2020-07-28 10:38 AM
Hi,
I have a project with VL6180X sensor. Moving from first prototype to second revision, I have realized that I have no use for AWS sensor. Therefore I can switch the sensor to the non-AWS having, also cheaper VL6180V. Datasheets of these sensors are almost identical. The datasheet of the V model has a absolute range of 62cm. However, the range register in question is only 8 bits long. The X variant works fine with this, of course since it is not possible to measure mm values greater than 0xFF mm (255mm) with the sensor (acording to the datasheet of the X variant). Is there hidden register somewhere where it is possible to read rest of the data or is there a mistake on the datasheet?
Here is a link to the datasheet in question. It is a download from your (ST's) VL6180V product page. https://www.st.com/resource/en/datasheet/vl6180.pdf
2020-08-03 07:30 AM
It's not exactly hidden, but you might have missed it. There is a multiplier you can set that will return 1/2 or 1/3 of the range value. So the max will be 255 (times the 3X multiplier.)
You do lose some resolution, but you gain the distance.
The datasheet on the sensors is almost identical, because the silicon is identical. We changed nothing, save we plugged the ALS hole, and do not calibrate the ALS. It saves us a few cents in the manufacturing, so we passed that savings on to you.
We have found very few customers have need of the ALS and it seemed silly to have to calibrate it.
Datasheet says:
2.12 Scaling
The default scaling factor is 3, which allows for maximum ranging capabilities. The scaling factor can be decreased to x2 or x1 for short range applications.
Note:With a scaling factor of 2/3. the reported range minimum resolution also increases to 2/3mm.
VL6180x_UpscaleSetScaling() is a single API function which allows the user to change the scaling factor of the device. VL6180x_UpscaleGetScaling() can be used to read the scaling factor.
Scaling factor = 1 = proximity ranging (up to ~20 cm)
Scaling factor = 1 = proximity ranging (up to ~40 cm)
Scaling factor = 3 = extended ranging (up to ~60 cm)