VL6180V1 for measuring the level of water - Will it give me the height of water or distance of water from sensor

[RGura.1096]

Hello. I would like to measure the level of water in a closed container.

I have chosen VL6180V1 for the same since it has an 850 nm light source which won't be absorbed by water.

I have referred this article for it:

https://community.st.com/s/question/0D50X0000Bxwc5kSQA/i-would-like-to-use-the-vl53l0x-to-measure-the-height-of-liquids-in-the-holding-tank-and-water-tanks-of-a-boat-is-this-likely-to-work-distances-are-5-cm-50-cm

Now my question is "Will it give me the height of water or distance of water from sensor?"

I am curious to know this thing before I proceed. I would also like if there is any code example or user manual specific to my use case.

Please help me with this thing. I am in a dilemma whether to use this sensor or not.

[John E KVAM · Accepted solution]

With any of the ToF sensors, you are going to get the distance from the sensor to whatever it hits.

So as the water level goes down, the distance measured goes up.

We've learned a bit since that article.

1) you have to be really careful about the container. Some light will penitrate the water and bounce back. Best if you can use a flat, black bottom on your container.

2) perpendicular is the key. Only the photons that bounce perpendicular to the sensor can be trusted. The rest just provide noise. You really cannot tell which are which but by placing the sensor exactly parallel to the water, it works better - as the light is perpendicular.

3) after some thought the VL53L1X's ability to narrow the Field of View actually does OK as it can narrow the Field of View. But one must carefully design the bottom of the tank to make it as black as possible.