Problem with Lidar Lite v3

Help & Support Robot Parts
1

Hi

When I get the distance between the Lidar Lite 3 and an obstacle, I don’t get correct values, for example

Lidar value True value
52cm 27cm
24cm 11cm

I have tried with a raspberry pi and an arduino.

Thanks or any hint …

Cheers

Karim

2

and if i put something just in front of it it says ~ 30 cm instead of 0

3

Hi Karim,

The official range is actually up-to 40 m, due to the optics of the device, measurements under 30 cm are not reliable.

This would most likely explain the results you are getting. Did you try at longer ranges and how did it perform?

Sincerely,

4

Hi

I have tried too at ~ 2m and same problem.
If I put something on the lidar, I should read 0, shoudnt’I ?
I will try with the pwm mode too

Cheers

Karim

5

As mentioned, distances under 30 cm are not reliable. Covering the emitter or receiver is an undefined situation, therefore you may get 0 cm (seems like a logical expectation), but you may not.

6

Same problem with pwm

I did these measures :

Lidar True Difference
110 94 16
260 243 17
75 60 15
161 152 9

It seems there is an offset of ~15 cm (except for the last one)

7

Hi,

Interesting results.

In theory, the specifications (on page 2 of the datasheet) mention an accuracy of ±2.5 cm under 5 m (also specifying non-linearity below 1 m).
That being said, those specs are based on a flat, 70% reflective surface “perfectly” perpendicular to the sensor. It is very likely that you are using the sensor against a surface that is not “perfectly” flat, 70% (or more) reflective and perpendicular to the sensor. Also, strong light sources (or complete lack of them) around the sensor do seem to change the results a bit, too.

Therefore, this seems like reasonable results depending on the quality of your test conditions.

A few other things to check that may also affect measurement quality:

]Do you have the mandatory 680 µF capacitor between the VCC & GND pins of the sensor?/:m]
]Do you have a strong enough 5 V DC power source for the sensor (must provide at least 500 mA @ 5 V DC without dipping on power-up)?/:m]
]Is your 5 V DC power source free of noise/ripples/etc.?/:m]

We hope this helps investigate the situation.

Sincerely,