TK's Emisar D4V2 review

The rainbow mode was originally 0.5s per frame, but people thought that was too fast so I changed it to 2s per frame. However, while finishing up the KR4 firmware, Hank asked me to change it back to the faster speed. Not sure why, but I’m guessing because it’s more eye-catching.

There’s a setting in the config file which can set the speed per config. Use one of these lines:

#define RGB_RAINBOW_SPEED 0x03  // 0.5s per color
#define RGB_RAINBOW_SPEED 0x07  // 1s per color
#define RGB_RAINBOW_SPEED 0x0f  // 2s per color

Thanks TK. Is there a thread on how to compile my own hex? I don’t think I’ve seen one yet. I prefer the 2s frame.

Great, thanks!

There are a few, depending on which tools you want to use. If you’re using Windows, I’d suggest installing WSL (Windows Subsystem for Linux) with Debian or Ubuntu inside, and then following the README file in the firmware repository. Basically, run a few commands to install the tools and download the code, then go into the anduril directory and run “make”.

Some of the tutorial threads are also linked from the README file, but I’m not sure if it’s up to date with the latest info from BLF.

Been away from the forum for half a year, renovating a new house we bought. Back a day and already ordered a ti d4v2. Good to be back :person_facepalming:

Thanks TK didn’t know you can do that, installed amtel studio and loaded up the repository but couldn’t get it to make anything. Will try with the WSL route.

I got and posted a full Atmel Studio version of Anduril - didn't take too long to port, for me that is. But now, it's my custom branch of the December version, so not current.

I would guess that the laptop cells don’t permit a high enough amp draw for the LED to reach max output (in both light and heat), which would allow it to maintain steady output without thermal stepdown. Your eyes may never know what they’re missing, though, since they tend to adjust. Just don’t buy another D4V2 and run a high-amp cell in it, side by side with the first one, or you might be spoiled…. for ten seconds or so. :slight_smile:

Someone should experiment to see if there’s a particular step we can select as our top output (at, say, 72 degrees ambient, handheld) which would prevent thermal stepdown.

The default was originally 500ms on, but that seemed too long so it was changed to 100ms.

There’s plenty of room to add more stuff in the attiny1634 versions, but on attiny85 the ROM is already full. So I’ve been avoiding adding much. However, the beacon time is relatively simple to change in the source code. Look for “beacon_mode_iter()” and change both instances of “100” to a different value.

Is there a way to turn the switch light off on the ti version?

You can disable it in the code and then reflash the firmware.

Thanks I might do that when mine arrives. Feels a bit to much.

It actually does step down on Turbo starting gradually at about 20 seconds, and severely at about 30 seconds. Even Level 6 steps down eventually. I think these cells must be delivering much more than 4.4A. It may not be good for them, but I have 9 of them, and they were free, and I rarely use the brightest modes, so I’m not worried about it. They don’t get hot, even after 5 minutes on Turbo or 20 minutes on Level 7, so I don’t think there is any danger of violent failure.

I knew I wasn’t going to get the full potential out of this light with these cells, and since I don’t need ultra-brightness from it (except to show off), I’m ok with that. It would be fun to see what a 15A cell could do, though.

Step 5 of Stepped Mode was the highest step that did not require thermal throttling at room temperature, but you’re probably talking about fine-tuning the ramping max using the 255 possible increments. I was also not holding the light for that test. Step 6, handheld, and with about a 50° thermal limit, did not step down. It got fairly hot, but not painfully so. Somewhere between those two steps, then, would be what you’d want if you want to keep the default 45° limit. This is all using the SST-20 4000k emitter, though.

Max discharge spec means max of 4.4A safely. In this light it should be much higher and beyond what's considered safe by the battery manufacturer.

That makes sense. Thanks. In a related matter, is it safe to use an extremely high-amp cell in these flashlights, such as 35A? Would the flashlight throw all 35 amps into the emitters and possibly damage them before thermal throttling could turn them down? I ask because a friend of mine offered to lend me one, but I was afraid to try it. Some (non-authoritative) sources say it could cause damage, but I think those might have been referring to other flashlights.

Well, it's 35A rated - that's not a real 35 amps. Ok, battery ratings are one thing, good to know, but not what you will get. Actual amps you get is controlled by the circuit. These flashlights use FET's with little to no restrictions imposed, so better cells get more amps, but to a limit. There's lots of resistances that add up to restrict the flow of amps, including the resistance of the battery itself.

The true amps you get on a fully charged 35A rated cell may be 15 amps or so, maybe possibly up to 20 amps, but that's at the best. As the cell drains, which is will drain fast when drawing 15-20 amps, the voltage drops, resistance goes up, resulting in lower amps. This assumes on max/turbo setting, not lower settings.

In general, it should be fine with high-amp cells like the VTC5A. However, turbo on a fully-charged cell will get very hot very quickly, and it’s not very useful for anything beyond the “wow factor”. So I’d suggest using more moderate cells like the 35E. Or the 30Q is a popular compromise between the two, still pretty high in amps but not quite as crazy as a VTC5A.

However, if you have a 219C model, I wouldn’t suggest using high-amp cells. That’s known to be a bad combo which can kill the LEDs, so the 219C models ship with a lower turbo level. Even then though, probably not a great idea. Also should probably avoid the really high-amp cells with high-CRI SST-20.

With laptop pulls and random cells though, the main risk is the opposite… damaging the battery. Cheap cells usually can’t handle many amps, so they’ll have a pretty short life span when used at turbo.

One way to avoid all these issues is to use a KR4 with the no-FET firmware. It’s regulated up to 5 amps, which is less impressive but still more than sufficient for a light its size.

Been eyeing these alittle while now, just so many cool features to these.

The colored leds, am I seeing those runtimes right?
That on low, you could basically leave it on a color, as a locator light so you can find the flashlight in the dark, and ,well, just to look cool, and its pulling virtually no significant power?
On low, is it only visible in the dark, or in a room with lights on also?
On high, do they offer any significant output? Or still just for looks?
For example, could I use them as a small amount of accent color lighting when taking a photo of something?

The UI looks decent, but there is so much to it, cant get it all in my head with just the diagram, is there a good video showing the UI?

To answer some of my own questions, found this video.

So the colored lights get bright enough to see in a lit room, and to read by in the dark,
but not bright enough to actually cast any color on a subject when taking photos in a lit room.
Oh well, still a really cool feature.