Introducing the MELD-X RGBW(uv) flashlight driver!

I’ll put some thought into it. I’m almost out of memory so I can’t add an interactive feature for setting up the different levels. What about picking a mixed color from the RGB mix mode (wouldn’t allow all three colors, but you’d get a configurable color added to the white)? Or maybe just an adjustable amount of added red - do blue and green matter for this function?

I agree, but now I’m curious about this. When I get back to work next week I’m going to throw a MELD light in the sphere and see what impact it has on the CRI value.

Argh, it pains me to know that your MELD S10 didn’t make the cut for EDC. The 488Hz PWM was too low for my liking as well, but unfortunately the SEPIC converter couldn’t handle being switched any faster. That was one of the biggest difficulties with trying to do primary and secondary cells - any switching converter that met the voltage and current requirements just wasn’t set up for good dimming. Hopefully MELD-X fixes all of that. The preliminary version of switchable PWM speed looks pretty good at 15.8kHz so far.

I’d love to see how that turns out. I’ve done tint mixing before, and sometimes it can turn out very nice. My wide-spectrum BST produces more vivid color than any other light I’ve ever used. It’s four shades of white though, not white and three narrow-band colors. It’ll be fascinating to see the results.

I think it was the 390nm version of this: http://r.ebay.com/O7nTU7

It’s a fantastic light, and definitely a jewel to hold onto for a long long time. It has all the fun exotic modes, and is only missing the boring stuff I use for EDC purposes. So for daily use I tend to grab either one of the many lights I made or something small and boring (like a stock Olight S Mini or L3 L10-219). The majority of my use is on low (~10 lm) or moon (~0.3 lm).

The MELD light still gets EDC’d a lot though, and is covered in scratches to prove it. It’s small and fun, so why not keep it in my purse in case I need it? I just use something else for general-purpose illumination.

… and it sounds like the new MELD drivers add that last missing bit. It should be about as close as one can get to a light which does everything. :slight_smile:

Being able to chose a color to mix in with white would be a good compromise. It doesn’t take much when mixed with neutral white but a bit more for cool white. For me

Neutral white 100, red 15, green 10, blue less than 5
Or
Cool white, red 20, green 10, no blue

Obviously this is very subjective and will very drastically depending on leds and current used.

I ran an experiment on the existing high-CRI mode that MELD has, which just mixes in a small amount of red, green, and blue (equal amounts [by power] of each). To my surprise it really did significantly improve the CRI. It appears that the effect is mostly due to boosting R9 by the addition of some red, so I suspect you could get the same CRI boost by adding red only, although this would change the CCT more than the existing method. Also, the DUV improvement is mostly luck - the white LED just happened to be high of the Black Body Line and was pulled closer by the addition of colors.

Standard High CRI mode enabled
LuminousFlux 134.5 146.1
RadiantFlux 0.4 0.5
CCT 5724 6070
ccx 0.3274 0.3206
ccy 0.3437 0.3334
DUV 0.00365 0.00156
CRI_Ra 70.3 79.9
CRI_R9 –29.9 15.1

It’s pretty interesting to see the added color peaks - blue slightly longer than the die in the white LED (royal blue vs blue), green on the short end of the green from the phosphor, and then red bumping it way up where the phosphor is deficient (in a cool white part). I’ll set it up for red only and see how that affects things.

On an unrelated note, the user-configurable high-speed PWM option is tested and ready to go, I just have to write it up and shoot a quick video demo.

:person_facepalming: I should have waited to place my order. Oh well, I’m hoping to order more soon anyway. It’s amazing the things you have accomplished with this firmware!

If that’s in reference to the high cri option - yours already has that feature! If you mean the high-speed pwm: you can always send a light or driver back to me for free updates.

I’ve updated the original post to add two new features:

The user can now choose between 1.9kHz and 15.6kHz PWM speed using an option in the menu. Choosing the higher speed gives up one bit of dimming resolution, slightly reduces the accuracy of the logarithmic dimming curve, and increases the microcontroller’s power draw from 1mA to 2.9mA.

MELD-X now support dual switches, which makes the user interface enormously more intuitive. Dual switches can be activated using an option in the menu. In dual switch mode, either switch can be used to enter commands or turn on and off, but ramping and min/max shortcuts will go a specific direction based on which switch is pressed. I just recently finished installing a MELD-X 22mm driver in a Nitecore EC11 with dual switches and it is awesome. I will do a writeup of how that mod was done soon as an example to help others set up dual switch lights.

Here is a demo video of the new features;

Both of these changes are to the momentary firmware version only, but the PWM speed option will be added to the clicky version within a few days.

I also have a version of the board that fits in a Nitecore EX11 (my EDC) in case anyone has one of those still.

Did I hear you say dual switch? Now your killin’ me! :money_mouth_face:
Ive always wondered why there are not more dual switch lights. Though there seems to be more now days.

I may add one of these to my next order. I have a lumintop sd mini coming and I may try to add another switch under the boot as I think someone else here might have done :wink:

I also have a version of the board that fits in a Nitecore EX11 (my EDC) in case anyone has one of those still.
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is that the one I traded you for your Romisen RC-C8?

UPDATE 1/7/2017: the user-configurable PWM speed option has been added to the clicky firmware as well. The UI user’s guide document has been updated to describe the new config menu option set.

Maybe, I’m not sure. That light is one of my favorites, I keep modding them up and then end up giving them away to friends so I end up buying most of the ones I can find these days.

In the OP, you said

Also, you’re only making drivers up to 24mm size. So, what if I wanted to put a MELD-X driver in something big, like a SRK, and use multiples of each LED color? I’d want to bump up the current on all the channels. Will the driver firmware be okay with that? Is there any chance you might eventually build a SRK-size driver with several regulators already on each channel?

It’s no problem to stack up more regulators on any of the channels, the firmware won’t care. I don’t currently have any plans to make a bigger version, but it’s possible. If I were doing a SRK build now, I would probably keep the stock board just for contact and put an 18mm MELD-X on top of it.

Sounds great! Thanks for the quick response!

Hey tterev3, I got one of your drivers up and running

Awesome, thanks for letting me know! How are you liking the UI? I hope you post more pics of your install, as far as I know you’re the first person to get one built up

Nice host choice!

Unfortunately I didn’t take pics during the build. I had to machine up new driver retaining rings (front and back of driver). The host is actually from the parts bin of a Chinese vendor (aka returned lights). Hence the mismatch anodising.

I’m already familiar with the UI as I bought a solarstorm T4 from Cereal Killer a while back (a BLF member I don’t see much now). The light was already modded with one of your drivers.

I don’t yet have a host for the other driver I bought.