I am not sure what you are trying to ask.
Let’s do this a different way:
Do you want:
- Repeatable accuracy to ±0.001 meter? (i.e. ±1mm)
– or –
- Readings that have more digits of precision ? (i.e. instead of 0.01 meter, readings of 0.001 meter?)
For number 1, that entirely depends on the specifications of the sensor itself, ambient noise, temperature, humidity, what is in the room with it such as furniture, carpet, or curtains, and maybe even other things. You will need to find the technical data sheet for the actual sensor itself to find out if it is possible to get the accuracy you need. Maybe? Maybe not?
For number 2, I would suggest that you look at the grovepi sensor libraries themselves. Maybe the library reads more digits of precision from the sensor, but rounds to the centimeter?
I am not an expert on the Grove Pi system and I do not have that particular sensor. However, if I had one, and had these kinds of questions, this is what I would look at first.
I DO have a GoPiGo, and I have had similar questions in the past. The way I solved these problems was both to ask here, (a good idea!), and to look at the device and its programming libraries.
Perhaps someone who knows more about the Grove Pi system can help?
Please reply and let us know what you discover!
If I have not understood your question correctly, please reply and let me know.