Two VL6180x sensors question

[jerryterry4103]

Posted on June 03, 2014 at 00:50

Is it possible to mount two of these sensors about 10 cm apart facing each other, without interference?  And when an object is inserted between the sensors be able to measure the thickness of that object by subtracting the difference?

One last question is there example code of how to perform a measurement reading?Thanks! Jerry T. #vl6180x

[Colin RAMRATTAN]

Posted on June 04, 2014 at 21:26

Hello Jerry,

Here are the answers to your questions.

If you mount two sensors 10 cm apart and initiate a range measurement from both of them at the same time then they will interfere with each other. Considering your application where you want two sensors to measure the thickness of an object, this can be done with some help from the HOST processor. One sensor can be used to continuously detect if there is an object placed in the field of view for measurement. Once an object is detected the HOST processor can initiate single-shot range measurements from the second VL6180X. The end result is measurement from both sensors which will allow the HOST processor to calculate the thickness of a material in question.

The second way to use two sensors facing each other is to use the range intermeasurement period, register 0x001B, feature. This feature can be set for a desired “sampling� rate. If the intermeasurement period is set to 4 times the max convergence time setting and the measurements are started out of phase to each other then, the VL6180X devices will not interfere with each other immediately. However, they will interfere with each other eventually but the timescale for this interference is not known as this depends on internal oscillator drifts over time.

For the sample code, I can definitely send you an example using our STM32 primitives. Please email me at

mailto:colin.ramrattan@st.com

for the sample code.