Based on infrared sensor with two fix holes spaced 20mm.
Sharp GP2Y0A21YK0F, IR distance sensor (10cm-80cm) -
I'd like to see the data sheet of this optical reflection sensor used to auto leveling, and its response, it's said that it's "Based on infrared sensor ", but I don't know if it's similar to my SHARP GP2Y0A21YK0F IR distance sensor
(and I guess NO, too inaccurate for the purpose of measuring micron)
I'd say it's a TCRT5000L with bend leads.
DescriptionThe
TCRT5000 and TCRT5000L are reflective sensors which include an infrared emitter and phototransistor in a leaded package which blocks visible light.
The package includes two mounting clips. TCRT5000L is the long lead version.
I just wonder about the analog part, I mean, the gain of the Operational Amplifier you have to use to amplify the output from TCRT5000L in order to see 1µm
is it possible?
The precision which can be attained mostly depends on the consistency of the reflectivity of the bed I think.
I think one half of the LM358 is used as a transimpedance amplifier and the other as a comparator.
Studying the data sheet, and looking around for professional solutions, I guess they(@PiBot-kit) say bullshit, I do not believe that sensor is able to have a resolution of nor 1um neither 0.1mm (100 um), I guess it's 0.5mm of resolution in the best case.
It's really hard to say, it sounds implausible but these sensors have a fairly wide beam and thus a fairly large surface reflecting and evening out any inhomogeneity in it. Over a long time it might not have repeatability with past measurements, but for a short term it might very well be able to very accurately match distances at different points which might be enough for this application.
As a pure end stop at constant temperature I wouldn't be surprised at all if it had micron level repeatability.