[VL53L4CD]What is the minimum measuring distance of the VL53L4CD?

[bbb888]

Question 1: What is the minimum measuring distance of the VL53L4CD? The official manual states it as 1mm, but in my actual tests, it fails to measure accurately when getting closer than about 1cm. At closer distances, the data becomes erroneous. Why is this happening?

Question 2: After modifying the I2C address of the VL53L4CD, can the change be retained even after power loss? In my current tests, every time the device powers up, I need to manipulate Pin X to change the address. However, upon the next power cycle, the address isn't saved and I have to reconfigure the device address again.

[John E KVAM]

Your data is correct. 

One some of our other sensors as the distance got below an inch or so, the distance started to go UP! This effect means one cannot really trust the distance below about 5cm.

the VL53L4s are different. A closer object will give a shorter distance, but unfortunately you run into accuracy issues. 

4mm +/- 4mm of accuracy means something is close, but due to accuracy issues you don't know how close.

In my testing, 7mm is about the lowest one can go and still get some degree of accuracy. So that might be about the practical limit. 

As to the I2C address, there is no persistent memory in the chip. So, you do indeed have to reload the I2C address after a shutdown.