TK's Emisar D4 review

dgq3, you’re probably right… spring compression can make a lot of difference in output, I see it all the time on the light box. The flat top 30Q should have better performance as it doesn’t have the added steel button top which has high resistance comparatively. You can see the internal resistance value of the cell on a charger like the Opus or MiBoxer C4-12. Edit: The manufacturer’s make these cells for battery packs, like in drills or such, and don’t put button tops or protection circuits on the cells. Aftermarket sellers add the button top or protection circuit, with a wide variety of issues associated therein. :wink: Sometimes these added button top plates are welded on nicely, sometimes not. Sometimes not at all, only being held in place by the insulation disc and the wrapper.

I just put a pair of Samsung 30T 21700 cells on my MiBoxer C4-12 and saw internal resistance values of 13 and 14. After testing with one and putting it back on the charger, it showed 9!

A question for D4 owners who own more or have tried more than 1 D4:

Ignoring heat, CRI, and throw, which LED between XP-L HI and 219C has the best tint, and why?

I have Nichia and XP-L 3A 5000k and the best tint with no doubt is Nichia, the tint is a relatively white but when illuminating shows very natural colors. The XPL-HI 3A is not a bad tint at all, but compared to the Nichia it loses.

The problem with the D4 Nichia (not so much in the D4S) is the heat, which makes that the stepdown constantly lower the power.

Optisolis-D4 mod.
EDC with 800lm of stabilised 99cri light)

probably will let the pics speak for themselves…

wall is about 18 meters away from flashlight,
camera set to “daylight” white balance

control shot:

D4 XPL-Hi “5D” 4000K

D4 219C 90CRI default 10622 optic

D4 219C 90CRI floody 10623 optic

Thank you Alex64, and d_t_a for your input and photos!

AEDe, the optisolis mod with buck boost driver looks amazing. I wish I had the skill to do that! Thank you for sharing.

It hard to get from gtranslation, but author choose more simple way. Boost driver with s2p2 led config. You can see there that mcpcb has bypass and cut to change config.

Is there any news that D4 on Hanks store will receive latest firmware (with configurable ceiling) ?

The black D4 has been sold out for some time on intl-outdoor, if Hank would have been in time making new ones his sales would be better (I do not see the black D4 ceasing to be popular any time soon, even with new models, the D4 is simply the best Emisar light). Does that maybe indicate that an upgrade D4 is in the make?

I don’t really know Hank’s plans. I fixed a stepped ramping bug though, and am going to send him an updated copy of RampingIOS V3 for each Emisar light.

The bug isn’t a serious one; it just acted weird when two ramp steps were exactly 128 levels apart and the step size happened to land exactly on the guess from imprecise integer math.

Anyway, I’ll send it but I can’t guarantee he’ll use it.

Can anyone tell me the screw size for the two screws that hold down the LED PCB? My aluminum D4 has flat head screws which allows for my 3D printed glow gasket to fit just fine. My D4 TI I just got has round head screws. Much too large to allow the 3D gasket to fit under the optic. I would like to get two flathead screws for my D4 TI.

My aluminum D4 has the round screws too, but the threads will be the same.

I could take one out and measure it tomorrow when I have my tools, but any fastener store worth its salt should be able to help you if you bring it in. They will be able to measure the length, diameter, and thread pitch, and if they don’t have it they should be able to tell you where to get them.

How come he decided not to sell the green and blue anymore, would u know TK ? i think the colors now are really boring even tho its a nice light we need more color options like before, even if price goes up let it be so…

Question:

Is the D4/D4S circuit diagram available anywhere?

I can probably figure it out myself (trained in college) once I open it to flash it, waiting for my soic clip, but before taking it apart I was wondering if there are any spare outputs on the AVR microcontroller.

You don’t need a circuit diagram to flash the part. You just need to be able to identify pin 1 on the IC, and how to wire up the flashing interface of your choice. I can’t answer the question definitively about spare pins, other than I know pin 1 is not used in circuit, in order to make it easier to flash. I suspect there is another unused pin, but my bare board is at work right now, otherwise I would inspect it to see. Based on the picture in this post, I believe pin 7 in unused. The picture should help you find pin 1 also.

Pin 7 is available.

On the D4, pin 3 is also available, and even has a solder pad connected to it. This was set aside to control aux LEDs or a button LED, but it wasn’t used. It is used on the D4S though.

I don’t know why Hank changed the colors available. I think he said the green was very difficult to get right though.

Does the fully-configurable beacon allow you to independently set on-time as well as repetition rate? The biggest complaint I have with my D4 beacon is that it is really just a “blinker”. A true beacon should have a very short on-time so that it can be full brightness yet still preserve battery life.

Nope, it’s 0.5s on, (N - 0.5)s off. But if you want to change the duty cycle, it should be very easy to do by changing one or two lines of code. It’s open-source.

It’s tempting, especially after reading through the 5K or so posts in this thread and seeing that many users are successfully modifying their code. But it would be a first effort for me, and I’m reluctant to risk one of my favorite toys in a learning exercise. And I remember someone (was it you?) may have mentioned that certain missteps result in an inoperable and unrecoverable (without special hardware) brick.

The D4S seems to be slightly more mod-friendly, and I’m already tempted to buy one of those. And I seem to remember reading someone’s (you again?) notion that maybe a beginner’s hardware/software programming kit could be offered as a turnkey “get started” package. I’m more likely to get my feet wet that way, then look at the D4 after gaining some confidence.

I haven’t managed to get any stores to carry a starter kit yet, but I still hope that can happen sometime. One of the main steps right now is finding a way to manufacture Lexel’s flashing key, and getting more brands to use it on their drivers.

However, it’d also be nice to have a kit based on a more common chip clip. (SOIC8 clip)