Dear Sebastien
This is Nasir and currently i am working on self positioning robot based on LIDAR sensor. for that i have 51duino “51duino Smart Car Robot Driver Board 51 Development Board for Motor Servo Sensor for Arduino” and RPLIDAR A1M1 (i hope you are familiar with this 360 degree scanning). But i am having troubles in connecting these two circuits…anything on how to connect these two circuits/devices??
I appreciate you concern and help in advance…
@Nasir Nuru: We recommend that you contact the manufacturers of those two boards directly to obtain the documentation and support required for your integration issue. Another solution would be to write about it on our projects oriented website, Let’s Make Robots.
Hi Sébastien,
I’m mounting the LiDAR-Lite v2 on a drone and I only need the readings from it while it is facing down, would I still need the servo motor attachment to generate a point cloud? Can a point cloud be generated without the use of the servo motor or is it required to figure out the spherical coordinates?
@Jedidiah: To get a point cloud of spherical coordinates, you need 3 components: the polar angle, the azimuth angle and the radial distance. The distance is provided by the LIDAR-Lite. To get the two angles, you would need two servo-motors to produce them, not one. Another option, if your drone has the ability to do so, is to keep it stationary and then angle it to create the angles needed for the measurements of the LIDAR-Lite. If you wish to discuss this in more details, we recommend that you post about it in the forum.
Hello Sébastien; I am trying to build an altitude hold feature on my large Buffalo C115 R/C rescue plane. It needs to hold a 20 -30 cm altitude off our GRASS runway in full sunlight ( It will drop a R/C jeep out the back cargo door.) IR range module and ultrasonic ping does not work. Can a LIDAR accomplish this? Here’s what I’ve done sofar… https://www.youtube.com/watch?v=MOSbXaUq98c
R/C jeep out the back usually in full sunlight
Can it be used underwater? If not, what would the procedure be to waterproof it?
Hi Sebastien
Is it possible to point this LIDAR to mirrors and build a 2D or 3D RangeFinder ???
@Mohammad: Yes, it is possible to use a mirror. You can find some examples online of some projects doing just that! It has the added benefit of not needing a slip-ring as you can simply move and rotate the mirror around instead, keeping the LIDAR-Lite stationary.
@Hazem: The LIDAR-Lite cannot be used underwater as the casing is not waterproof. Also, even if it was (or made to be, without interacting with the casing’s optics), you would face a few major problems:
- Refraction will make the beam take paths that are not direct (and hard to predict), which will lead to (possibly large) errors in measurement that would need to be corrected.*
- Particles in the water will also absorb and scatter the beam, which will lead to loss of signal or errors (these ones are harder to correct).*
- The IR laser (and optics) used in the LIDAR-Lite is quite probably the wrong type for underwater use (since it is not meant for underwater use) and also may need to be more powerful.
#1 & 2 would most likely need the firmware to be modified to account for those. #3 would need different hardware.
@Frank Musil: Nice video! If powered and oriented properly, the LIDAR-Lite should have no issue with full daylight (due to the way it processes the signal sent/received). Please note that for reliable operation (due to parallax with the optics), it usually needs at least 20-30 cm to an object to report the proper measurement (some customers have reported success with distances as small as 10 cm).
Thanks Very much, Sebastien
I’m sorry, but questions keep coming:
How much is the minimum dimension of the object for measurements ? In what kind of conditions should I worry about the distance between sender and receiver ?
@Mohammad: In theory, to get a proper signal back, the object should be at least as large as the beam emitted by the LIDAR-Lite. Since the beam’s divergence is very small (~0.5 degrees), at around 40 m (the typical maximum distance for this sensor), the beam would be roughly 40 cm wide. If your object is smaller than the beam, it may only partially reflect (or not at all / not significantly enough, if it is too small) the beam and it will take longer for the sensor to get a proper measurement (you can change the maximum number of measurements in the registers). For more technical details, we recommend that you post on the forum.
hi,Sébastien
I have a question about the beam width (shape,width and angle ) ???
Hi Sebastien,
For my project I want to use 3 lidar sensors and 3 servo motors. Can I use 1 arduino to control them or would I have to use 3 separate ones?
Hi I wanted to use Lidarlite for water Level Measurement from height of 25 meters. I am successful at measuring. But I need more readings and then average it. What would be the minimum time delay between each successive measurements?
@Augustine: It is possible to use only one Arduino, though you will certainly run into power issues. In fact, in some cases, the 5V pin of the Arduino does not provide adequate power for just one LIDAR-Lite v2, so three of them would certainly be an issue. We recommend that you use an external 5 V DC power source with good current capacity. A possible solution would be a 5 V step-down voltage regulator such as RB-Pol-115 with a powerful enough wall adapter, such as RB-All-40 or RB-Ada-135. You may want to use a barrel connect to screw terminal adapter to connect the wall adapter to your voltage regulator, such as the RB-Dfr-182. We do not have much data on using three sensors together on the same I2C bus so that is something to be tried. If it did not work, you could still use only one Arduino by cleverly using the others pins to simulate I2C buses in software.
@Manjunath: While we can approximate the minimum time delay, in reality is it unknown since it is directly proportional to the number and strength of returned signals. And this varies based on external conditions such as distance to target, reflectivity of the surface, angle of the surface, environmental conditions between the target and sensors (rain, fog, snow, etc.). All of these things will affect the minimum duration of a measurement. What we do know is the maximum duration of a measurement by setting the maximum number of samples to take (set in the registers) to obtain a valid measurement. You can try and changing this value (lower to make it faster, high to make it slower) and see what kind of results you get. A good idea would be to setup your measurement to be at its absolute worst case (longest distance, least reflectivity, etc.) and then incrementally lower the maximum amount of measurements until the results become unreliable. Then use a slightly higher value and check how long those measurements take. This should be the maximum amount of time a measurement will take and will help determine how fast you can repeat measurements in your specific situation.
Hi Sébastien,
Thank you for the great sketch and example here for the PulsedLight3d module. I had planned to do something similar for a project which I am working on and then I found your site and voila! Excellent. Anyhow, I purchased and built your entire setup and (some soldering issues aside) got it running in about 15 minutes. I’ve since made a few modifications to the Sketch so as to include:
- updated sketch to include the pulselight3d library code to get all the features of their examples (https://github.com/pulsedlight3d)
- Changed the output format to a framed binary representation with a 3-byte synch word, tested to run in realtime at 115 Kbaud
- developed a serial framing and user-space capture library for Linux
- developed an SDL based 180-degree Radar-screen rendering application with a 3-point memory and phospor style fading
- developed up/down scaling in realtime to see near/far objects
- developed color based temperature/distance measurement display
- output stats in realtime (distance, closest/furthest)
I’m thinking this may be interesting to you and/or anyone else who would like to further their developments with LIDAR scanning using this module and some of the great products you guys sell at your store.
If anyone is interested, let me know, I may post the project to github in a few days as I have some free time now.
Hello Sebastien
We have a fish farm on the field and having trouble with birds eating our fishes. I made an arduino prototype which scans the sky and upon detection it plays wierd sound, then a shotgun fired sound and finally sprays pressured water against the locked target. Now I want to build this project in real, would you suggest this laser distance rangefinder for my project. Would it work for detecting birds over 40m. distance. (birds are 40 cm. height and with wings open they are about 90 cm. wide)
Best Regards