1. The TCA9548A adapter is connected to an I2C device with multiple identical addresses on the same I2C port on the main control board for normal communication and use. There are 8 I2C interfaces on one expander, and there are eight bi directional transfer switches that can control the I2C bus. This means that after transferring 1 expander, 8 identical addresses can be connected to the same I2C port. 2. Expansion Card TCA9548A, Compatible with IIC Bus and System Management Bus (SMBus), Active Low Reset Input, Support for Hot Insertion, Low Standby Current, No Interference When Power On, Support for Voltages Between 1.8V, 2.5V, 3.3V and 5V Level Shifting, TCA9548A I2C IIC Multiplexer Breaker. The programmable control register can select any single SCn/SDn channel or a combination of channels. 3. If the 8 channel expansion card device is also used normally, the default address of this expander is 0x70, the address can be changed and set between 0x70 and 0x77 as needed. Theoretically, 8 expanders can be cascaded in the address 0x700x77, and each expander can connect 8 devices with the same address. This realizes the same I2C port and connects 64 devices with the same address and uses them normally. 4. If a timeout or other faulty operation occurs, the system master can reset the TCA9548A, setting the /RESET input to Low. Similarly, a power on reset selects all channels and initializes the I2C/SMBus state machine. Reset and initialization can also be achieved, /RESET is activated, and there is no need to turn off the part.