Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

It seems that the Q8 project brought a lot of new members like me. Amazing work!

I saw it mentioned on Reddit quite a few times, and figured $40 can’t be bad for an introduction into the soup can thrower genre. I enjoy flashlights as much as the next guy on here, but spending a crapload of money on a Noctigon Meteor M43 to determine whether or not I would regularly use that type of light is extremely impractical.

See if press and hold or double click gets you strobe mode.

This will be the tasty soda that we probably drink in a long time :slight_smile:

Heheh nice words FlashMax!

Yeah BrianK you might just find a THIRD mode hidden under a long press, how awesome is that!

Sorry, yes, that`s the one I meant. Supfire M6.. got a little confused

That did it! Press and hold (longer) . :slight_smile: I was double clicking and got nothing but the 2 modes and off, and my long hold was too short probably by a nanosecond.

OK, question. Understand that I know little about the inner workings of these lights and there must be a very good reason this isn’t done. This SRK has 7 LEDS. Why don’t the designers allow for 7 light levels just by lighting LEDs 1-7 cumulatively? That would give 7 levels of output. Too much wiring? Would the beam pattern leave a lot to be desired?

Sorry, but even at my age I haven’t lost the childlike quality of always questioning. Too, it’s something to do while we’re waiting for Tom.

Heheh this was actually something I thought too
But then I learned a reason for more leds is higher efficiency for starters and that one needs a very complicated driver and wiring to do what you say.

Thanks. Makes sense now.

1) Output would be spatially uneven
2) Perceived brightness does not have a linear relationship with power
3) Going off what TheMiller said, there’s higher luminous efficacy when running multiple LEDs at a low current as opposed to one LED at max current

To individually control 7 LEDs, it would need 7 independent power channels controlled by 7 pins on the MCU… or a completely different design. The MCU only has 5 usable pins, which are currently used for:

  • 1x7135: Low modes
  • FET: Med/high modes
  • Indicator LED
  • E-switch

This leaves one, which often gets used for a 7x7135 channel for better medium modes. Or for measuring battery voltage. Or for another indicator LED color.

There are other reasons too:

  • What Miller said about efficiency. Using 1 amp spread evenly between 7 LEDs is more efficient than 1 amp sent to only 1 LED.
  • If it had 7 levels, at 1/2/3/4/5/6/7 amps, it would effectively only have a narrow range of medium/high modes. To achieve levels which appear evenly-spaced, the power use ends up rather uneven, like the graph of x**3 instead of a straight line.
  • Turning on/off individual LEDs in a 7x SRK would make the beam less symmetrical due to the overlapping reflectors.

If we have 1 free pin, why do we not have a 7x7135 channel? Firmware size limitations?

Put me on the list as well please, then I can junk my chinese knockoff SRK.

I’m not actually involved in the project, so I don’t have the details. If I understand correctly though, it’s because:

  • There wasn’t a free pin until recently. (or there may not be a free pin even now?)
  • Three-channel drivers weren’t supported by any firmware when the driver was created.
  • Ramping is generally less smooth and more fiddly with more channels.
  • It’s too late to change the driver.
  • The extra parts could raise the price.
  • Diminishing returns; going from 2 channels to 3 is a smaller upgrade than going from 1 to 2.

Basically, the extra complexity probably isn’t worth it right now.

Hmm well I think Narsil has grown a lot the last year
Now Tom has made a Narsil version for 1*7135/7*7135/FET drivers
Solid triple channel drivers like TA drivers are the result of combining PD68s trple channel drivers and DELs input on stability and parts for the Q8 driver.
NOW at the start of a FET based driver light triple channel is obvious, hence this is planned in the FW3A :slight_smile:
When the Q8 was started people were very happy with the Kronos X5/X6 drivers with FET + 1 so it was the logical choice at that time.

Ehm wait the led in the switch uses a pin too right?

Yup, one pin for the e-switch, one pin for the indicator LED. Unless the indicator is more than one pin, like if it does more than one color. I forget. IIRC it was just one color, and there were no free pins until the recent switch to using VCC for measuring voltage. If I didn’t imagine that. I remember all sorts of things which didn’t actually happen.

early onset prescience, don’t fight it :wink:

The Attiny85 has 8 I/O pins:

  • reset
  • Grnd
  • VCC
  • 5 I/O pins

I had 2 different code baselines: Narsil (2 chans) and Narsil Triple (3 chans). It's now recently has been combined into one code base I'm calling "NarsilM" for multi-channel support. These two versions were diverging and getting difficult to keep both up to date.

Your hardware can be specified at compile time.

For an SRK, yes, we can do 3 channels, a switch and a indicator LED (battery voltage monitoring can be done internally). But for 2S uses (like XHP50's or XHP70's), we need external battery voltage monitoring, so need another pin - an "LDO" must be used to reduce parasitic drain. Right now, the indicator LED is sacrificed.

So NarsilM can support it all, accept for the combo of 3 channels, LDO, and an indicator LED. Bad news is for 3 channels, it's very close to the limit of program space. I haven't released NarsilM yet because of needing further testing of all the configurations, and it would help to do some optimizing to reduce the code size.

Back a year ago, yes - 2 channel was the way to go. Not sure, but think 3 channels was just coming out, maybe not fully supported yet. We committed early to the electronics design though.

Looking at the logs, the first released 3-channel code (that I’m aware of) happened about 6 weeks after the Q8 project started. I didn’t merge it into the stable branch until another 4 months later. So, yeah, it didn’t really exist as an option at the time.