LIDAR Sensor has arrived!

[seg9585]

Just wanted to share that a new LIDAR (laser radar/rangefinder) is out on the market from "PulsedLight3D" for $90 -- Class I laser so it's FIRST legal. Just arrived today in the mail, and I hooked it up to my Arduino:



Did some initial testing via I2C, seems to be very accurate between ~20cm and 650cm (as far as I could test it tonight without finding a larger room), 0.5 deg beam width

Here's a snapshot of my Serial output with distance in cm (~100 Hz samples averaged and output at 5 Hz), sitting on my desk facing up to the ceiling.


http://pulsedlight3d.com/
We're going to have fun with this!

[AllenGregoryIV]

We got ours today as well. Similar results to your tests. Very excited about this little guy.

[runneals]

Being a geospatial geek, this is TOTALLY COOL!!!!!!!

[TylerStaudigel]

This might be a newbie question, but this can be connected to the robo-rio via the I2C and programmed in labview to give us the distance. Right. I haven't done much work dealing with I2C and am not sure what to expect.

[seg9585]

Originally Posted by TylerStaudigel

This might be a newbie question, but this can be connected to the robo-rio via the I2C and programmed in labview to give us the distance. Right. I haven't done much work dealing with I2C and am not sure what to expect.

The sensor has 2 output formats: I2C and PWM. I have tested via I2C and it works great. To use PWM, you'd need to create a low-pass filter to smooth the output which could then be read by the roboRio analog input.

I will be coding up a Java Class this week to interface with I2C on the roboRio, which I'd be happy to share.

[tech2077]

In case anyone is interested, I wrote up a java class for this, you can use the start/stop functions to use the built in updater Timer, or use the update function to only poll distance when needed.
LIDAR.java

[seg9585]

Originally Posted by tech2077

In case anyone is interested, I wrote up a java class for this, you can use the start/stop functions to use the built in updater Timer, or use the update function to only poll distance when needed.
LIDAR.java

tech2077, are you having any luck with this code? When I attempt to run I get zero distance data. Also, the i2c.read() function returned "true" (aborted). I'm passing in Port.kOnBoard and the sensor is plugged into the I2C port on the roboRio

[tech2077]

Strange, it has worked for me. I've been using the mxp port so far, so I'll test with the on board one.

[tech2077]

Right now it seems that only the MXP port is supported with the LIDAR, I'm still investigating, but using the same power source and code, only the MXP I2C port will return data.

[Poseidon5817]

Dimensions: 21 X 48.3 X 35.5 mm
• Performance: Range: 0-40m Laser Emitter
• Accuracy: +/- 0.025m
• Power: 5vdc, <100ma
• Acquisition Time: < 0.02 sec
• Rep Rate: 1-100Hz
• Interface: I2C or PWM
•Max Operating Temp.: 70° C
•Eye safe, laser hazard free

Works up to 40 m, + or - 2.5 cm, <20 ms acquisition time.

We have ordered one.

[seg9585]

Originally Posted by tech2077

Right now it seems that only the MXP port is supported with the LIDAR, I'm still investigating, but using the same power source and code, only the MXP I2C port will return data.

Ah, thank you! I originally wrote up my own test code without the scheduler implementation and couldn't get it to work in this port, so I switched to yours with similar results. They seem to work just fine in the expansion port, making me curious if the I2C onboard has a bug or is otherwise disabled on the roboRio. I'll contact NI and let them know.
For now, works perfectly on the MXP, thanks again!

[JesseK]

I might get one of these to poke around with. Our programming team is talking crazy talk for autonomous, and I don't know that the drive train will have quite the precision they require to squeak in under 15 seconds.

Anyone tried this out on diamond plate? I bet more than my team has felt a twinge of failure with ultrasonics when moving from the lab to the field.

[tech2077]

Originally Posted by seg9585

Ah, thank you! I originally wrote up my own test code without the scheduler implementation and couldn't get it to work in this port, so I switched to yours with similar results. They seem to work just fine in the expansion port, making me curious if the I2C onboard has a bug or is otherwise disabled on the roboRio. I'll contact NI and let them know.
For now, works perfectly on the MXP, thanks again!

Poking around the linux side with i2ctools there are definitive read/write errors showing up for the onboard port, so I'll be sure to let them know.

Originally Posted by JesseK

I might get one of these to poke around with. Our programming team is talking crazy talk for autonomous, and I don't know that the drive train will have quite the precision they require to squeak in under 15 seconds.

Anyone tried this out on diamond plate? I bet more than my team has felt a twinge of failure with ultrasonics when moving from the lab to the field.

Anything solid and IR opaque should have good data from this sensor. The diamond plate will definitely give good distance readings, but totes and lexan still need to be tested.

[DavisC]

Originally Posted by tech2077

In case anyone is interested, I wrote up a java class for this, you can use the start/stop functions to use the built in updater Timer, or use the update function to only poll distance when needed.
LIDAR.java

How do you (or anyone that has gotten this to work) implement this with the main class. I specifically am using the "Getting Started" example.

I tried using it something like this (don't have the exact code in front of me...):

Where variables are declared:

LIDAR myLidar = new LIDAR(port.kOnboard);

then in teleopPeriodic() I did:

myLidar.update();
System.out.println(myLidar.getPID());

However, 0.0 is only ever printed out to the Riolog. (I also tried having the myLidar.start() and myLidar.stop() inside of teleopInit and disabledInit respectively.

Thanks in advance,
DavisC

[tech2077]

Originally Posted by DavisC

How do you (or anyone that has gotten this to work) implement this with the main class. I specifically am using the "Getting Started" example.

I tried using it something like this (don't have the exact code in front of me...):

Where variables are declared:

LIDAR myLidar = new LIDAR(port.kOnboard);

then in teleopPeriodic() I did:

myLidar.update();
System.out.println(myLidar.getPID());

However, 0.0 is only ever printed out to the Riolog. (I also tried having the myLidar.start() and myLidar.stop() inside of teleopInit and disabledInit respectively.

Thanks in advance,
DavisC

It's been discovered that the on board I2C port is having communication problems, use the I2C on the MXP port until the issue is resolved.