Use a laser diode to make submicron measurements from a distance of several cm: [www.youtube.com] https://reprap.org/forum/read.php?1,841245,841245#msg-841245 Sun, 15 Mar 2026 06:48:59 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,841245,853812#msg-853812 https://reprap.org/forum/read.php?1,841245,853812#msg-853812 It may be easier to use a whole bunch of sensors with introduced noise and average the output – there may be a weight penalty however.

Mike]]> leadinglights General Wed, 22 May 2019 03:36:17 -0400 https://reprap.org/forum/read.php?1,841245,853796#msg-853796 https://reprap.org/forum/read.php?1,841245,853796#msg-853796 VL6180X Time of Flight optical sensor, and wondering about using it for measuring bed height.

However, the datasheet says the RESULT_RANGE_VAL and RESULT_RANGE_RAW registers only gives the distance in whole mm :( (despite being 16-bit registers). But I'm wondering if one of the other registers (RESULT__RANGE_RETURN_SIGNAL_COUNT perhaps? -- it's 32 bits) gives better resolution?

A comment at Sparkfun's forum says sub-millimetre can't be done, but you can't believe everything you read on the Internet.

There's a Hackaday project to do this.

Has anyone here done any experimentation with this device to get sub-millimetre measurements?]]> frankvdh General Tue, 21 May 2019 19:59:35 -0400 https://reprap.org/forum/read.php?1,841245,841253#msg-841253 https://reprap.org/forum/read.php?1,841245,841253#msg-841253 Was thinking about a vibration sensor based on that. Don't know if I still have somewhere this kind of diode. Would help here as no contact, no additional mass. Beats the smarphone attached with duct tape to the frame, gantry ....]]> MKSA General Thu, 13 Dec 2018 09:16:04 -0500 https://reprap.org/forum/read.php?1,841245,841250#msg-841250 https://reprap.org/forum/read.php?1,841245,841250#msg-841250
Some time ago I built bed height sensors that used ultrasound to measure bed height. Because the speed of sound is so much slower than light, the timing is much easier. Unfortunately the speed of sound varies too much with temperature for it to be a good solution, even when the height is compensated for changes in bed temperature.]]> dc42 General Thu, 13 Dec 2018 08:35:18 -0500 https://reprap.org/forum/read.php?1,841245,841245#msg-841245 https://reprap.org/forum/read.php?1,841245,841245#msg-841245
[www.youtube.com]]]> the_digital_dentist General Thu, 13 Dec 2018 07:36:43 -0500