BLF GT official support thread [FAQ updated 11 Jan 2018]

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Thank you
:wink: :+1: :+1:

Got mine today. My switch LEDs are different brightness levels like someone mentioned before. Not sure if it bothers me though. Anyone else have the same issue?

FAQ: How can I get a BLF GT?

  • Post in the main GT thread saying that you want one (or more). Then wait for a private message with further instructions. It may take a few weeks before you can make the purchase, because production is slow.

FAQ: Can I get more throw if I drive the emitter harder?

  • No, not really. It’s already driven at 2.5A, which is just shy of the peak for the GT’s emitter. There’s very little to be gained from giving it more power; it’ll mostly just produce more heat.

FAQ: Why is my lux meter showing me less than 1.2 Mcd for the GT?

  • Could be caused by several things…
    • Lux meters usually read higher for cool white lights, so the GT’s warmer tint could be tricking the meter. This doesn’t mean it won’t throw as well as intended, just that the meter isn’t very good as measuring it.
    • The beam doesn’t fully collimate until ~20+ meters, so it may be necessary to increase the distance between the light and the meter for a good measurement.
    • The light might be running at 2.0A instead of 2.5A. Be sure to take measurements on turbo (which is above the normal output modes; double-click to access turbo).

FAQ: How can I mod it to increase throw?

  • Try an Oslon Black Flat for maximum throw. The hotspot will be tiny though, and the driver may need to be replaced or modified (TBD).

FAQ: How can I mod it to increase lumens?

  • Try a 12V XHP50, XHP50.2, XHP70, or XHP70.2. It will decrease throw though, and the driver’s sense resistor should be changed to increase power to ~5A. Bigger hotspot, more lumens, less lux. Texas_Ace tried it and says the result is nice. Using 8 cells is strongly recommended for this.

FAQ: My tailcap ring doesn’t want to spin. Help?

  • There may be a pinched or insufficiently-lubed O-ring inside. If you remove the Lumintop sticker inside the tailcap, the parts should unscrew (reverse-threaded), and then you should be able to check and lube the O-rings.

Thanks TK! Done and done into post 4.

There’s another question I’ve been asked a few times, but it’d probably be out of place in the main list…

FAQ: When will other firmware be available?

  • As soon as I get a GT. I have no idea when that will be, but it should only take a few hours after I get hardware to test on.

Google Translate does not translate PDF files
Any solution for non-English speakers?

EDIT

Solved. … BLF GT official support thread [FAQ updated 11 Jan 2018] - #5 by Team-Giggles
Thank you very much.

Please see if post 5 is useful. (Still need to somehow add the various tables to it.)

Either I have the wrong switch cover, or my LEDs are so dim that you can’t tell they’re working unless you’re in a dark room or at night, but I’m beginning to think it’s the LEDs

Hopefully TA can chime in, most of the team lights shipped with opaque button boots.

It is supposed to be very dim, as mentioned in the FAQ above. Two Three ways to have it brighter:

  • Change the boot to a clear one. The boot is 12 mm, not a common size unfortunately.
  • Change or stack the resistor controlling the back-light current (R8). Stock value is 33k for ~100 μA. Change to 15k or stack another 33k on top of the stock resistor to double the current. The resistor should be 0603 footprint, but a 0805 will fit as well. Note that this will take the parasitic drain from ~240 to ~340 μA.
  • Rewire the button LEDs in series and drop R8 accordingly.

Edit: For the mismatched LEDs, that can happen with LEDs wired in parallel. Still preferable to having one off-center LED I guess. It may also simply be the way the rubber boot is orientated. A simple hack here would be to rewire the LEDs in series and change R8 to 10k (MCU is running at 5 V on GT, so there is enough voltage to do this). Bonus, double brightness for same parasitic drain.

In post 5, specifications, emitter, could we add the details that it is a D4 bin and 4,000k color temp?

Also, I have been asked if the strobe modes are using the 2A, 2,000 lumen mode or the turbo 2.5A, 2,500 lumen mode. Does anyone know?

It seems a handful of black boot slipped through to normal people as well. Neal is taking care of them on a case by case basis.

You are also spot on with the rest of the details.

Post 5 is a verbatim copy of the printed manual so it should stay as is. No problem to add the bin info to the FAQ though.

For the strobes, these are at 2.5 A. This is from the source code:

void Strobe(byte ontime, byte offtime)
{
    FET_PWM_LVL = 255;
#ifdef GT_BUCK
    ONE7135_PWM_LVL = 255;  //  for GT-buck
    _delay_ms(ontime);
    ONE7135_PWM_LVL = 0;        //  for GT-buck
#else   
    _delay_ms(ontime);
    FET_PWM_LVL = 0;
#endif
    _delay_ms(offtime);
}

Basically the buck chip is set to full power in the first line and then alternatively enabled/disabled in the next three lines.

Is there a way to have the lighted switch stay on when the light is turned on? Having a lighted switch is just as helpful when you want to change output levels or turn the thing off as it is when you want to turn it on.

There’s no option for that. You’d have to manually run a new wire to keep it powered all the time, so you’d lose the “indicator” function. No big deal as I have two lights where the switch stays on all the time.

If the GT’s lighted switch is controlled by the MCU, it should be possible to change its behavior via firmware. From the way the question is written though, I get the impression that maybe that’s not how the switch light works on this model?

I thought it worked like the Q8, but now I’m not sure.

Yes it can be changed by firmware, but not the existing firmware as it has no options to make the light always stay on. I think Tom E said he was going to possibly add the option to make the light always stay on in a future version of NarsilM.

For me this would be great. I just came in after using the GT and with the temperature around –10F and I was wearing gloves which made locating the switch by feel was impossible. I had to take my glove off to find the switch, kinda cold on bare fingers holding an aluminum light.

You could wait a while and see if it gets done then reflash the driver. Personally I would just pop the driver out and move a wire. You could do that now. I haven’t looked to see if a resistor will be needed or not. I plan to swap the leds and switch cover so I’ll write up all that info for anyone else.

The switch control code is already written. I mostly just need to adjust the ramp values to work on the GT’s driver, and check the calibration in general. I doubt it’ll take long. I could probably even do it without hardware, but I make no guarantees that it’ll actually work.

The method I’ve been using to control the switch light is:

  • When the light is in any operating mode, the switch light copies the main emitter. The button light stays on steady in regular modes, blinks in blinky modes, etc. Button brightness also imitates the main emitter, though it only has three states — off, low, high.
  • While in the “off” state, the button goes to the user’s configured brightness — off, low, or high.
  • While in the “lockout” state, the button goes to the user’s configured lockout brightness — off, low, or high.

It seems to work well on the Q8, but I hear the GT’s boot is a lot darker so I’m not sure the “low” brightness will be of any use.

This sounds great! The thought of me “going in” with a solder iron and changing things feels like a recipe for disaster to me. What is involved in “re-flashing” the driver? I know my way around the numbers concerning lights, led’s and batteries, but I am a total noob when it comes to drivers and all of the other internal electronics you guys talk about that make my eyes glass over.