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.
I verified the light pwm. The pwm frequency is 17,2 kHz on all modes other than moonlight which is 8,6 kHz. Thanks for your tip!
Thanks
Ah 
Very nice for the start :partying_face:
Excellent info. Thank you maukka :THUMBS-UP:
Awesome review! I was searching for over discharge protection and your review answered my question!
Just purchased a pair of Samsung 30Q cells for this light i received yesterday, was wondering if anybody is using this battery along S41? Read on some post that 30Q provides too much Amp for this light and it will over heat very quickly. Any chance of the 30Q damaging it?
I read this at least 10 times. Thank you for your excellent reviews. How many amps is it pulling with 18350, and how many with 18650?
Does anyone know if the S41 has fixed the green tint leds, and the shorting problems?
I am new here. Great review above, I ordered one based off the recommendations. I have one issue with mine, my 18650’s were dead and all I had was the extender tube and two 18350’s so i inserted them and I am afraid I murdered my light… Is there any way of repairing the over voltage the light had from my neglect and lack of knowledge? Or should I cut my losses and just order a new one. It was the nichia version. Thanks in advance!!!
you can buy a replacement driver here
but firtst check if the LEDs are still intact
http://www.mtnelectronics.com/index.php?route=product/product&path=60_94&product_id=740
you can use a 18650 cell and connect it directly to the LED board to see if ther LEDs are fried or not
Thanks for the info!!! I will test the components and see what need to be ordered!
I deeply enjoy reading your reviews. Thanks for this one also.
Great review. I use the same batteries in mine and I couldn’t be happier with the tint and performance.
Bob