Question about the VCNL4000

[ymilord]

Can the VCNL4000 sensor detect small changes and report a value? i.e. I am wanting to use this detect how much material is left on a spool. Is this sensitive enough to detect a object thats about 2"~3.5" away and sense that the object has moved away 1"~3"? (As the material is being pulled off the spool).

Thanks in advance.

[adafruit_support_bill]

The VCNL4000 would probably work if you do not need great precision in the distance measurement.
These require a slightly longer working range, but would give more precise & repeatable distance reading. https://www.adafruit.com/products/164

[ymilord]

Hi, I just picked up the VCNL4000 sensor a couple of days ago. And I am having a issue where the values for the proximity sensor are not changing. They hover around 2312 to 2337 no matter how close or how far the object is. But The lux sensor values are changing/working correctly. I've tested this with the example code for the VCNL4000 from both adafruit and sparkfun. Both fire back the same results. I am starting to think there is an issue with the proximity side of the sensor.

Can you provide any assistance? Thanks!

[adafruit_support_bill]

This is definitely not the easiest sensor to use. It needs to be tuned for the application and is not capable of precise ranging.

Take a white card and hold it at 5mm from the sensor and take an average of 20 or more samples.
Repeat for 10, 20, 50 and 100mm and compare the average readings.

The noise floor can be pretty high depending on the lighting conditions. The difference between object detected/not-detected can be a small fraction of the raw counts. The test code simply reports raw counts. It does not apply any noise-floor or detection thresholds since these would vary from one application to another.

See page 5 of the application note: http://www.adafruit.com/datasheets/vcnl4000AN.pdf

[ymilord]

Thanks for the reply. I've ran those tests several times in the last couple days and I retried it today as suggested.
I used a piece of index card and moved it back and forth in front of the sensor. The value hovers at around 6~17 counts.

As a test I pointed my point and shoot camera at a standard remote and I was able to see. I attempted to do the same for the IR emitter on the sensor and I get nothing. Is there a variable that can disable/turn off the IR emitter? As that something that was settable in the example that you guy proved? (that's the only sketch I've used on it so far).

Thanks in advance.

[adafruit_support_bill]

The IR emitter only makes brief pulses during a proximity read. I don't believe it is possible to disable it.
We can try replacing the sensor. If you contact [email protected] with a link to this thread we can get one out to you.

[ymilord]

Thanks Bill. I did and got a prompted response. Thanks for all the help!