Received my kit yesterday. Reflashed my D4v2 via the Android and OTG method. Couldn’t be easier!
Now what else can I do with this kit? 
Done.
If I can do it (my old eyes needed a magnifying glass), everyone can. Thanks to TK & Hank for resolving the issue.
Now comes the really difficult part … getting my old preferences back into the light.
Kit arrived yesterday and update done to my D4V2 the same day from MacOS. As other oldies have noted, the hardest part is seeing close up to ensure the tiny pins are in place on the pads.
It might help to have a second via cut in the board to position the pins better. That could be done in future without affecting backwards compatability.
The quick reset now in Anduril is great, too. The reset cleaned up a small issue seen after flashing a Q8, where I presume some old configuration data wasn’t cleaned out by flashing.
Thanks to Hank and TK for sorting this - and incidentally for the great leap forward in firmware flashing.
I flashed my two D4v2s this morning without problem; the pogos neutralized my tremor. Thanks Terry for your clear instructions. Thanks TK and Hank for addressing the problem promptly and efficiently.
Also got my reflashing kit ordered from Hank, tested on my D4v2 and at first try, it didn’t succeed, most likely due to the pins not aligning properly with the D4v2 holes (they’re very tiny and my eyesight is a bit poor…) A second try worked successfully. (I have previous experience flashing the BLF/Sofirn Q8 into NarsilM v1.2 and Anduril already, so I sort of knew how the AVRDUDE works on PC… The flashing process seems to take just a little bit longer, maybe by a few seconds, on the D4v2 compared to the Q8, but it could just be my imagination)…
Regarding the 2019-08-05 hex file, aside from eliminating the muggle mode bug, adding a factory reset function, are there any other minor new functions added or changes in behavior (eg. thermal behavior or say candle mode behavior), compared to the June 2019 firmware?
here are some updates listed:
I am really happy that the Android phone method worked so well for many people and they are now happy D4V2 users.
Soon I will get my D4V2 too 
brewster, I also want to thank you for those Mac OS X instructions. Was super easy and it worked perfectly with my Mac Mini running OS X v10.13.6. And a thank you to the OP for the rest of the detailed instructions on using AVRDUDE, and also a thank you to Hank for sending out a warning, and then making those flashing kits available at a good price!
I now have an updated (and slightly safer) D4v2! What an awesome light it is…
Well, I received the flash kit shebang from Hank today. I will try it tomorrow using Mac OS and, though I’m not very handy tech-wise, I will hope for the best. I’d try now, but I am a few too many sheets to the wind.
I just got home from a trip to find my kit waiting for me. It just took me a few minutes to flash both of my D4V2 lights.
Thanks to everyone who contributed to making this possible. Between the provided hardware and the excellent instructions the process was smooth.
For those who have already done some flashing, I should mention that I used the USB device, driver, and software that I already had. I just attached the new cable and followed the instructions without any modification.
Flashkit arrived a week or so ago, Flashed using the phone app instructions and that was it, simple and easy.
used the firmware listed here https://intl-outdoor.com/emisar-d4v2-reflashing-kits-p-941.html
is there a website/list of cmpatable firmwares, as it seems a shame to leave the flashing device sat idle in its bag
i got my flash kit today
and i get the following error
avrdude: AVR Part “t1634” not found.
i had no issues previously flashing my blf q8 or my d4s or fw3a
What version of AVRDude are you using?
Try getting the latest AVRDude v6.3
I had an old version of AVRDude installed…
Installed new version…still didn’t work…had to actually UNINSTALL the old version and reboot computer before old version stopped interfering with new version. (win10 computer here)
Then the new version (6.3) would work.
That's pretty much what happened to me here.
Also, CoRDS, look at the very last part of my instructions under "problem/solution", this worked for someone on reddit.
I believe the previous posts recommending you upgrade to the latest version of avrdude are correct, and doing so should resolve your issue.
Depending on your OS and method of install, the method to upgrade avrdude will be different. If you run into trouble, make sure you provide these details and we’ll be happy to help.
It seems the flashing pads on the updated D4SV2 have vias cut at both ends of the row of four pins. See the second photo at
That will greatly assist many folk in locating the pogo pins. The modification must have been in the works already, before my suggestion.
Well, I’ve tried to flash my D4V2 using my Macbook, but no cigar. I suspect I’m losing my way with AVRDUDE, etc. (I’m crap with programming of any kind), plus my eyesight is poor… maybe I’m not getting the pins aligned properly. So I’m wondering whether anyone might be willing to flash it for me… I can even send the flash thingy I received from Hank if anyone wants one. I will pay for postage, too. If anyone in the U.S. can help, please PM me. Thanks! (I’m in New Orleans, if that matters.)
I’d be willing to do it…
do you have an android phone?
Should try it a few times…holding the pins steady…maybe you can use some tape to hold it in place?
I’ve successfully flashed a few of my lights
No Android phone… iPhone. (I’m originally from WI, by the way.)