Finally! Cheap TOF Laser Rangefinders are here :)

See this VL5310x based module.

Chip info here.

If I only had snow to measure…

The snow here is rapidly disappearing.
I saw another version of a Time of Flight laser measurement chip from Parallax, and I think can be found here, if I cut and pasted correctly. There is a little video of it being used, and the readout visible is happily jumping one centimeter at a time. If that is close enough, seems like a project for folks to work on.

https://www.parallax.com/product/28041

That uses the same chip as the ebay board. It’s supposed to have 1mm resolution, +/- 3% accuracy and 4 feet range. Not as good as the much more expensive Fluke but should be good enough for many users’ hobby use.

hi

l am wondering if this could be added to the ir sky temperature sensor board?

as a add on sensors

ir sensor plus solar, uv, rain, light, snow

mick :smiley:

I need to think about the best way to do that :slight_smile:

Update: I ordered one to play with, it’s on a slow boat from China…

one on it way to me, :smiley: have not got a clue how long it will take to arrive
mick

Received one today :slight_smile: Wow, this thing is tiny 8O Should have looked at the dimensions, I had assumed the pads were for 0.1" headers, but they are 0.05" spacing…

I have it working with a PC terminal program and a USB → TTL Serial adapter. Haven’t checked the accuracy yet but the numbers look to be in the ballpark. Good progress for a couple of hours :smiley:

Niko,
Keep some notes, or some photos of what you did so those of us who wish to dabble can learn from your work, or just plain copy it to get some experience.

Is there anything about the duty cycle of the sensor? I know the folks who were working so hard on the Fluke/Porcupine combination that was so accurate were saying that the Fluke was sensitive to duty cycle and were only firing up the laser occasionally to try to maximize the expensive rangefinder. That just adds to the complexity of the programming and some degree the hardware.

I know these things are breath-takingly cheap but still to fry one to just pop another in seems wasteful.

Anything you’ve seen in the spec sheets on whether these can just be made, placed and then powered up to run?

Thanks for the update. Your reports are encouraging.
Dale

hi

amazing
still waiting for the post man ,
cannot wait to get this hooked up to Cloud IR sky temperature Project + addon uv - solar - rain plus snow sensor
this Project was only possible by Niko
thank you
http://www.weather-above.com/skyirtemp.html

It waits for a command and replies with an acknowledgement (if it was a setup command) or data (if it was a measurement command) so the user is in control of how hard it works.

Anything you've seen in the spec sheets on whether these can just be made, placed and then powered up to run?

There are so many possibilities I’m not sure how to answer that :dontknow: It doesn’t match any of the devices that WD currently supports for snow if that’s what you are thinking of. Probably the simplest would be an interface to make it look like the MB7354 ultrasonic sensor that WD does support. Anyone wanting to do their own thing can connect it to a PC with a cheap serial module and a simple program (Python?) can collect the data and upload to a website.

MichaelPT’s multi-instrument has a processor that is already collecting data from several sensors so hopefully we can just poll this sensor and add the data to packet it is sending to the PC.

One issue is that it is only sure to be good for about 1 meter/3 feet of snow, so I could see needing to build a unit with two sensors at different heights to extend the range.

Having this in test running on RasPi and measuring snow.
Gives OK values only when its dark outside. During daylight are the values (depending on temperature-fix) ca 195 cm.
This occurs only on snow, on soil, water etc is it OK.

weatherc:
Is the chip that doesn’t do well in the sunlight the Parallax chip, or the one that Niko is testing? I take it there are two different ones, from the links and not just a re-packaging of the same one.

I was worried about that, I’ll find some fake snow and test it later when the sun is up. The sensor chip datasheet claims "The VL53L0X

The Parallax one

It’s the same sensor component so it’s no surprise that I confirm weatherc’s results. Styrofoam sheet in bright shade is fine, but in full sun results in an FF error value in the serial data. Not unexpected from such a tiny micropower laser.

I guess a snow sensor that only measures overnight is probably still worthwhile considering the very low cost? At least it would show daily totals…

At least up here north at 60

Hi
this is probably going to be a silly suggestion, have you tried putting a sunglasses lens that are mainly clear then as the sun get brighter they go darker
some kind of reactive plastic lens

Just wondering if the laser sensor will go through such a thing but could help eliminate the bright light
mick

The reflected solar radiation from a white target is many, many times stronger than the reflected signal from the tiny micropower laser. (When you receive yours you will see just how tiny it is.) Anything we do to optically reduce the reflection will also reduce the laser reflection so it doesn’t change the situation, and it has to be out in the open otherwise the snow will be obstructed. Short of automating a sunshade when taking a measurement I don’t see any way out of this one :frowning:

Sounds like a job for a narrow bandpass filter - if you can find one at the correct frequency.

Agreed, the chip has one already, and one hopes the laser signal is modulated to separate it from the “DC” sunlight. However it’s a 940 nm laser and there’s a LOT of IR energy in sunlight at that wavelength :frowning: