Eswitch should be easy to implement in code, hes using an ATiny and has pins that are unused which can drive indicator leds or an eswitch. This can easily be implemented in code quick and dirty without any changes to the design however Ideally, design should be edited to include pull up and pull down resistors for switch support. I donāt plan on doing this for my first run however I can mess with the code and add eswitch support, just solder your switch to v+ and a pin on the controller (micro will blow if above whatever the spec sheet says).
Internal pull up in ATtiny is good enough. Iāve never had issues with that. Hardware supports E-switch as parts are listed in BOM. Donāt know about firmware though.
When looking at BOM, it look like loneoceans already have on board resistor and cap for switch debounce in hardware already! But from his webpage it look like eswitch can be support but no firmware written for it yet.
It might be possible to do an e-switch right now by momentarily opening the power to the +vcc pin and making the attiny reboot. Maybe this is what he is doing and the resistor and capacitor heās added just debounce the switch.
As far as I know the code has not been released. Only the hex has been published and there is no way to modify it.
The good news is that he appears to be back working on this driver. His intention all along was to release the code when he was happy with it.
Itās probably best to sit tight for a couple weeks and give him time to finish what he is working on.
Thanks for the heads up, I saw that post after I put up mine and responded there too 
I just finished shoving the GXB172 modified for 12v operation in a Convoy S2+ with a XHP35.2 4000k from Arrow.
I got 2600 lumens on start up and drawing 17 amps or so my meter says. I like the beam much better than the xhp50.2 in the convoy.
Has a nice brightly defined hotspot. Much more throw for sure. Shinning both lights together it looks like the xhp35.2 just drowns the 50 out. But I know its only because the hotspot is so much more intense. I like it. 
How accurate do you think your 2600 lumen is? From what Iāve heard people say about the 35.2, it should not be much or any brighter than the older 35. The older 35, even with a very powerful driver, would not get to 2600 lumen OTF. This driver is not super powerful, like 3A+, it says it should be 2.5A. So overall I would not expect 2600 lumen, but maybe the 35.2 has a real improvement in output?
The HD bins go higher than HI so its possible iād bet
My lumen tube is calibrated to the set of maukka lights. So it should be close. I have looked over the test done on the xhp35HI several times, if you look at TAās test he hit 2710 lumen from a cold start, thatās the little ramp near the end of the graph pushed at 3 amps. I donāt think anyone has done a death test on the xhp.35.2 which Iām using in a highest bin in the datasheet E2. 590 lumens at 350 ma. TA hit 2710 with a xhp35HI and the HD would be even higher. Iām not absolutely sure of the results I got but Iām pretty confident itās close in the reading. The xhp50.2 in the same setup (6v) read I think the highest I saw was 3200 lumens at about 15 amps on the input side, still using the stock switch with two blue springs. Should do better with the LO fet switch. The xhp35.2 switch is stock with 20awg bypass.
On the driver 12v configured GXB172, using a .020 feedback resistor. I saw 3.2 amps from a power supply. I was worried the led may experience the blue tint shift at that current but I have not seen any blue yet. I was using a 30Q battery which will sag unlike the power supply.
If thatās an older test from TA then it was probably when his Lumen Tube was reading too high. Thatās also the raw led with no reflector or lens.
Are you saying you saw 2600 lumen at āturn onā with the driver modded to output 3.2A and it was powered from your bench psu and not a battery?
All those things do make a big difference. I typically ignore the first second or two and let the output settle for 15 to 30 seconds so itās more in line with the ANSI-FL1 specs.
I would be curious to see the complete light measured using a battery and after the output starts to settle. (Some lights settle after 10 to 15 seconds, some might need 30 seconds)
Itās awesome the led didnāt turn blue at 3.2A.
BTW, are you saying the psu drew 3.2A on the input side? That sounds way too low. A psu supplying power to the driver might need closer to 13-15A at 4.2v to output 3.2A at 16 or so volts, right? How did you measure the 3.2A? Iām a little confused.
30 dollars is quite a reasonable price for a couple of unique drivers. If there is a sale, then I will buy two drivers, one 17 mm one 20 mm.
The 3.2a was measured with my DMM in series with the xhp35.2 using the power supply to power the driver.
I can check the 15 second and 30 second readings if that helps.
The lumen reading was taken from the S2+ using a 30Q.
It be nice if we had some test data for the xhp.35.2.
I could do the test but then itās still a variable comparison between what the other established members have already done.
Itās hard to have a set standard if you have more than one standard. 
I re-read my other post, yeah I guess that was a little confusing. I wasnāt to clear with the description.
My fault JasonWW. 
Maybe I got it all sorted out now.
wow moderator007 this is crazy, I like it a lot! I cannot believe you manage to drive Gxb172 at 17A! This seem like pushing both driver and xhp35.2 to limit! Very impressive! I womder if there is any other driver (maybe 2S or 4s) to drive XHP35 to such high power 
. Your work result in even more power than this one: http://www.thrunite.com/tn42c-v2-rechargeable-led-searchlight/ expensive $270 flashlight 
I charged the 30Q up to 4.21v fully charged and saw 2800 lumens at 19 amps at the tail. This was measured using a 87V thatās only rated for 10 amps. I checked it more than once to make sure. It holds 19 amps for maybe a second or two then falls quickly to about 15 amps.
This driver is a Beast, doing the math 19a x 3.6v = 68 watts on the input side. Its only for a second or two, so its not of any real use but it will make Dale jealous.
Iāll have to do some more testing to see what the actual use numbers would be. I canāt test the high end on my power supply, because it only does 15 amps. I could up the voltage to give it enough input power but thatās not helpful in our use.
I donāt have an 87V, but testing high amperage in series with a DMM, with all of its additional resistance, is hard for me to trust. I tend to do all my amperage readings with a clamp style ammeter. Have you considered getting a inexpensive UNI-T UT210E or something similar?
I need one for sure JasonWW. Iām about spent out at the moment or Iād get one, maybe next week. I donāt hardly trust it either seems awful high. I do use my custom made gold plated banana plug soldered on 12AWG stranded wire about 6 inches long for the leads.
If you run the numbers based off the lumen reading say 16v x 3.2a = 51 watts out, thatās pretty much a guess but seems reasonable compared to the input side.
Iāll try to get a clamp meter next week to give a little more trust in the reading.
You got any recommendations on a reasonable priced clamp meter.
There is also possibility the current shunt inside of your multimeter actually heats up at such high current levels.
Meaning, if it gets hots enough to get higher resistance, the voltage drop will go up, and so will the current measurement.
The one I mentioned, UT210E, is about $30-$35 and is used by lots of people on BLF because of the big group buy here a few years ago. There may even be some valid coupon codes from Freeme or M4D M4X, but I bought mine in the US on ebay.
It seems like this models price is always going up. I think I paid about $28 a year ago, but the cheapest I see now is $36 with $40-$45 the average.
It normally comes with test leads and a nice zippered bag. It will auto turn off to keep from running down the battery, etcā¦
I only get this reading within the first second or two. From what I was reading on the 87V it has a .03v burden voltage for every 1 amp in the 10 amp range. According to that the reading is actual lower but heat would increase the reading if itās actualy heating up in that short amount of time. The 87V also comes with a 11 amp fuse and itās not blew yet. This is getting to technical for me, Iāll buy a clamp meter and find out if itās close. :+1:
I was checking that one out over at eevblog, seems of good quality and about right for my use. Ebay has a few for 45 in the us, so I may order from there to save the long shipping times. Thanks for the suggestions.
Fin17 has a code for the UT210E at Banggood that drops the price to 29.99. Archive topic - Banggood & Fin17
Iām not sure how accurate these things are, I can get four different readings on the same circuit by changing which way the meter faces and switching from the positive to negative lead.
I have tried using a milli-volt shunt on a buck driver, the noise drove it batty. Regular meter, true rms meter and every setting on my scope were all wrong measurements. The only way to get sensible numbers with the shunt was to use one of those one dollar led volt meters from Banggood.
If you can do it without shorting out the driver, maybe measuring voltage across the sense resistor and doing a bit of Ohmās law might give an accurate current.