Opple Light Master III (G3) discussion thread (Cheap device for measuring Lux, CCT + CRI)

Just noticed Opple EU is located in Eindhoven. Maybe pay them a visit :smiley:

… and make them put the R* values into the app while you’re watching.

Edit: And duv. Of course.

Off-topic a bit, but…

Ran into the same new version after I saw the one Opple uses is not recommended for new designs. Thinking of getting one of those small dev boards on AE (around 200 SEK for a nice Waveshare board) to play around with. Can also get a Sparkfun board, but s&h is more expensive than the board itself (e.g. Mouser).
Personally I’d hook it up the a wifi controller (ESP32/ESPhome), since I hate dislike bluetooth, but that’s details for another day. Biggest issue will be software that actually translates the raw ADC values to CCT, CIE 1931 coordinates, etc. And get a filter somewhere.

Fortunately there’s an application note / spreadsheet that comes with the eval kit. Might be useful.

Looks like AliExpress has been sold out of pros for a while. Anyone see the pro for sale else where with US shipping?

Well, my DIY lightmaster has arrived. August is too far away…

Now the hard part, the software. Probably better to start a separate topic, so those interested can follow any progress there and we don’t ‘pollute’ this thread. Hopefully more soon.

There’s an introduction to the Adafruit AS7341 and some examples using CircuitPython here:

AMS have a user guide for an AS7341 evaluation board that mentions calibration and CIE1931 XYZ Target Transformation. You may need to determine appropriate correction factors to apply.

https://ams.com/documents/20143/36005/AS7341_UG000400_5-00.pdf

The raw values for each frequency bin could be stored in some spectral power distribution object using the colour project for Python and then the CRI can be calculated:
https://colour.readthedocs.io/en/develop/generated/colour.colour_rendering_index.html

Only C for me :wink:

Have communication up and running and get raw output that makes sense. Calcs and calibration is next. AMS app notes will come in handy!

:sunglasses: What you are doing is far above my abilities. I hope you get fitting software running and I’m curious about the performance compared to a true spectrometer.

Any chance you can make your efforts into a separate thread? All these notifications are getting my hopes up for more Opple goodness. ;)

Hi all.
Just got my brand new Light Master 3, but it seems like it doesn’t work.
I am trying to charge it for the last few hours and nothing is happening. When I plug it in orange diode start to light. I assume it is ok. But If I open the device white diode doesn’t light.
How long does it take to charge it? Maybe I just need to wait some additional time.

Pretty sure they are back in stock now, FYI.

Nice!

All this excitement over gen 3 availability that WalkerTalker’s post is neglected.

There was an instance where one user had a faulty USB connector. However, the amber light wouldn’t turn ON.

I just so checked my unit and the flashing white LED works whilst charging. I did find out why at times I couldn’t connect – location services were OFF.

There is a small switch along the slider. This should be pushed in when fully opened.

Try pushing it with a needle – perhaps broken?

Hi. Thanks for your reply. Yes, I see that people were really waiting when the device is available and now it is available. At least in Europe. I bought it via amazon.de

Regarding your advice to push the switch. I had found it and tried to press it. It goes inside the case, and mechanically works fine but no luck. The device still doesn’t respond.
And if it should work during the charging, as you said, then it means mine is definitely dead :person_facepalming:
Thanks that you’ve checked the working state while charging

It’s really a bummer when you waited for so long only to have a faulty unit. However, Amazon will refund and you should get in touch with Opple if you are comfortable in bringing this to their attention.

I had previously tried to open my unit, thinking the hole at the bottom of the slider was to release an indent. But after much struggling, I couldn’t get it open and not wanting to break anything, I left it as such. If someone on the forum has found out how, this would be a nice time to chime in. Would definitely want to be able to fix anything mechanical / electrical, or at least try – if it’s broken, not much harm can be done.

PS: you should add the ‘d’ to your location.

I’ve been meaning to post for a little while, i have a unit with the same switch issue. On mine it’s caused by the inner unit being slightly misaligned with the outer casing which traps the switch in the ‘in-between’ state shown in Sidney Stratton’s photo.
For the unit to turn on the switch needs to be fully to the left in the photo (so towards the bottom of the unit as it stands upright) but it needs to be fully to the right for the unit to charge (so to the top of the unit as it stands upright), if it’s in the middle position it will neither turn on nor charge.

And i believe you will need to charge it first before it will turn on.

I can get mine to work (both turning on and charging) by kind of twisting the unit in the casing to free up the switch, but i have to do it with each movement and it’s awkward.

Having trouble following you. In my picture, the bottom of the unit is to the left. I slide the unit partly to expose that small switch (the magnified area).

Would you be saying yours is reversed, i.e. switched ON when closed / OFF when opened?

WalkerTalker’s unit has the amber light when plugged in. Doesn’t seem to complete the charge.

And mine does work while charging.

Here is my working Lightmaster 2 (LM2) on the left and the broken Lightmaster 3/Pro (LMPro) on the right.

The LM2 switch is in the ‘resting’ position which i refer to as ‘to the top’, if i were to lay the LM2 on it’s side in the same orientation as yours it would be ’ to the right’.
In this position the LM2 is turned off and charges.

When you slide the LM2 open, which in my picture means pushing the inner module upwards, the switch catches on the outer housing which pushes the switch downwards. In your picture you would slide the inner module to the right which would push the switch to the left. In this position the LM2 is turned on.

It should be the same for the LMPro but as you can see the switch is stuck in the middle, in this position the amber light illuminates when USB power is connected but the LMPro neither charges nor turns on.
I had the LMPro plugged in for 24 hours with the amber light on but when i manipulated the switch into the correct position for the first time it wouldn’t turn on, i had to connect USB power for it to turn on in this position.

Because of this i believe that the switch specifically needs to be in the resting position to charge (same as the LM2 in my picture), and neither my LM2 not the LMPro had enough power to turn on straight out of the box.

I also believe, but don’t know for sure, that when the unit is turned on the USB power will power the unit but not charge the battery.
I have another brand new LM2 (i bought a couple to make them easily available to UK members thinking i was buying the Pro :person_facepalming: ) so will hopefully be able to test that theory soon.

fwiw, I recently saw some screenshots from the Version 2 Opple. It has the XY coordinates, so DUV can be calculated, same as the Pro version.

the Pro has the Flicker measurement, and the CRI Ra

if someone does not care about those two items, they could buy the less expensive model, and still be able to measure CCT and DUV, just no CRI and Flicker

@ Marc E:

Regarding the LM pro:
Thanks for your detailed response. If I get this straight, it would seem the switch is hooked up (can’t slide) to the fully open position. So by twisting the inner sleeve it can overcome whatever is that’s binding. This led you to observe that the unit works off the USB charger but it’s not actually charging the battery (midway position).

Hence if WalkerTalker’s unit can’t charge (post #370), it wouldn’t turn ON being they are shipped with a drained battery (can’t recall how mine came in). So his switch isn’t responding.

I sure would like to know how to open these units. His or yours could be corrected.