Tmall Genie Smart USB Switch Teardown

This article is essentially a reverse engineering teardown of a Tmall Genie smart USB switch.

Advantages of the Tmall Genie smart AC switch include voice control, which doesn't require installing any additional apps since the Tmall Genie app allows remote control. However, there are some minor drawbacks, such as the use of a relay in the switch, which is large, power-hungry, and suitable only for AC power situations. Nowadays, many small devices use USB power, such as USB night lights and USB mosquito repellent devices. Therefore, a switch that controls USB power on and off could fill the gap left by the AC switch.

Step 1 Design the schematic:

The schematic isn't complex. The main control chip can be a readily available Bluetooth BLE chip. The program can use the one previously created for the Tmall Genie smart light, as the chip operates on 3.3V while USB provides 5V, and some chargers can fast charge up to 20V. Therefore, a voltage regulator (LDO) capable of handling over 20V is required to stabilize the voltage. A field-effect transistor (MOSFET) is used to control the switch. For ease of control, an N-channel MOSFET is used to control the negative circuit. Two LEDs are added to the circuit to indicate the switch's on/off status, with the LED turning on when the switch is connected.

Step 2 Design the PCB:

The wiring is shown on both sides.

The enclosure is designed based on this size, using PCB to create top and bottom plates.

Step 3 Design the enclosure:

The model name can be chosen freely; here, it's TGS-01 (TGS stands for TmallGenie Switch, and 01 represents the first version).

Step 4 Prototyping:

The components are minimal, so they can be soldered manually using a hot air gun. After soldering, attach copper standoffs to secure the PCB to the cover plates, with a cover plate on each side.

Finally, secure the screws, and the product is complete.

After testing with power, it effectively controls a USB fan and a USB night light without issues.

The widespread use of smart speakers like Tmall Genie and Xiao Ai will undoubtedly accelerate the development of the smart home industry. Before smart speakers became widespread, each smart home design company developed their own products with various apps and custom designs. However, after the spread of smart speakers and the release of relevant protocols, developers now follow the same standard rules, avoiding compatibility issues between products. Additionally, implementing smart interactions within apps has become much simpler.