Emisar D4V2 Flash Kit Instructions (Official How To)

I have a long “to-do” list already, but I may be able to whip up a batch file for this when I’m working on the OSX instructions (maybe a .sh for Mac as well). I hope to get to this tonight or tomorrow morning.

Any special requests/words of caution on the batch file?

I would put in some pauses and prompts like “Press any key to flash” and “did it work? Y or N (press ”N” to retry)” etc

Hank's ordering page has the option: "Special discount (-$10)". Are we allowed to check that box?

“For the D4V2 owers with the muggle issue (mainly for the orders shipped before July 19), please choose the $10 discount, and leave your order number. If you have purchased the D4V2 from our dealers, you will enjoy the discount as well”


I have some screenshots and some notes for the Mac/OSX portion of the guide. I’m shooting for submitting the guide here tomorrow (I have to build a fence first, so it might be pretty late before they go up if I even make it by tomorrow), but it may be Sunday before I get around to it. I didn’t get my D4V2 or programming key in time to use it as an example, but after you get everything installed flashing is basically identical to the Windows avrdude portion.

A bash/batch script might follow as well, but I’m not sure how to make it foolproof (as one would want for an easy mode script). I could make it so that if placed in a folder with a single .hex file, it would flash that file (or flash the newest file). It might be better to list all the .hex files in the same folder, and prompt to pick one by number. It has been a while, so I’m a bit rusty and it might take me a while to remember how to do that. Could be fun though.

I’d think it should also run the command to check connectivity (avrdude -p t1634 -c usbasp -n), then present a prompt like “Was that successful? Press ‘y’ to begin flashing or press ‘n’ to retry”

Another thought to make this more universal, maybe there is a way get it to ask which MCU (t13, t85, t1634, etc) is connected and then issue the correct command automatically… I don’t know avrdude that well though.

Any thoughts on this from the community? Personally, I’d rather just type everything in or copy/paste… but it seemed there was some interest in a script to simplify things.

How to flash on OSX:

1. Install Xcode from the Mac App Store (6.1GB install, so be ready for a long download)

2. Open Xcode and accept the agreement, wait for it to finish “Installing components”, and then close it.

3. Install homebrew (this is a package manager for OSX, for more info see https://brew.sh)

  • open Terminal and paste this into it:

  • press “Return” and follow the prompts.
  • The install will tell you what it is about to do, then you will be asked to enter your password. Do so and then press “Return”.
  • Once finished, it will return you to the prompt (computername:~ username$)

4. Use Homebrew to install avrdude.

  • In the Terminal window, type:

  • Homebrew will download and install the necessary dependencies, then install avrdude
  • Once finished, it will return to the prompt.
  • To test our installs, run avrdude. Type

at the prompt and press “Return”

  • the last line before the prompt should tell you the version of avrdude

5. Now we are ready to flash!

  • In the terminal window, type:
  • Press “Return”. This will take you to the “Downloads” folder.

From this point on, the process is the same as with the Windows version above.

I may come back and edit this with screenshots of the flashing process after I get my D4V2 and my programming key… but avrdude on Windows, Linux, and OSX is basically the same.

Thanks for doing this, I posted a link to this post in my second reserved post.

FYI new firmware binaries were released today: Index of /torches/fsm

Looks like the first 'muggle fix' firmware update was released on July 18th. I wonder what's different on these new files?

Changelog can be viewed here

OK, updated instructions with latest version.

Hi all, I'm new here on BLF hope I've posted this in the right place I've been following the Emisar D4V2, D4S and this thread for a while now. I've got a couple of D4 V1s' as well as the D4S I ordered from Hank at intl-outdoor.com last year. I'm really happy with all my Emisars. Hope someone can help me I want to flash Anduril to my D4S using the new D4V2 flashkit. I've been in contact with Hank earlier this week and he says it is possible to flash the D4S with this kit but the wires may need a bit of modding. I have no experience with soldering etc but he did send me an image with the wires connected to the D4S head. Please could someone let me know if I was to order the flashing kit from Hank, would it be fairly straight forward to connect to my D4S? if its fairly straight forward I'll take a chance and order it. I'm happy with the rest of the process using the info in the first post which is extremely clear but I'll tackle the specific command to flash the D4S if I end up ordering the kit. Sorry I'm not sure how to post the image of the kit connected to the D4S as I have it saved locally.!https://ibb.co/MN6QLcf! Thanks.!https://ibb.co/MN6QLcf!:https://ibb.co/MN6QLcf

I believe that you would just need some male to female Dupont jumper cables, such as in this set: 120 Stück 20cm Männlich zu Weiblich Weiblich zu Weiblich Männlich zu Männlich Farbige Steckbrücken Sale - Banggood Deutschland Mobile-arrival notice

No soldering required.

Firstly, welcome to the forum!

This is the image you were trying to show:

It didn’t work because you were linking to the page instead of the picture itself (click the “quote” button on my post to see how I did it).

For the D4S, you don’t need to solder anything (thankfully) as long as the USBasp that comes in the kit has removable wires between it and the pins (I’m thinking they will, but I don’t have one to verify).

You just need to get some Dupont wires (like these): Amazon.com
You need the female connector on one end to connect to the USBasp (thing with the USB port) and you could remove the connector at the other end and insert the wire directly into the programming holes on the D4S. No need to solder, just check the connection and then flash.

The only difference between the D4V2 and the D4S as far as avrdude is concerned will be that you replace “t1634” with “t85” in the command you type and of course the name of the file you are flashing (use the one for the D4S, not the D4V2). We’re happy to help answer additional questions as needed.

What are the minimum requirements for using the Android app? Any specific Android version? Can anyone recommend a cheap Android smartphone to use the flashlight kit with?

Hi kazibole & f0xx. Thanks for your quick replies I’m really tempted to order the kit from Hank but will hold off for a week or two and read about peoples experiences though you make it sound fairly straight forward with the Dupont wires. Thanks for mentioning the correct command for the D4S I’m used to working in Windows command prompt so should have no issues with the commands it was just connecting the kit to the D4S that was bothering me.

I’m hoping to become more active on BLF I got the flashlight bug after following the 18650 and 26650 review threads a couple of years a go and started out with an old 3AAA basic generic EDC light then moved to the Xtar Pilot II, then to a Wowtac A10 but it was the Emisar D4 thread that good me really hooked to BLF I spent days reading my way through the thread. I’ve been using a black D4 as my EDC with XPL-high 5000K for a year or so before ordering the D4S XPL-high 6500K exactly 1 year a go and have been using it as my primary EDC ever since and really loving the light. Both of my D4 V1 lights have the temp sensor issue where the reading is out by a big margin I had one which had accrurate readings but the leds died gradually but I just love the form factor of the D4S and the fact I get more runtime from using a good quality 26650 cell.

Once again, thanks for making me feel at home here.

Sounds like a good way to get started!

If you intend to update your D4’s (as in the plural of D4, not “D4S”), you may need an SOIC8 clip such as this one: Amazon.com

I don’t have this exact clip (the one I bought is listed as “currently unavailable”), but mine was about as cheap and works well enough for me. Banggood is another place where you can probably find it cheaper, but with slow Chinese shipping. I’ve heard that the Pomona branded clips are higher quality if that is desired.

You can put Anduril on them for more features if you wanted.

If your old D4’s have fried their emitters, it might be a good opportunity to start doing some mods (emitter swaps aren’t too bad). The Samsung LH351D in 5000k 90+cri is a favorite of mine.

I’m not sure if this applies to avrdude in Windows, but in Linux/Unix the command line is case sensitive. Just something to be aware of. If you fail a flash or the command doesn’t work, most of the time you can just adjust and try again.

My gray D4S is on the left, my green one is on the right.

Just another quick question please could anyone tell me if these 2 items from Ebay would let me flash Anduril to my D4S? I think the specs of the USBASP look fine for the D4S along with the Dupont wire. If both items seem fine I’ll order them as I’d love to have all the flashing modes to play with.

Sorry I’m completely new to firmware flashing but I’m both nervous and excited but willing to learn from the community.

USBASP programmer

I’m assuming the programmer will run at USB 5V but would like to confirm it will be fine for the D4S.

Dupont wire


They look fine yeah. My USBASP and DuPont leads arrived about a month ago, but like you I was a bit apprehensive to do it. I finally got round to reflashing my D4S on Thursday and it all went smoothly thanks to the brilliant walkthroughs on here! I just filed down the male side of 6 DuPont leads so that I could just push them in the holes of the D4S with a bit of resistance so they wouldn’t pop out again. I’ve now just ordered a SOIC8 clip so I can do my Q8!