Abstract: A data transmission system includes a master device and a slave device group. The slave device group includes a first slave device and a second slave device. The master device, the first slave device, and the second slave device are sequentially connected in series along a data transmission path. The master device transmits a streaming signal to the slave device group, and the slave device group analyzes the streaming signal to identify which one of the first slave device and the second slave device is a target slave device for performing an access operation on the streaming signal. The target slave device generates a streaming response signal based on the streaming signal and transmits the streaming response signal to the master device. The master device analyzes the streaming response signal to identify the streaming response signal is generated by the first slave device or the second slave device.

Abstract: Disclosed are a teaching feedback system and a teaching feedback method. The teaching feedback system includes a server and an electronic device, and the server is linked to the electronic device. Data is pre-established in the server and the data is transmitted to the electronic device. After a user selects from the data received by the electronic device, the electronic device generates a demand signal, and transmits the demand signal and the selected data to the server. The server performs an adjustment according to the demand signal and the selected data. In this way, the user's need can be fed back, and a teaching method is adjusted according to individual needs, thereby achieving customization, and providing a better learning effect.

Abstract: Disclosed is a surge protection device, including a power input port connecting a voltage source, a power output port connecting a load, a switching element connecting the power output port, a voltage measurement circuit connecting the power input port, a processing circuit, and a switch control circuit. The voltage measurement circuit generates a voltage measurement signal based on an input voltage signal of the voltage source. When the processing circuit determines that the input voltage signal is in a normal state based on the voltage measurement signal, it controls the switching element to be turned on, to make the voltage source supply power to the load. The switch control circuit compares the voltage measurement signal with a voltage threshold, to control the switching element to be turned off when it determines that the input voltage signal is in a surge state, so that the power output port is powered off.

Abstract: A controller having a wireless transmission interface is provided. The controller includes an amplifier, an analog-to-digital converter, a digital filter, a processor, and a radio frequency signal transceiver. The amplifier is coupled to the wireless transmission interface, and generates an amplification signal according to an input signal. The analog-to-digital converter is coupled to the amplifier, and configured to convert the amplification signal into a digital format. The digital filter is coupled to the analog-to-digital converter, and configured to filter the amplification signal in the digital format to generate a filtered signal. The processor is coupled to the digital filter, and configured to perform a calculation on the filtered signal to generate a calculation result. The radio frequency signal transceiver is coupled to the processor, and obtains received information according to the calculation result and the filtered signal.

Abstract: Disclosed is a radio frequency (RF) front-end chip provided with a first antenna port and including a RF analog front-end module, a filtering module, and a switching module. The RF analog front-end module includes a first transceiver unit transmitting and receiving a signal of a first frequency band, and a second transceiver unit and a third transceiver unit transmitting and receiving a signal of a second frequency band. The filtering module transmits the received signal to the first transceiver unit or the second transceiver unit and the third transceiver unit based on the frequency band of the received signal. The switching module switches the first antenna port to the first transceiver unit, the second transceiver unit, the third transceiver unit or the filtering module, so that the first transceiver unit, the second transceiver unit or the third transceiver unit receives or transmits a signal through the first antenna port.

Abstract: The present disclosure provides an image resolution adjustment system and a method thereof. The system comprises a transmitter and an image display device. The image display device presets a first resolution display screen. A wireless link is established between the image display device and the transmitter. The transmitter transmits a wireless signal. The image display device obtains the wireless signal from the transmitter. The image display device performs a position algorithm according to the wireless signal to calculate a relative position and perform the image adjustment for the first resolution display screen according to the relative position to generate a second resolution display image. So, the screen resolution of the image display device is adjusted according to the relative position such that users can have better visual effect and convenience.

Abstract: The present disclosure provides an indoor direction finding method, which is applied to an indoor direction finding system. The indoor direction finding system comprises a transmitter and a receiver. A Bluetooth communication link is established between the receiver and the transmitter. The indoor direction finding method is performed by the receiver with the steps of: obtaining a receiver coordinate information of the receiver; receiving a Bluetooth signal moving in single direction at the receiver coordinate information; confirming a relative position information of the transmitter according to the receiver coordinate information and the Bluetooth signal moving in single direction. By obtaining the Bluetooth signal moving in single direction, the azimuth of the transmitter can be confirmed for improving the indoor direction finding accuracy.

Abstract: A controller having a wireless transmission interface is provided. The controller includes an amplifier, an analog-to-digital converter, a digital filter, a processor, and a radio frequency signal transceiver. The amplifier is coupled to the wireless transmission interface, and generates an amplification signal according to an input signal. The analog-to-digital converter is coupled to the amplifier, and configured to convert the amplification signal into a digital format. The digital filter is coupled to the analog-to-digital converter, and configured to filter the amplification signal in the digital format to generate a filtered signal. The processor is coupled to the digital filter, and configured to perform a calculation on the filtered signal to generate a calculation result. The radio frequency signal transceiver is coupled to the processor, and obtains received information according to the calculation result and the filtered signal.