Closeup-Distance Measurement-Range: Min .125" to 4" Max

Hello Everyone,

I wonder if anyone can help me. I have been looking over the distance measurement sensors offered here on Sparkfun and have a couple of questions.

First, my intended application will have very short distance sensing requirement, as I stated in the subject line: Minimum .125" to Maximum 4".

I am gravitating toward the VL6180 Sensor, using the Arduino UNO or maybe the Mega 2560 R3 to control and interface, as it was the only one that clearly stated that the sensing range started at zero.

Can anyone tell me how accurate and precise this sensor is within that range?

If you think this sensor is not capable of that range, can you make any recommendations?

Thank you in advance,

Jeff

Have a look at the datasheet page 35 and / or setup and test yourself.

Calibration is most likely required.

DanV - Thanks for your reply. I had already reviewed the data sheet, specifically page 35, but, honestly, I didn’t understand the information. I was looking for someone who might have real world experience with this sensor that could relate to me the layman’s version.

What don’t you understand about :

Noise = 2mm max

Range offset error = 13mm max (Maximum offset drift after 3 reflow cycles. This error can be removed by re-calibration in the final system)

Temperature dependent drift = 9mm typical, 15mm max (Tested over optimum operating temperature range)

Voltage dependent drift = 3mm typical, 5mm max (Tested over optimum operating voltage range)

there’s also an application note that tells more:

https://cdn.sparkfun.com/datasheets/Sen … onNote.pdf

Ultimately, your specific application will determine the accuracy of the device - if you implement it poorly, he results will be poor. You should not expect to drop it into something and viola - it magically works beyond your expectations. Expect the opposite.

I thought I made a friendly request for information from anyone that might have experience with this sensor? I had read both the datasheet and application note before I posted the questions. I could probably attribute my ignorance on this topic to not being familiar with the terminology. I have never heard the terms: “Range Offset” or “Drift”.

I have a very limited budget of both time and money to produce an automation prototype, and am researching the available technologies I might be able use. I was trying expedite my understanding and get some user insights, same as I would if I had a colleague that had experience or knowledge that I do not. If that has somehow offended you, I apologize.

As for your eloquent closing: “…your specific application will determine the accuracy of the device - if you implement it poorly, he results will be poor. You should not expect to drop it into something and viola - it magically works beyond your expectations. Expect the opposite.” THIS IS WHAT I AM TRYING TO PREVENT!

Geez, dude, who pooped in your Wheaties?

I have no idea why you think I may have been offended. Nor do I have any idea why you appear to be offended.

You can find many many posters on forums that have done no research whatsoever and to help answer questions, the volunteers have to do the research instead. Maybe if you said you had looked over the datasheet and application note and also said that you had seen the specs and didn’t understand something listed there, you would have received an answer differently.

I am not now saying that you did anything wrong. The more information you provide, the better answer you can get.

I do have a colleague who has used the device but only as a proximity detector, not for actually measuring the distance. So, no help there.

Electronic devices are subject to drift because of temperature and voltage variations. Calibrate a device today, and tomorrow, after things have changed a bit, you’re looking at some funny readings.

good luck with your project.

DanV - Thanks for your follow-up. I guess we both assumed things about each other that were not correct. For my part in that, I do sincerely apologize. Participating in public forums can be a real crap shoot. In posts, elsewhere, it seems the more information I give, the less response I get. So, I usually try to minimize question detail to just what I need to know, in hopes of getting at least that in return. Anyway, thanks again, and take care.

EDIT: I just found this video for anyone else that might be interested: https://www.youtube.com/watch?v=NBV1Bg_Yj94

It convinced to try the VL6180 Sensor, I think it will work for what I need.