Probably mine just doesn’t connect.
I find it really weird that lightware doesn’t do anything about these many problems all users are having.
I got a replacement one for an SF20/C that doesn’t read any higher than 40 meters and the new one just doesn’t work.
Corrado
A little update. I had Lightware collaborate with me to solve my issues with lidar.
Last one they sent to me was updated with latest firmware and the authomatic selection of serial and i2c worked. I connected it and it shows values and works (i am using it on i2c).
I still have a problem i am working with them. My SF20/C (a decased version of te LW20/C) is unable to read above 60-70 meters, sometimes a bit more, sometimes a bit less. I sent lightware my latest log for them to review.
They are still reviewing the log but they told me that maybe the surface i am flying over is not reflective enough, it is strange because my other machine equipped with a SF11/C works perfectly up to 100+ meters and never gives a bad readings, flying over the same exact path.
Maybe the new small 20 series has a slightly lower performance/power laser and that is where the problems come from, i’ll wait and see what their diagnosys of the problem is and how/if we can solve it.
Got a final answer from Lightware, in the end they say it is normal that the SF20/C works up to 60-70m meters. It depends on surfaces i fly over, they say. Actually i fly over the usual grass, tarmac, cement.
They say 100 meters on the SF20/C is only reachable with a white surface (doesn’t say it on the site where they sell it).
So bottom line is, if you get an SF20/C or LW20/C expect it to be trustable up to no more than 60 meters. If you need something good up to 100+ meters regardless if you fly over a white wall or grass than get an SF11/C. It is a big bigger but it has almost twice the performances of the 20 series.
All in all i am not impressed by their answer and the not so truthful spec of 100 meters on the 20 series.
hi all. I need a rangefinder which is cabable of 50-60m REAL range outdoor. People which have opportunity to test the SF20, can confirm it works up to that? Thank you Corrado for your contributions, so far, although it doesn’t read up to 100m, if it does 50-60m it’s ok for me.
Range of a lidar sensor depends heavily on the environment and weather.
60-70 meters is only realistic in clear and dry weather conditions.
Slight mist, dust, haze will result in false readings at eventually even less than 15 meters.
During our testing and use, we found the SF11/C to have a much better range and an overall much better performance over the SF20/C.
50-60m range is really on the limit for the SF20/C.
This is my personal experience having tested both.
Hi all,
i bought 5 Lightware LW20/C. and used ArduCopter V3.6.6.
I update the LW20 firmware to V1.6.4
Startup mode to Wait for interface
Pixhawk I2C compatibility mode to On .Exit .Configuring the Pixhawk
RNGFND_TYPE = 7 (LightWareI2C)RNGFND_ADDR = 102RNGFND_SCALING = 1RNGFND_MIN_CM = 5RNGFND_MAX_CM = 9500.RNGFND_GNDCLEAR = 10I get 0.00 readings on the sonar range,SF20 can’t to work.
I have try another a SF20 set start mode is I2C, But the same SF20 can’t work…
@RobGowans Could you help me how to fix it?
Hi WangLouis,
It has come to our attention that ArduCopter V3.6.6. is not working with LightWare devices. I have tested V3.6.7-rc1 and everything is working fine again, so the problem has been resolved.
I am not sure yet at which version the problems started happening.
Hi RobGowans,
I have fixed it. very sorry, my cable is bad connection… XD
Hi WangLouis,
I’m glad to hear, but are you saying that you are getting distances while using ArduCopter 3.6.6?
Hi RobGowans,
yes, i am getting distances while using ArduCopter 3.6.6, works in Pixhawk 2.1. It is ok.
As a side note, Copter-3.6.7 includes a change that should improve the lw20’s ability to decide whether it should be in I2C or Serial mode.
Just as a note for anyone looking at this in future. It appears that only serial communication is broken in ArduCopter 3.6.6, the I2C still works there.
Rob. I am using the LW20 successfully with copter 3.6.6 on NutX, however I added a time delay relay between the lidar and the pixhawk that allowed the lidar to be powered on roughly 5 seconds after the pixhawk is powered. The lidar is powered separately from a 5V BEC.
Hi All,
I am using the LW-20B right out of the box. I am connecting it to a px4v2 board and my i2c values are all messed up. They are nowhere near correct. Should upgrading the firmware solve this @RobGowans ?
Hi Evan,
Can you describe the values you are seeing?
We also have a guide here that goes through updating and enabling an extra Pixhawk compatability mode here: https://github.com/LightWare-Optoelectronics/pixhawk-guide
Hi Rob,
I followed everything in that guide. And now it works just fine!
Thank you so much!!
Evan
Good to hear! Thanks for letting me know.
I think you should take out the 100 meters max range from the setup guide and put a much more realistic 60 meters. I tested it on any kind of surface, from tarmac to grass, from white walls to black, from absorbing superficies to reflective and 60 meters is what sf20 lidar can realistically read. I have 2 of them and both are giving same 60 meters performance.
I write this because people, like me, could think their unit is defective and under performs 
If someone had better result please share setup.
I have LW20/B and I had the same problem of 0.0 Sonar Range using I2C on a Pixhawk 2.1 with APM 3.6.9. I got the FTDI and upgraded the FW to 1.8.1. I think it was originally 1.6.0 (?). I changed Pixhawk compatibility mode to on. It seemed like all of that was successful. When I try the Lightware Terminal using the FTDI the operate function it shows the sensor working properly.
I cut off the FTDI and put the Pixhawk connector back on, but I still have zero sonar range,