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Benewake Tfmini Datasheet

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Version: A00 Document No.

: SJ-GU-TFmini-01 Page 1 of 10

TFmini Infrared Module Specification

Benewake (Beijing) Co. Ltd.

www.benewake.com

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 2 of 10

Preface

Dear users:

Hello! Thank you for choosing the products from Benewake (Beijing) Co. Ltd.

The manual is prepared to help you to use correctly our company’s products. Before you install and use this
product in the first time, please be sure to carefully read the information attached with the product, which will
help you to use the product better. If you have read this manual fully, we recommend that you keep this manual
in a safe position for future use.

For any other problem occurred during use, please contact our technical supports or after-sales services; we
will try our efforts to help you solve any problem on product use. For any suggestions or comments on the
product use, please submit your feedback to us on the community of our official website (www.benewake.com),
we will focus on each user recommendations.

This is Benewake (Beijing) Co. Ltd.; we are committed to producing the best “Robotic Eyes” in the world,
and we adhere to the “Customer Experience Based” concept.

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 3 of 10

Table of Contents
1. Main Product Characteristics 4
2. Optical Principle 4
3. Electrical Characteristics 5
4. Optical Characteristics 5
5. Measurement Range and Acceptance Angle 5
6. Serial Port Data Communication Protocol and Line Sequence 7

6.1 Standard Data Format of Serial Port 7

6.2 Line sequence description 8

7. Interface Description of Serial Port Upper Computer 8


8. Product Size Specifications 9
9. Application Notice 10

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 4 of 10

1. Main Product Characteristics


This product is based on ToF (Time of Flight) principle and integrated with unique optical and electrical
designs, so as to achieve stable, precise, high sensitivity and high-speed distance detection.

Product Name TFmini

Operating range 0.3m-12m

Maximum operating range


5m
at 10% reflectivity

Average power consumption 0.12W

Applicable voltage range 4.5V-6V

Acceptance angle 2.3°

Minimum resolution ratio 5mm

Test frequency 100Hz

Test accuracy 1% (less than 6m), 2% (6m-12m)

Distance detection unit mm

Operating center wavelength 850nm

Size 42mm×15mm×16mm

Operating temperature -20℃-60℃

Anti-ambient light 70,000lux

Weight 6.1g

Communication interface UART

Drone altitude holding and terrain following


Main applications Machine control and safety sensor
Robot distance detection

Table 1 Product characteristics and applications


2. Optical Principle
ToF is the abbreviation of Time of Flight technology, and its operating principle is as follows: a modulated near-
infrared light is sent from the sensor and reflected by an object; the distance to the object to be shot can be

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 5 of 10

converted with the sensor by calculating the time difference or phase difference between the light sending and
the light reflection, so as to produce the depth information.

Fig. 1 TF_mini optical simulation of the optical path


3. Electrical Characteristics

Item Symbol Typical value Unit

Input voltage DC 5 V

Average power P ≤120 mW

LED peak current Imax 800 mA

Serial port TTL


VTTL 3.3 V
voltage level

Table 2 TF_mini electrical characteristics


4. Optical Characteristics

Parameter Symbol Condition or description Typical value Unit

Signal acceptance
β 2.3 Degree
angle

Minimum object size that can be


Resolving power De 20 mm
detected at the distance of 2m

Resolution ratio Re Sensitivity to distance change 5 mm

Operating center
λ 850 nm
wavelength

Table 3 Optical characteristics


5. Measurement Range and Acceptance Angle
TF_mini measurement range
Indoor conditions:
The object to be detected has 90% reflectivity and the effective detection distance is 12m;

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 6 of 10

The object to be detected has 10% reflectivity and the effective detection distance is 5m;
Outside conditions:
Under the general sunshine condition (with illumination of lower than 70klux), the effective detection
distance is 7m;
Under the high sunshine condition in summer (with illumination of above 100klux) or the condition with
outdoor black background board, the effective detection distance is 3m.
Note: All distance parameters are set under the opposite direction with the object to be detected.

Fig. 2 Measurement range schematic diagram


TF_mini acceptance angle
The product has an acceptance angle of 2.3˚, which determines the side lengths of different detection ranges of
LiDAR (the detection range is similar to a square shape).

Fig. 3 Detection range (acceptance angle) schematic diagram

Distance/m 1 2 3 4 5 6

Detection
range side 40 80 120 160 200 240
length/mm

Table 4 Relationship between detection range and distance


Description: The distance in the table represents the vertical length between the detection object and the sensor,
expressed in meters; the side length of detection range is expressed in millimeters. In general, only if the side
length of the object to be detected is more than the detection range side length, the output data from LiDAR can
be trusted; if the side length of the object to be detected is less than the detection range side length, the output
data of LiDAR may be fluctuated and the error may be increased.

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 7 of 10

Note: The detection range side length is not equal to the object resolution ratio at the corresponding distance.
6. Serial Port Data Communication Protocol and Line Sequence
The following section describes the connections and communications between TF_mini and external devices,
including the encoding format of the sending data, the communication protocol between the module and the
external devices, the hardware line connection indications, and the related precautions.

Communication protocol UART

Baud rate 115200

Data bit 8

Stop bit 1

Parity bit 0

Table 5 External communications

1 6.1 Standard Data Format of Serial Port


The module data is a hexadecimal output data; each frame data is encoded with 9 bytes, including 1 distance
data (Dist); each distance data has corresponding signal strength information (Strength); the frame end is the
data parity bit.

Byte1-2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8 Byte9

Strength_ Strength_ CheckSum_


0x59 59 Dist_L Dist_H Reserved Raw.Qual
L H L

Data encoding interpretation

Byte1 0x59, frame header, all frames are the same

Byte2 0x59, frame header, all frames are the same

Dist_L distance value is a low 8-bit. Note: The distance value is a hexadecimal value, for
Byte3
example, Distance 1,000cm = 03 E8 (HEX)

Byte4 Dist_H distance value is a high 8-bit.

Byte5 Strength_L is a low 8-bit.

Byte6 Strength_H is a high 8-bit.

Byte7 Reserved bytes.

Byte8 Original signal quality degree.

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 8 of 10

Checksum parity bit is a low 8-bit, Checksum = Byte1 + Byte2 + ... + Byte8, Checksum is
Byte9
the sum of the first 8 bytes of actual data; here is only a low 8-bit.

Table 6 Data encoding format and detailed description

2 6.2 Line sequence description

Fig. 4 TF_mini line sequence description


TFmini line sequence is shown in “TF_mini line sequence description” in Fig. 4; generally, there are provided
with the wiring terminals, among which, the green line corresponds to TX, the white line corresponds to RX, the
red line corresponds to +5V, and the black line corresponds to GND.
7. Interface Description of Serial Port Upper Computer
The upper computer is currently supported with the windows system and applied for TF series of products
output from Benewake (Beijing) Co. Ltd. in accordance with the serial communication protocol; the specific
operations are detailed as below.

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 9 of 10

Fig. 5 Client Interface of Distance Measurement Demonstration in Windows


① Serial transmission port and baud rate selections: Plug in TTL-USB adapter plate, select the
corresponding port number and baud rate, and click the “CONNECT” button to establish the
connection;
② Mode selection: It is the special mode specified for Pix version of TF01 and TF02 products, which is
not provided on TF_mini;
③ Pause button: Click it to pause the upper computer for analysis on the images in ⑧; “AMB” is used for
the internal debugging under special cases and cannot be set in any case;
④ Measurement range area selection: Click 5m or 20m, the range scale in area ⑨ will be adjusted to the
corresponding value.
⑤ Data average: The default value is 5; that is, the values of every 5 points accepted by the upper
computer are averaged and output at a point value. After modified, the command will be sent with
“Enter” key on the keyboard;
⑥ Serial port command sending area: This window is used to send hexadecimal TF serial port command
and modify or set the function;
⑦ Data recording bar. This text window is used to name the data to be saved; after the name is input, press
“Enter” key to record TF data by clicking “RECORD” button and end the record by clicking the button
again; the folder with saved data can be opened by clicking “FOLDER” button;
⑧ Data image display area: the upper computer can draw a continuous ranging image with the received
data;
⑨ Measurement range scale: Display the real-time detection distance value;
⑩ Data display area: Dist indicates the distance detection value in mm; EffectivePoint indicates the total
effective data output by TF; Strength indicates the signal strength, under the pix mode, Strength is
defaulted as 0 because there is no strength input.
8. Product Size Specifications
The following is the module outline size drawing.

Benewake (Beijing) Co. Ltd.


Version: A00 Document No.: SJ-GU-TFmini-01 Page 10 of 10

Fig. 6 TF_mini left module size drawing (unit: mm)


9. Application Notice
 This product is a custom precision optical instrument and must be maintained by our engineers.
 Prevent dust or any other foreign matter from entering the lens; otherwise it may affect the light
transmission.

Benewake (Beijing) Co. Ltd.

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