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Table of contents
Features:
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Small size laser rangefinder when weight and size are critical
•
Long range measurements up to 100 meters to sense remote objects
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Up to 388 readings per second for fast detection of obstacles
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IP67 enclosure prevents damage from water and dust
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Built-in drivers to make a scanning LiDAR by adding a digital servo
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Encoded laser pulses prevent interference for other lasers
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First and last return signals are available to suit your application
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Power saving mode to save energy when not in use.
LW20 / SF20 LiDAR - Product manual - Revision 7
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© LightWare Optoelectronics (Pty) Ltd, 2018
LW20 / SF20 LiDAR sensor
Product manual
The
compact
LiDAR sensor
for drones,
autonomous vehicles
and robots
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www.lightware.co.za
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Table of Contents
Related Manuals for Lightware SF20
Summary of Contents for Lightware SF20
- Page 1 • First and last return signals are available to suit your application • Power saving mode to save energy when not in use. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za...
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Page 2: Table Of Contents
Figure 12 :: Arrangement of screens in terminal emulation mode ................. Figure 13 :: Connection to a Devantech USB-ISS module ..................... Figure 14 :: The LightWare Terminal application top level window showing the toolbar ............Figure 15 :: Selecting the Devantech I2C-ISS converter .................... - Page 3 Information found in this document is used entirely at the reader’s own risk and whilst every effort has been made to ensure its validity, neither LightWare Optoelectronics (Pty) Ltd nor its representatives make any warranties with respect the accuracy of the information contained herein.
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Page 4: Overview Of The Lw20
388 measurements can be made each second. The data can be streamed from the communication ports or analysed internally to look for potentially hazardous alarm conditions. The LW20 is also available as an open frame module for OEMs using part code SF20. 2. What can the LW20 do? The LW20 can be used as an altimeter on multi-copter drones to measure the exact height above ground level or to set off alarms when the ground gets too close. -
Page 5: What Are The Main Characteristics Of The Lw20
It can easily be added onto existing products. LW20 The SF20 is an open unit suitable for clean and dry applications or as an OEM component that is built-in as standard equipment. The LW20 housing measures 20 mm x 30 mm x 35 mm. - Page 6 For human-to-machine communication there is an internal menu system that can be • accessed using a generic terminal application via the serial port. The LightWare Terminal application can be used for this. For interactive and graphical communication there is a GUI based Terminal application •...
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Page 7: Specifications Of The Lw20 / Sf20
Wire tail, 5 core plus Wire tail, 5 core plus Wire tail, 5 core plus shield shield shield shield IP 67 IP 67 Enclosure rating LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 8: How To Communicate With The Lw20 Using The Graphical Interface
Figure 4 :: Connection to a USB converter cable Once the converter is wired up to the LW20, prepare the Terminal application on the PC as follows: Download and instal the latest Terminal application from the LightWare website • Open the Terminal application •... -
Page 9: Figure 6 :: The Graphical Interface Home Screen
The graphics can be manipulated to alter their position and angle of view using the left and right mouse keys. There is a scale slider in the top right hand corner along with icons to return to the default isometric view or change to a view from above. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 10: Figure 8 :: The Graphical Interface Parameters Screen
LiDAR scanning. Figure 9 :: The graphical interface Operate screen LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 11: How To Communicate With The Lw20 Using A Terminal Emulator
The “?” command mentioned above is the command used to identify the LW20. The full command listing can be found in Appendix C. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 12: Figure 12 :: Arrangement Of Screens In Terminal Emulation Mode
Pressing the <±> or <~> key switches back into machine-to-machine mode. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 13: Figure 13 :: Connection To A Devantech Usb-Iss Module
Figure 14 :: The LightWare Terminal application top level window showing the toolbar Select the correct protocol using the “Settings” icon on the toolbar of the LightWare Terminal. This should match the I2C converter being used and in this example the Devantech USB-ISS adaptor is shown. -
Page 14: Figure 16 :: I2C Test Dialog Box Showing Command Buttons
Figure 16 :: I2C test dialog box showing command buttons The factory default I2C bus address is 0x66. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 15: How To Communicate With The Lw20 Using A Controller
The LW20 is designed to communicate with a host controller. This controller can be a single board computer, flight controller or a PC. There are two communications interfaces available, serial and I2C. The LW20 and SF20 models both ship with a single serial and I2C communication cable. -
Page 16: How To Do An Initial Setup Of The Lw20
115200. I2C address 0x00 … 0x7F The address of the LW20 on the I2C bus, the factory default is 0x66. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 17: How To Set Up A Scanning Lidar Using A Digital Servo
If a new value beyond the capabilities of the servo is entered, the servo may draw too much power, get hot or buzz. CAUTION: Setting PWM values outside the specified range of the servo may cause damage to the servo. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 18: Figure 20 :: Setting The Servo's Limits Of Motion Using The Pwm Values
Once the electrical characteristics of the servo have been entered using the method above, the servo can be used to aim the LW20 in a specific direction or autonomously scan the LW20 to produce LiDAR maps and provide collision warning alarms. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 19: Figure 22 :: Setting Up The Servo's Scanning Characteristics
In most applications, the field of view of the scanning pattern will need to be reduced. This could be because of fixed objects inside the scanning area or to remove errors at the edges of the scan caused by the servo changing direction. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 20: Figure 24 :: Reducing The Field Of View To Avoid Detecting The Landing Legs On A Drone
Switching from bi-directional to uni-direction scans is done using the “Scan type” selection box. Figure 25 :: Uni-directional scanning for higher precision LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 21: How To Set Up The Alarms
The maximum range can be reached on white painted walls that have high reflectivity and a large surface area. Surfaces that are darker in color or smaller in size can only be measured at shorter ranges. LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018... -
Page 22: Instructions For Safe Use
Figure 29 :: Dimension drawings of the LW20 and SF20 Cautionary note Ensure that adequate ventilation or heat sinking is provided if the SF20 is incorporated into a custom enclosure, as heat build-up could occur. LW20 / SF20 LiDAR - Product manual - Revision 7 ©... -
Page 23: Appendix B :: Cables And Connections
LightWare Optoelectronics (Pty) Ltd LA 000_093: LW/SF20 Serial & power cable Rev: 2 Figure 30 :: Serial and power cable Figure 31 :: Pinout diagram LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... -
Page 24: Appendix C :: Complete Command Set For Machine-To-Machine Communications
Signal strength of last return (%) lo:0.14 Read distance measurement datum offset #LO,0.56 lo:0.56 Change to a new datum offset: Adjustment range = -10.00 … 10.00 LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za... - Page 25 Read the us per degree scale of the servo #SWS,10.00 sws:10.00 Change the us per degree scale of the servo: Adjustment range = 0.1 … 1000.0 LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za...
- Page 26 0 = power off 1 = power on Legacy commands for the serial port D’ or ‘d’ 78.32 Output the current distance once only LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za...
- Page 27 LW20 / SF20 LiDAR - Product manual - Revision 7 © LightWare Optoelectronics (Pty) Ltd, 2018...
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Page 28: Revision History
Rev 6 2018/04/05 Updated “4. Specifications of the LW20 / SF20” item “Range” to “0.2 … 100 m (sunlit white wall, 45 readings per second)” (pages 4, 5). “4. Specifications of the LW20 / SF20” item “Beam divergence” to “0.3°” (page 5). Updated “Figure 13 :: Connection to a Devantech USB-ISS module”...