi-Fi module or Wireless SoC which will act as a main MCU and connectivity interface. On the Top side(bottom – right) antenna is used for Wi-Fi, instead of usual PCB antenna.

External switch is connected on IO pin, one pullup and debouncing caps we can see(R8, C23). Mosfet is used for driving the 5V DC Relay.

You can see some test points by name GND, 3V, T, R. T, R I am assuming as RX and TX of the UART.

Here are the high resolution pics of the inside of Sonoff Smart Switch.

  • Teardown: SONOFF Smart Switch(Mini2) 2
  • Teardown: SONOFF Smart Switch(Mini2) 3
  • Teardown: SONOFF Smart Switch(Mini2) 4
  • Teardown: SONOFF Smart Switch(Mini2) 5

Various ICs used are:

Did you expect something else inside a this Sonoff Smart switch?

If you have any questions please ask in the comments section below, I will try to respond as soon as possible.

You can read other teardown blogs and watch teardown videos.


I am currently working as an embedded systems design consultant and helping companies build custom embedded products, develop test automation solution for their PCB or complete product.

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