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VL53L7CX range fluctuation

Rick Hamilton
Associate II

Hi I am developing a commercial footfall counter based on the VL53L7CX and ESP32.

The API is (Version : VL53L7CX_1.2.10)

I have produced a mockup using the VL53L7CX breakout board.

IOVCC is 3.3 volts
I am using the on board regulator for AVDD powered from 5 volts.

I2C is 1 MHz.

I am using the 4 x 4 resolution.

I am only using the Results.distance_mm the rest of the Structure and I2C communication is disabled in the platform.h

I have developed a PC app to capture the ranges and visualize the range data.

With the sensor facing a blank wall 3000 mm away I am getting a mixture of ranges in the 16 zones with almost 2000mm difference on adjacent zones.

I have also found some zones just do not update their range unless you wave your hand in front of the sensor.  This is not a data issue I am receiving the data it just does not change.

The worse problem I have is the range on some zones is intermittently fluctuating by more than 400mm between samples.


I have tried ranging frequency from 2 to 60 Hz (Along with Integration time 2ms to 1000ms)

I have tried setting the sharpener percentage 0 to 99

I have tried the xtalk calibration.

I have tuned out all the lights in the room is is no ambient light.

I can not continue with this sensor unless I can make the ranges consistent what else can I try?

Thank you.




ST Employee


From your description, 3-meter target return signal rate is too low to get a valid range result. 

May I know a bit more about your test setup, 

  • What's the target material is, is it a high reflectance target? is it a diffuse reflection target. 
  • Have you tried short distance, is it same issue, or much better. 
  • suggest you also output the range status, status 5 is a valid output. if the range result on certain zones is not update, that means no target was detected, and status will not be 5. 
  • From your description, seems you are testing with a cover glass on top of VL53L7CX? as you have tried xtalk calibration, can you remove it and have a try.

Below is my test result more than 3 meter with 5hz range frequence.

  • R: range distance
  • P: return signal rate
  • A: Ambient level
  • S: Range status
  • Z: Zone number. 




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