TK, why don’t you just pull the MCU and flash it, then put it back on? I was told a neat trick to make removing the MCU easy, Put a big dollop of solder on the iron and apply it to all 4 legs at once on one side. It’ll heat up the legs quicker and the entire component will easily lift off within a couple of seconds. Surprisingly, when it comes off the legs are usually separate and clear of excess solder, it seems to go back to the iron.
I might, unless I can get it to talk to the usbasp otherwise.
… And I just got a hot-air solder station, which might help quite a bit. Haven’t even taken it out of the box yet.
Don’t have my scope to test pwm right now but here’s the relative output steps (fully charged 30Q)
- 0.1: 0.39
- 1: 3.31
- 10: 14.9
- 35: 46.6
- 100: 100
I got 2300Hz PWM on moon using a camera. With a 1/100s shutter speed 23 distinct patterns when moving it very fast across the frame.
A general request for anyone who has a new C8: Could you help me check the driver speed?
All you have to do is get a clock, put the light in biking mode, and then count the pulses like measuring someone’s heart rate. Like, count the pulses for 15 seconds and multiply the number times 4, or count for 30 seconds and multiply by 2. Then tell me the number.
It should be pretty close to one pulse per second. So if it’s 40 to 80 bpm, it’s probably normal. If it’s faster than 80 bpm, it’s probably overclocked. I think mine is doing about 110 bpm.
FWIW, the approximate driver speed in MHz is: BPM * 4 * 1.28 / 60. (or, pulses-per-minute times 1280 ms per pulse at 4.0 MHz, over 60 seconds per minute)
So, if you measure 110, that means about 9.4 MHz. A value of 40 would mean 3.4 MHz. The code assumes the chip runs somewhere near 4.0 MHz.
The bike flasher is definitely about twice per sec.
edit: exactly 120bpm.
Because I forget so much, I must seize the thought process when it hits… maukka can you say which tint bin is closest to pure white? I have been trending towards 3A , is there one that get’s me closer to pure white in your testing?
The variation is too big to make any conclusions. I’ve had great and not so great samples of 3A, 3B, 3C and 3D. But going by specs, I’d choose 3A or 3D. Even then you might not be able to avoid the horrid green. But I’ve also gotten 3B on the rosier side (assuming Banggood’s product pages were correct…)
Could just be my samples and variations thereof, but I liked 3D and 4A for “purest” white.
Appearancewise, I like 4A and 4D for white-white, the 5As for a little warmth.
Past a certain point, you just have to side-by-side compare them to notice anything. Anyone who’s played around with an audio equaliser of at least 10 bands (preferably 20) knows what I mean. Sometimes what you hear as “better” is just simply louder. 
This is really unfortunate.
My new Clear (Black) C8 is in the mail.
Can you please describe all possible implications of driver running twice faster than expected?
A few implications come to mind:
- The blinky modes blink faster
- Bike mode’s pulses look less intense
- The config mode has shorter windows in which to press the button
- The “buzz” for each config option looks less like a buzz and more like a steady low
- Changing mode groups takes half as long
- Moon mode is probably a bit more voltage-sensitive, but I haven’t tested how much
- The driver is basically guaranteed not to make an audible whine, since it’s oscillating too fast for humans to hear
- The light output should look extra-smooth with no visible pulses (except maybe in moon mode)
- LVP step-down should happen in half the time
- The lowest modes might be very slightly less efficient, maybe a few percent
Basically, for normal illumination purposes it doesn’t make much difference. But anything involving timing goes faster. A 25 Hz strobe is outside the ideal range for tactical purposes, and when the UI blinks out numbers they’re harder to count, and configuring the light requires faster reflexes.
Chances are, the factory can fix it by changing a single digit in a script somewhere. But I’ll be sure to send in other updates too, since these new drivers appear to have nicer 7135 chips than the old ones and I want to make sure everything is calibrated correctly.
Thanks, not a big deal to me then, since the configuration was easy enough.
Oh dang, I find the buzzes, voltage blinks and tap/long tap difference too fast/close as it was on Bistro (personal just me getting older 
)
Have a few drivers on the way.
So setup and forget about playing around then for me
Can we keep the 46% mode instead of 35% ?
I actually slowed that stuff down for this driver, because you’re not the only one who thought it was too fast…
… but then it doubled. D’oh.
Weird how much difference it can make to swap a single bit. The speed doubles by setting the low fuse to 0x76 instead of 0x75.
How unstable/unreliable is the Tiny13 overclocking? Is it unlikely to even work with most Tiny13’s or is it something we could make use of somehow? NOT for this driver, obviously. I’m thinking of new BLF driver designs (or actually firmware) that use the higher frequency on purpose.
It’s not unstable or unreliable. It’s within the tiny13’s spec and seems to work fine. However, the shorter pulses aren’t ideal.
The optimal PWM frequency is fast enough that you don’t see or hear it, but otherwise as slow as possible. So, right at the top of human hearing, about 20 kHz. At 4.8 MHz, the attiny13a gets pretty close (18 kHz), while running it at 9.6 MHz goes excessively fast (36 kHz). The faster speed also uses a bit more power and is a bit less efficient at producing light.
So, running it faster isn’t very useful for flashlight purposes.
Well better add some functions that requires computing to take advantage of the OC
I’ll get right on that.
The next version’s big selling point will be a mode which blinks out the digits of pi… all of them.
YES! Finally! Flashlights For Nerds™! :nerd_face: