Abstract: A first device is logged in with a first user account. The first device displays an avatar of a second user account in a first user interface of the first device. In response to an interaction instruction triggered on the avatar of the second user account, the first device generates an interaction message according to a first field corresponding to the first user account, an action description field corresponding to the interaction instruction, and a second field corresponding to the second user account. The first device transmits the interaction message to a second device that is logged in with the second user account.

Abstract: A first device is logged in with a first user account. The first device displays an avatar of a second user account in a first user interface of the first device. In response to an interaction instruction triggered on the avatar of the second user account, the first device generates an interaction message according to a first field corresponding to the first user account, an action description field used for indicating an action performed by the first user account on the second user account, and a second field corresponding to the second user account. The first device transmits the interaction message to a second device that is logged in with the second user account.

Abstract: A first device is logged in with a first user account. The first device displays an avatar of a second user account in a first user interface of the first device. In response to an interaction instruction triggered on the avatar of the second user account, the first device generates an interaction message according to a first field corresponding to the first user account, an action description field used for indicating an action performed by the first user account on the second user account, and a second field corresponding to the second user account. The first device transmits the interaction message to a second device that is logged in with the second user account.

Abstract: A message transmitting method and apparatus provide for a subtle reminder function. Head portraits of at least two user accounts are displayed in a first chat interface. The at least two user accounts include a first user account and a second user account. An interaction message is generated in response to an interaction with the head portrait of the second user account. The interaction message is transmitted to the second user account. The interaction message is used to trigger the display of an animation of the head portrait of the second user account in a second chat interface. This provides for a new interaction between user accounts, and can provide a subtle reminder function.

Abstract: An ultrasonic sensing system includes a comparator, an analog-to-digital converter (ADC) coupled to the comparator, and a processor coupled to the comparator and the ADC. The comparator is configured to compare an input signal with a triggering value and trigger proximity measurement in response to an amplitude of the input signal being greater than the triggering value. The ADC is configured to convert the input signal to a digital signal. The processor is configured to, in response to the proximity measurement being triggered, determine a peak time point when a peak amplitude is received based on the digital signal and calculate a distance based on the peak time point. The peak time point is different from a time point when the proximity measurement is triggered.

Abstract: A method and a device for measuring flight parameters of an unmanned aerial vehicle (UAV) are provided, the method includes, capturing images and collecting an angular velocity of the UAC, extracting corner points from a current frame image, estimating an estimated area according to the angular velocity of the UAV, searching for a corresponding corner point in the estimated area, obtaining a speed of each of the corner points, obtaining a pixel velocity, and obtaining an actual speed of the UAV based on the pixel velocity and a flight altitude of the UAV.

Abstract: An ultrasonic sensing system includes an ultrasonic receiver configured to receive an ultrasonic signal and a gain-adjustable amplifier operably coupled to the ultrasonic receiver. The gain-adjustable amplifier is configured to amplify the ultrasonic signal according to a variable gain determined based at least in part on a value of a timer that corresponds to a measuring distance.

Abstract: A method for communicating ground terminal-to-unmanned aerial vehicle (GT-UAV) data one or more times to an unmanned aerial vehicle (UAV) from a ground terminal includes receiving the GT-UAV data over a wireless channel, transmitting UAV image data to the ground terminal over the wireless channel, determining whether the received GT-UAV data is transmitted according to an Acknowledgment (ACK) protocol, and transmitting an acknowledgment signal over the wireless channel to the ground terminal in response to the received GT-UAV data being determined to be transmitted according to the ACK protocol.

Abstract: A method and a device for measuring flight parameters of an unmanned aerial vehicle (UAV) are provided, the method includes, capturing images and collecting an angular velocity of the UAC, extracting corner points from a current frame image, estimating an estimated area according to the angular velocity of the UAV, searching for a corresponding corner point in the estimated area, obtaining a speed of each of the corner points, obtaining a pixel velocity, and obtaining an actual speed of the UAV based on the pixel velocity and a flight altitude of the UAV.

Abstract: A method and a device for measuring flight parameters of an unmanned aerial vehicle (UAV) are provided, the method includes, capturing images and collecting an angular velocity of the UAC, extracting corner points from a current frame image, estimating an estimated area according to the angular velocity of the UAV, searching for a corresponding corner point in the estimated area, obtaining a speed of each of the corner points, obtaining a pixel velocity, and obtaining an actual speed of the UAV based on the pixel velocity and a flight altitude of the UAV.

Abstract: A wireless transmission protocol for exchanging data between an unmanned aerial vehicle and a ground terminal is provided. The unmanned aerial vehicle is configured to transit image or video media data while mid-flight. The unmanned aerial vehicle and the ground terminal share a single communications channel using a time division multiple data access protocol. The unmanned aerial vehicle and the ground terminal use different communication protocols to send different types of data signals.

Abstract: An ultrasonic sensing system includes an ultrasonic receiver configured to receive an ultrasonic signal and a gain-adjustable amplifier operably coupled to the ultrasonic receiver. The gain-adjustable amplifier is configured to amplify the ultrasonic signal according to a variable gain determined based at least in part on a value of a timer that corresponds to a measuring distance.

Abstract: Methods, systems and device are provided for improving the range and accuracy of proximity measurement such as in ultrasonic sensing systems. In particular, the blind zone caused by reverberation signals can be reduced or eliminated by attenuating signals received during the time period corresponding to the blind zone without. In an implementation, an attenuator circuit is selected by a switch to process received signals during the blind zone time period and deselected by the switch after the time zone time period. Additionally, the accuracy and range of the measurement can be improved by varying the gain provided to the received signals based on the varying measuring distance. In an implementation, a gain-adjustable amplifier is controlled by a gain control signal to provide incremental gain as time increases.

Abstract: A wireless transmission protocol for exchanging data between an unmanned aerial vehicle and a ground terminal is provided. The unmanned aerial vehicle is configured to transit image or video media data while mid-flight. The unmanned aerial vehicle and the ground terminal share a single communications channel using a time division multiple data access protocol. The unmanned aerial vehicle and the ground terminal use different communication protocols to send different types of data signals.

Abstract: A method and a device for measuring flight parameters of an unmanned aerial vehicle (UAV) are provided, the method includes, capturing images and collecting an angular velocity of the UAC, extracting corner points from a current frame image, estimating an estimated area according to the angular velocity of the UAV, searching for a corresponding corner point in the estimated area, obtaining a speed of each of the corner points, obtaining a pixel velocity, and obtaining an actual speed of the UAV based on the pixel velocity and a flight altitude of the UAV.

Abstract: Methods, systems and device are provided for improving the range and accuracy of proximity measurement such as in ultrasonic sensing systems. In particular, the blind zone caused by reverberation signals can be reduced or eliminated by attenuating signals received during the time period corresponding to the blind zone without. In an implementation, an attenuator circuit is selected by a switch to process received signals during the blind zone time period and deselected by the switch after the time zone time period. Additionally, the accuracy and range of the measurement can be improved by varying the gain provided to the received signals based on the varying measuring distance. In an implementation, a gain-adjustable amplifier is controlled by a gain control signal to provide incremental gain as time increases.

Abstract: Methods, systems and device are provided for improving the range and accuracy of proximity measurement such as in ultrasonic sensing systems. In particular, the blind zone caused by reverberation signals can be reduced or eliminated by attenuating signals received during the time period corresponding to the blind zone without. In an implementation, an attenuator circuit is selected by a switch to process received signals during the blind zone time period and deselected by the switch after the time zone time period. Additionally, the accuracy and range of the measurement can be improved by varying the gain provided to the received signals based on the varying measuring distance. In an implementation, a gain-adjustable amplifier is controlled by a gain control signal to provide incremental gain as time increases.

Abstract: Methods, systems and device are provided for improving the range and accuracy of proximity measurement such as in ultrasonic sensing systems. In particular, the blind zone caused by reverberation signals can be reduced or eliminated by attenuating signals received during the time period corresponding to the blind zone without. In an implementation, an attenuator circuit is selected by a switch to process received signals during the blind zone time period and deselected by the switch after the time zone time period. Additionally, the accuracy and range of the measurement can be improved by varying the gain provided to the received signals based on the varying measuring distance. In an implementation, a gain-adjustable amplifier is controlled by a gain control signal to provide incremental gain as time increases.