Reference

Working Principle

TOF is an absolute distance detection technique in which the sensor emits a debugged near-infrared light, which is reflected after an object, and the sensor converts the distance of the subject by calculating the time difference or phase difference of light emission and reflection to generate depth information. Compared with the binocular scheme and the 3D structural light scheme, TOF has the advantages of working distance, wide application scene, and higher accuracy over long distance. Therefore, it is often used in personnel proximity detection, robot barrier avoidance, camera autofocus and other occasions. In the outdoor environment, there is near-infrared light from the sun's light, which affects the measurement of the module.

Communication Specifications

Interfaces and Baut Rate

The TOF Sense standard version supports both UART and CAN communication methods, which share a single interface. The factory default is UART communication, if you need to use CAN communication mode, you can configurate it via the module host computer.

UART Communication

Under serial communication, the Baud rate setting range is shown below.

CAN Communication

Under CAN communication, the Baud rate setting range is shown below.

Module protocol resolution

The protocol consists of Frame Header, Function Mark, Data, sum Check. Among them, Frame Header and Function Mark are fixed values. Data is the data of transfer content. Sum Check is the lowest byte of the sum (that is, all the following bytes added) of Frame Header, Function Mark, and Data.
The composition of the agreement: Frame Header + Function Mark + Data + Sum Check

Example

This example takes a single-module continuous ranging with the UART active output mode as the scenario.

Raw data: 57 00 ff 00 9e 8f 00 00 ad 08 00 00 03 00 ff 3a

The instruction format is as follows:

Cascade ranging measurement

The ranging information for all sensors can be read through a single communication interface by configuring multiple sensors with different IDs and in series. The connection diagram is shown in the following image.

Please note that cascade range is only suitable for UART queries, CAN queries, and CAN active output.

Functional Features

Measurement Modes

TOFSense supports short, medium and long distance measurement modes, each of which can output information such as distance measurement dis, distance status dis status, signal strength signal strength, etc.

Output Methods

TOFSense supports active output, query output.

• The active output is the module's autonomous continuous transmission of measurement data frames, the send frequency is 10Hz.
• The query output is the module receives the query frame and output measurement data frame.

Connection Compatibility

TOFSense supports UART and CAN outputs. These two output methods share the same set of physical interfaces.

• The UART output supports the active output, the query output, and the query output under multiple cascading connections of a single module.
• The CAN output supports the active output, query output, and the active output and query output under multiple module cascading connections.

Data Status Interpretation

Distance Status

The module can output the current distance state, and the user can process the data in conjunction with the distance state, as shown in the table below.

Signal Strength

Indicates the strength of the current return signal, and a higher value indicates that the returned signal is stronger.

FOV

The size of the field of view angle determines the field of view of TOFSense, and the module can change the X-way field-of-view angle fov.x, the Y-direction field angle fov.y, the X-directional offset fov.x_offset, and the Y-direction offset fov.y_offset.

• X, Y direction field of view angle setting range is 15° to 27°
• X, Y direction field of view angle offset setting range is -6° to 6°

Indicator Light

The indicate lights have two flashing states, flashing 50ms quickly and 100ms flashing slowly. The status and meaning of the LED are shown in the table below.