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From version < 143.5 >
edited by Xiaoling
on 2022/06/10 17:26
To version < 143.4 >
edited by Xiaoling
on 2022/06/10 17:25
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857 857  
858 858  === 2.10.2  Replace the battery ===
859 859  
860 -(((
861 861  You can change the battery in the LDDS75.The type of battery is not limited as long as the output is between 3v to 3.6v. On the main board, there is a diode (D1) between the battery and the main circuit. If you need to use a battery with less than 3.3v, please remove the D1 and shortcut the two pads of it so there won’t be voltage drop between battery and main board.
861 +
862 +
863 +The default battery pack of LDDS75 includes a ER18505 plus super capacitor. If user can’t find this pack locally, they can find ER18505 or equivalence, which will also work in most case. The SPC can enlarge the battery life for high frequency use (update period below 5 minutes)
864 +
865 +
866 +
867 += 3.  LiDAR ToF Measurement =
868 +
869 +== 3.1 Principle of Distance Measurement ==
870 +
871 +The LiDAR probe is based on TOF, namely, Time of Flight principle. To be specific, the product emits modulation wave of near infrared ray on a periodic basis, which will be reflected after contacting object. The product obtains the time of flight by measuring round-trip phase difference and then calculates relative range between the product and the detection object, as shown below.
872 +
873 +[[image:1654831757579-263.png]]
874 +
875 +
876 +
877 +== 3.2 Distance Measurement Characteristics ==
878 +
879 +With optimization of light path and algorithm, The LiDAR probe has minimized influence from external environment on distance measurement performance. Despite that, the range of distance measurement may still be affected by the environment illumination intensity and the reflectivity of detection object. As shown in below:
880 +
881 +[[image:1654831774373-275.png]]
882 +
883 +
884 +(((
885 +(% style="color:blue" %)**① **(%%)Represents the detection blind zone of The LiDAR probe, 0-10cm, within which the output data is unreliable.
862 862  )))
863 863  
864 864  (((
865 -
889 +(% style="color:blue" %)**② **(%%)Represents the operating range of The LiDAR probe detecting black target with 10% reflectivity, 0.1-5m.
866 866  )))
867 867  
868 868  (((
869 -The default battery pack of LDDS75 includes a ER18505 plus super capacitor. If user cant find this pack locally, they can find ER18505 or equivalence, which will also work in most case. The SPC can enlarge the battery life for high frequency use (update period below 5 minutes)
893 +(% style="color:blue" %)**③ **(%%)Represents the operating range of The LiDAR probe detecting white target with 90% reflectivity, 0.1-12m.
870 870  )))
871 871  
872 872  
897 +(((
898 +Vertical Coordinates: Represents the radius of light spot for The LiDAR probe at the different distances. The diameter of light spot depends on the FOV of The LiDAR probe (the term of FOV generally refers to the smaller value between the receiving angle and the transmitting angle), which is calculated as follows:
899 +)))
873 873  
874 -= 3.  Configure LLDS12 via AT Command or LoRaWAN Downlink =
875 875  
902 +[[image:1654831797521-720.png]]
903 +
904 +
876 876  (((
906 +In the formula above, d is the diameter of light spot; D is detecting range; β is the value of the receiving angle of The LiDAR probe, 3.6°. Correspondence between the diameter of light spot and detecting range is given in Table below.
907 +)))
908 +
909 +[[image:1654831810009-716.png]]
910 +
911 +
877 877  (((
913 +If the light spot reaches two objects with different distances, as shown in Figure 3, the output distance value will be a value between the actual distance values of the two objects. For a high accuracy requirement in practice, the above situation should be noticed to avoid the measurement error.
914 +)))
915 +
916 +
917 +
918 +== 3.3 Notice of usage: ==
919 +
920 +Possible invalid /wrong reading for LiDAR ToF tech:
921 +
922 +* Measure high reflectivity object such as: Mirror, Smooth ceramic tile, static milk surface, will have possible wrong readings.
923 +* While there is transparent object such as glass, water drop between the measured object and the LiDAR sensor, the reading might wrong.
924 +* The LiDAR probe is cover by dirty things; the reading might be wrong. In this case, need to clean the probe.
925 +* The sensor window is made by Acrylic. Don’t touch it with alcohol material. This will destroy the sensor window.
926 +
927 += 4.  Configure LLDS12 via AT Command or LoRaWAN Downlink =
928 +
929 +(((
930 +(((
878 878  Use can configure LLDS12 via AT Command or LoRaWAN Downlink.
879 879  )))
880 880  )))
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