Very nice info, thanks for the review! 
A fan blowing on the light.
This is very interesting. A lot of work, I guess. Thank you for this useful information!
How did you measure PWM?
great job maukka!
I measure PWM with an oscilloscope and a photosensor. Since I didn’t have time to do it with the S41, I just inserted the Astrolux S1 numbers I did earlier in to the table. I’ll verify this soon.
The numbers seem rather low though, frequency should be 18 - 19kHz with this driver. The med2 value looks like a copy/paste error, according to Toykeepers code all modes except lowest one should run with fast pwm with the frequency mentioned above .
Excellent review
+1
Excellent review with new/unique style.!
Ok, thanks for the heads up. I’ll double check the pwm.
Out of curiosity I checked the pwm frequency of a ATtiny13a sitting on my breadboard, and my old DMM says 15 kHz. Can’t use my oscilloscope for double check, it is even older, analog and totally de-calibrated. Attiny datasheet says the internal clock oscillator calibration has been done in factory - but not very accurate I guess …
maukka, two thumbs up for your detailed review!! :+1: :student:
Thanks for that!
To get the specified clock tolerance you have to use the default internal oscillator (9.6 MHz for the tiny13). The calibration factor for the other oscillator is there, but you have to apply it manually in firmware. Look for the OSCCAL register.
Very nice review!
Thanks!
Great! I read through with interest.
edit: just wondering, did you see readings from initial flash lumens when power ON?
Over 1K lumens @30sec aint bad for this size of light anyway :sunglasses:
Ah, that’s interesting. I just fused the ATtiny mentioned above to 9.6 Mhz and the pwm frequency reading is now very accurate. I guess I can’t read the calibration value from Attiny program code?
Great review! Thanks.
I love this tiny high cri quad copper head!
Yes, the turbo lumens at power on are in one of the runtime graphs:
For the 18650, the numbers are 1364 lumens at 0 sec and 1175 lm at 30 sec.
That’s professional maukka! Thanks you!
Wow! Really awesome info. Thanks for all the effort you put into this.