Lightware SF40/C User manual

SF40/C
Product manual
SF40/C
Product manual
SF40/C -Product manual | 1 of 30 | © LightWare Optoelectronics (Pty) Ltd, 2019 | www.lightware.co.za
LiDAR SENSOR
IJsselburcht 26
NL - 6825 BP Arnhem
Nederland
Tel. [phone]
[e-mail]
KVK 70937338

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Table of contents
Table of contents
1. About this document
1.1. Product support
1.2. Revision history
1.3. Disclaimer
2. Firmware change log
2.1. Upgrading
2.2. 1.4.0
2.3. 1.3.0
2.4. 1.2.0
2.5. 1.1.2
2.6. 1.1.1
2.7. 1.1.0
2.8. 1.0.1
3. Safety instructions
3.1. Overview
3.2. Labeling
3.3. Laser radiation information
4. Specications
5. Functional description
5.1. Overview
5.2. Data streaming
5.3. Alarms
5.4. Virtual laser range nder
6. Hardware
6.1. Connector wiring
6.2. Mounting on an airframe
6.3. Dimension drawings
6.4. Labeling
7. Serial interface
7.1. Overview
7.2. Packets
7.3. Checksum
7.4. Receiving packets
7.5. Handling request & response
8. Command list
9. Detailed command descriptions
9.1. Product name [0]
9.2. Hardware version [1]
9.3. Firmware version [2]
9.4. Serial number [3]
9.5. UTF8 textmessage [7]
9.6. User data [9]
9.7. Token [10]
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9.8. Save parameters [12]
9.9. Reset [14]
9.10. Stage rmware [16]
9.11. Commit firmware [17]
9.12. Incoming voltage [20]
9.13. Stream [30]
9.14. Distance output[48]
9.15. Laser ring [50]
9.16. Temperature [55]
9.17. Baud rate [90]
9.18. Distance [105]
9.19. Motor state [106]
9.20. Motor voltage [107]
9.21. Output rate [108]
9.22. Forward oset [109]
9.23. Revolutions [110]
9.24. Alarm state [111]
9.25. Alarm 1 [112]
9.26. Alarm 2 [113]
9.27. Alarm 3 [114]
9.28. Alarm 4 [115]
9.29. Alarm 5 [116]
9.30. Alarm 6 [117]
9.31. Alarm 7 [118]
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1. About this document
1.1. Product support
This document supports the followingdevices (See Firmware change log for rmware details):
Product Hardware Firmware Supported
SF40/C 1 1.4.0 Yes
SF40/C 1 1.3.0 Yes
SF40/C 1 1.2.0 Yes
SF40/C 1 1.1.2 Yes
SF40/C 1 1.1.1 Yes
SF40/C 1 1.1.0 Yes
SF40/C 1 1.0.1 No
1.2. Revision history
Revision Date Notes
6 04/02/2019 Updated dimension drawing.
5 23/01/2019 Added change log for version V1.4.0. Updated link to Upgrader tool.
4 08/11/2018 Added change log for version V1.3.0. Updated link to Upgrader tool. Modied
command Di st ance [ 105] .
3 02/10/2018 Added change log for version V1.1.2 & V1.2.0. Updated link to Upgrader tool.
2 27/09/2018 Added change log for version V1.1.1. Command Di st ance [ 105] now shows the
correct read/writebyte count.
1 26/09/2018
Added change log for version V1.1.0. Added link/descriptionfor Upgrader tool.
Modified command Di st ance [ 105] . UpdatedFDA approval.Updated range and
height specications.
0 4/09/2018 Initial pre-release draft.
1.3. Disclaimer
Informationfound in this document is used entirely at the readerʼs own risk and whilst every eort has been made to
ensure its validity, neither LightWare Optoelectronics (Pty) Ltd norits representatives make any warranties with
respect the accuracy of the informationcontained herein.
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2. Firmware change log
2.1. Upgrading
NOTE: The Upgrader tool only supports Microsoft Windows® at this time.
1. Download the LightWare Upgrader tool here: http://support.lightware.co.za/LightWareUpgrader-1.26.0.rar
2. Unzip the downloaded leto a location on your PC.
3. Run the le Li ght WareUpgr ader . exe in the unzippedfolder.
4. Connect your LightWare device via USB to your PC.
5. Click the COM port that appears.
6. If the device is not the latest version you can click the Upgr ade buttonto begin the process.
7. Wait until the upgrade has completed successfully and click OK .
2.2. 1.4.0
Changes
Improved noise issues.
2.3. 1.3.0
Changes
Modied Di st ance [ 105] commandto reportthe closest obstacle angle in 10thsof a degree.
2.4. 1.2.0
Features
Added a minimumdistance parameter for flightcontroller compatibility mode.
2.5. 1.1.2
Fixes
Flight controller compatibility mode now correctly uses the orientation setting.
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2.6. 1.1.1
Fixes
Version 1. 1. 0 had the LWNX protocoldisabled by default.It is now active by default.
2.7. 1.1.0
Features
Modied Di st ance [ 105] commandto accept a minimumrange parameter.
Modied Di st ance [ 105] commandto outputangle toclosest distance measurement.
Less aggressive power draw on the 5V line during start-up.
Supports ightcontroller proximitydetection when disabling LWNX mode.
Fixes
The Poi nt st ar t i ndex eldof the Di st ance out put [ 48] commandnow correctlytakes the Output
r at e [ 108] intoaccount.
2.8. 1.0.1
Notes
Initial release.
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3. Safety instructions
3.1. Overview
The SF40/C is a laser rangender that emits ionizinglaser radiation.The level of the laser emission is Class 1M
which indicates that the laser beam is safe to lookat with the unaided eye but must not be viewed using binoculars
or other optical devices at a distance of less than 15 meters. Notwithstanding the safety rating, avoid looking into the
beam and switch the unit owhen working in the area.
CAUTION --Theuse of optical instruments with this product will increase eye hazard.
The SF40/C should not be disassembled or modiedin any way. The laser eye safety rating depends on the
mechanical integrityof the optics and electronics so if these are damaged do not continue using the SF40/C. There
are no user serviceable parts and maintenance or repair must only be carried out by the manufacturer or a qualied
service agent.
No regular maintenance is required for the SF40/C but if the lenses start to collect dust then they may be wiped with
suitable lens cleaning materials. Make sure that the SF40/C is switched OFF before lookingintothe lenses.
The SF40/C should be mounted using the four holes provided in the circuit board. Do not hold or clamp the lens
tubes as this may cause damage and adversely aect the laser safety rating.
3.2. Labeling
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3.3. Laser radiation information
Specication Value /AEL Notes
Eye safety classication Class 1M
Laser wavelength 905 nm
Pulse width <20 ns
Pulse frequency <36 kHz
Peak power <10 W 50 millimeter aperture at 2 meters
Average power <0.6 mW 7 millimeter aperture
Average energy per pulse <300 nj
NOHD 15 m Distance beyond which binoculars with may be used
safely
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4. Specications
SF40/C
Range 0.2 ... 100 meters (natural targets)
Revolutions per second 5.5
Resolution 3 cm
Readings per revolution 3638
Readings per second 20010
Motor power supply
voltage 12.0 V DC (+-10%)
Motor power supply current 0.5 A (max)
Laser power supply voltage 5.0 V DC (+-10%)
Outputs & interfaces Serial UART 3.3V TTL
Dimensions 70 mm (height) x 79 mm (largest diameter)
Weight 256 g
Laser power 20W (peak), 11mW (average), Class 1M
Optical aperture 51 mm
Beam divergence 0.2°
Operating temperature 0 ... 40° C
Approvals FDA: 1410968-002(2018/09)
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5. Functional description
5.1. Overview
The SF40/C uses a scanning laser rangender to measure on a 360 degree disc witha radius of 100meters.
Collected data is stored in memory and continually refreshed as the laser scans around. The speed of rotationis 5.5
revolutions per second at a resolution of +-3 cm. This data can be used to triggerpredened alarm zones, give
informationabout target distances in any direction or streamed to a host controller withselectable outputrates.
5.2. Data streaming
Measurement data accumulated by the SF40/C can be outputto a host controllerfor immediate or deferred analysis.
The rate at which data is outputcan be selected as 20010,10005, 6670 or 2001points per second.
5.3. Alarms
Seven congurable alarms zones can be set within the measuring plane to alert obstacle proximity.Each zone can
be set with an individualized alarm distance, angular width and aiming direction. Typically, one zone would cover
360 degrees around the vehicle at close range to alert when people get too close to the moving parts. Additionally, a
forward lookingalarm zone is used to detect obstacles in the direction of motion.Other alarm zones can check that
specic directions are clear of obstructionsbefore course changes are made.
The status of the alarms can be read fromthe serial port througha command or from the streaming data. Once the
SF40/C is running the alarms are updated continuously withoutthe need for any external commands.
5.4. Virtual laser range nder
The virtual laser range nder(VLRF) tool is used to ndthe distance in any direction on the measuring plane. VLRF
can assist with keeping station at a xed distance froma target or measuring how far away an obstacle is. Any
number of VLRFs can be created that aim in dierentdirections. This allows for accurate position holdingwithina
conned space and provides conrmationof GPS location using adjacent buildingsor other known structures as
reference points.
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6. Hardware
6.1. Connector wiring
Serial UART (Pins 1 & 2)
3.3V TTL UART
Supports baud rates from 115200 to 921600
Laser power supply (Pins 3 & 4)
Power supply should provide 5 V +-10%
Power supply currentcapacity should be at least 0.2 A
Motor power supply (Pins 5 & 6)
Power supply should provide 12 V +-10%
Power supply currentcapacity should be at least 0.5 A
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6.2. Mounting on an airframe
6.3. Dimension drawings
25 (0.98)
25 (0.98)
M3 x M3 x 12 mm Hex
stando Male /Female
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6.4. Labeling
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7. Serial interface
7.1. Overview
The SF40/C uses a 3.3 V (5 V tolerant) TTL serial UART for communication.Communicationis performedusing
encapsulated packets for bothsending and receiving data. Every packet that is sent to the SF40/C is knownas a
r equest and a request will always be repliedto witha r esponse . There are cases where the SF40/C willsend a
request packet to the host, these packets are considered st r eami ng packets do not require a response fromthe
host.
Requests are made using one of the availablecommands and are either aggedas r ead or wri t e . When a read
request is issued then the response will contain the requested data. When a write request is issued then the
contents of the response will vary depending on the command.
Default serial interface properties
Baud rate: 921600
Data: 8 bi t
Parity: none
Stop: 1 bi t
Flow control: none
The SF40/Ccan operate in baud rates as low as 115200115200 but maximum data output will require higher
rates.
7.2. Packets
A packet for bothrequests and responses is composed of the followingbytes:
Header Payload Checksum
**Byte:** Start Flags
low Flags high ID Data 0 .. N CRC low CRC high
The St ar t byte is always 0xAA and indicates the beginningof a packet. It is importantto veryify that the payload
length is sane (0 to 1023bytes) and that the checksum is valid before processing a packet, rather than justrelying
on the start byte.
The Fl ags bytes form a 16 bitinteger thatrepresents the payload length and read/writestatus of the packet. The
payload length is inclusive of the ID byte and the required number ofdata bytes. The write bitis set to 1to indicate
write mode, or 0to indicate read mode.
**Bit:** 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Flags high byte Flags low byte
Payload length (1 to 1023) Reserved W
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The I D byte represents which command the request/response relates to.
There will be between 1 and 1023 Payl oad bytes (inclusive) depending on the command type. Each command
under the detailed command descriptions section documents how the data bytes are used. The I D byte will always
be present in the payload, therefore the payload length has a minimumof 1.
The CRC bytes form a 16 bitchecksum value used to validate the integrityof the packet data. Every byte in the
packet except for the CRC itself is included in the checkum calculation.
7.3. Checksum
Each packet has a 2 byte checksum which is used to validate data integrity.The algorithmis CRC-16-CCI TT
0x1021 (idendtical tothe one used for the XMODEM protocol).
The CRC mustbe correctly formedfor the SF40/C to accept and process packets. Below are some examples in
various languages forCRC calculation:
C/C++
ui nt 16_tui nt 16_t cr eat eCRC(ui nt 8_tui nt 8_t* Data, ui nt 16_tui nt 16_t Si ze)
{
ui nt 16_tui nt 16_t cr c = 0;
f or
f or (ui nt 32_tui nt 32_t i = 0; i < Si ze; ++i)
{
ui nt 16_tui nt 16_t code = cr c >> 8;
code ^= Dat a[ i ] ;
code ^= code >> 4;
cr c = cr c << 8;
cr c ^= code;
code = code << 5;
cr c ^= code;
code = code << 7;
cr c ^= code;
}
r et ur n
r et ur n cr c;
}
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Javascript
f unct i onf unct i on cr eat eCRCcr eat eCRC(dat a, si ze) {
l etl et cr c = 0;
f or
f or (l etl et i = 0; i < si ze; ++i) {
l et
l et code = cr c >>>8&0xFF;
code ^= dat a[ i ] & 0xFF;
code ^= code >>> 4;
cr c = cr c << 8&0xFFFF;
cr c ^= code;
code = code << 5&0xFFFF;
cr c ^= code;
code = code << 7&0xFFFF;
cr c ^= code;
}
r et ur n
r et ur n cr c;
}
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7.4. Receiving packets
Here is the process for reading the raw serial byte stream and identifyingpackets. Once a packet has been
successfully read it can be processed based on its commandID.
Start
Sucess
Read incomingbyte
Yes
No
Is startbyte? (0xAA)
Read 2 bytes: Flags (uint16)
No
Yes
Is payload
length 1 to 1023? Failure: packet length invalid
Read 'payload length'bytes
Read 2 bytes: CRC (uint16)
No
Yes
Is CRC valid? Failure: checksum invalid
Failure: invalid start byte
If the packet length or checksum is invalid then it is technically more correct to roll the incoming stream
back to when the start byte was found. However in practice this has little appreciable impact.
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7.5. Handling request & response
Every request sent to the SF40/C will receive a response, it is oftenuseful to use the response as a way to
determine if the request was received and processed. Here is the recommended procedure for sending a command
request and reading the response:
Start
Sucess
Send request packet
Wait up to 100ms for
response
No
Yes
Response packet
received?
No
Yes
Response
command ID
matches request
command ID?
Yes
No
Retries expired?
Error: No response received
The values used for timeout or numberof retries should be tuned to the specic application.
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8. Command list
ID Name Description RW Read
bytes
Write
bytes Persists
0Product name Product name R 16 - -
1Hardware version Hardware revision R 4 - -
2Firmware version Firmware revision R 4 - -
3Serial number Serial number R 16 - -
7UTF8 text
message
Human readable text
message - - - -
9User data 16 byte store for user data RW 16 16 Y
10 Token Next usable safety token R 2 - -
12 Save parameters Store persistable parameters W - 2 -
14 Reset Restart the unit W - 2 -
16 Stage rmware Upload rmware le pages RW 4 130 -
17 Commit firmware Apply staged rmware RW 4 0 -
20 Incoming voltage Measured incomingvoltage R 4 - -
30 Stream Current data stream type RW 4 4 N
48 Distance output Streaming distance data - - - -
50 Laser ring Laser ringstate RW 1 1 N
55 Temperature Measured temperature R 4 - -
90 Baud rate Serial baud rate RW 1 1 Y
105 Distance Single directiondistance RW 12 6 N
106 Motor state Motor state R 1 - -
107 Motor voltage Measured motorvoltage R 2 - -
108 Output rate Streaming point outputrate RW 1 1 Y
109 Forward oset Forward orientation oset RW 2 2 Y
110 Revolutions Number of revolutions R 4 - -
111 Alarm state Triggered state of alarms R 1 - -
112 Alarm 1 Alarm 1 configuration RW 7 7 Y
113 Alarm 2 Alarm 2 configuration RW 7 7 Y
114 Alarm 3 Alarm 3 configuration RW 7 7 Y
115 Alarm 4 Alarm 4 configuration RW 7 7 Y
116 Alarm 5 Alarm 5 configuration RW 7 7 Y
117 Alarm 6 Alarm 6 configuration RW 7 7 Y
118 Alarm 7 Alarm 7 configuration RW 7 7 Y
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9. Detailed command descriptions
9.1. Product name [0]
A16 byt e st r i ng indicatingthe productmodel name. This will always be SF40 followed by a null terminator.
You can use this to verify the SF40/C is connected and operational over the selected interface.
Read Write Persists
16 byt e st r i ng - -
9.2. Hardware version [1]
The hardware revision numberas a ui nt 32 .
Read Write Persists
ui nt 32 - -
9.3. Firmware version [2]
The version of currentlyinstalled rmwarerepresented as 4 byt es . This can be used to identifythe productfor
API compatibility.
12 3 4
Patch Minor Major Reserved
Read Write Persists
4 byt es - -
9.4. Serial number [3]
A16 byt e st r i ng (null terminated) of the serial identierassigned duringproduction.
Read Write Persists
16 byt e st r i ng - -
9.5. UTF8 text message [7]
Serial interface only
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