On the graphs there, I see a small dip in the PWM each cycle on the highest mode. The qlite runs in fast PWM mode though, which Iāve had a suspicion might do that. Just like it always turns on a little bit even when the value is zero, I had heard that it might not stay fully on in turbo. Itās hardwired to turn on at the beginning of each cycle and turn off at the end.
However, I think phase-correct PWM is better about that. It never turns on at zero, and I think at the other end it also never turns off when the value is 255. We could probably verify by measuring lumens on fast PWM=255 vs phase-correct PWM=255, but Iām not sure how big the difference would be.
Yes, Qlite is never 100% on because they must have used inverted PWM, meaning inverted output values...
0 = On
255 = Off
From the datasheet...
With fast PWM, a 0 PWM_LVL (OCR0A) means it is never fully turned off (there's 1 blip of being on out of 255 clock cycles). In Qlite's inverted PWM case, 0 meaning max output, it means it's never fully on, but it can be fully off. We are using non-inverted PWM, so it can be fully on, but it can't be fully off. This is taken care of with putting the driver to sleep so we don't allow the light to run with PWM_LVL = 0 (except as you noted ToyKeeper, it happens when you hold the button to move to the off mode, as long as you hold the button it will sit in this state). I believe this should only happen when the mode order is H-L, correct?
I took your advice and updated the 255 mode to be PHASE. I can't test it because I don't have a FET driver, but you already said it works. I could have also been done by changing the code so that it forces PHASE whenever PWM_LVL is 0, but this is an easier fix.
That's for the Qlite, not this firmware. I should bust out my nifty little pocket oscilloscope if I can remember how to use it. As I noted above it should be 100% on.
It happens at either end of the scale (and with either mode order), but itās really hard to see after turbo unless the button stays pressed for quite a while. Regardless, using PHASE on both ends eliminates the issue.
I normally set PHASE as the default anyway though, and override it only for specific solid modes. This lets me turn the emitter off entirely during strobes and such, without having to mess with special zero-handling all the time.
BTW, I added a very simple firmware to help with calibrating voltage readings. Itās ToyKeeper/battcheck/*.
All it does is read out the raw attiny voltage value. When connected to power itāll briefly blink once, then itāll take several voltage readings (without load), then blink out the value one digit at a time. So, for 183 it would blink once, pause, blink eight times, pause, then blink three times. Wait a few seconds, and the cycle repeats with a new reading. Itāll keep doing this until power is disconnected.
Itās useful only for calibration. Measure a battery in a DMM, put it into the light to get an attiny reading, let it run a few times to get an average, then write it down for later reference.
So far Iāve only tried it on two drivers, and they get nearly identical values. One was a Ferrero Rocher (similar to BLF17DD) and the other was an AK-47 (one-sided nanjg variant).
I did something similar but took values under load and wrote them to memory every 5 seconds. A long press reads out the latest stored value in a similar blinking fashion. Useful for checking voltage state under load.
This is amazing. Iām busy for some weeks - heavy workload and some truly desired holiday - and everythingās different.
I feel like a toddler who is trying to keep up with a bunch of 5y-oldsā¦ he doesnāt stand a chance, but he truly has fun.
On Nov 14th I downloaded what was supposed to be Star Offtime 1.3 (dont remember the source) but that one hadnāt the DualPWM parts.
Now I downloaded StarOfftime from JonnyCās GitHub page (titled version 1.2 but changelog to 1.3) and #wham# major change.
I very much like the idea to use at least two different outputs, but there are some code changes coming with it, that I donāt understand. I hadnāt fathomed all of the previous code - only the parts I needed to adapt - but now Iām lost at some crucial parts. I already see that what I want to do (using one 7135 at 255-PWM as medium mode) will come into conflict with the DualPWMStart threshold, as I need full PWM in the ALT_PWM_LVL signal path. It seems the Voltage Monitor, who uses the ALT_PWM_LVL, might get a hickup tooā¦
But before I start asking questions that are already answered:
Are the software changes to dualPWM discussed anywhere? I just scanned the last 400 posts of this thread - as well as some of wightās driver threads - but the FAST_PWM_START / DUAL_PWM_START / ALT_PWM_LVL changes to the code either came completely out of the blue, or I missed it, or they are discussed elsewhere.
Iād be very happy if you could give me a heads up - or if I may ask one or the other question about the code in this thread, when Iām stuckā¦
Thanks a lot.
There was a version numbering reset when Dual-PWM was forked from the main code for development. Later when Dual-PWM became fit to replace the mainline firmware the version numbering was kept.
IIRC there was never an in-depth public discussion of the new firmware and itās features. Of course itās actually at least two firmwares: momentary and offtime. The two major features added to offtime are: A. the ability to change from FastPWM to Phase Correct below a certain threshold. B. the ability to use two PWM outputs simultaneously and revert to only one of them below a certain threshold.
As you may now imagine, those features are aimed squarely at moon mode performance. It would be simple to make small but heavy-handed changes to the current offtime firmware to allow for turning off the main PWM and putting the alt PWM at 255/255 for medium. Unfortunately I havenāt envisioned a simple way to implement these changes so that they interface nicely with STAR_off_timeās other features (like low voltage stepdown).
Ah, I see. All went on behind closed doors
But I like the result for sure, so thanks nevertheless.
If I only look at the Offtime branch: all started with the nice, configurable and documented STAR firmware which was the first that included low voltage shutdown, then came the off time cap, turbo ramp down, dual threshold for the reverse clicky, now dual PWM modes (fast/PhC) and ALT PWM output channels (PB1/PB0)ā¦ this makes a great deal of options for a Nanjg and all the custom driver boards.
I know the STAR firmwares are great just because they are highly configurable with little knowledge. This is what makes them so good and everyone else is writing own code anywayā¦
Does this have a benefit only for the FET drivers, or for 7135 drivers as well? Like getting even lower moon or getting rid of the dreaded losing-moon-when-the-driver-is-hot problem?
Thx again
Thatās thanks to RMM and JonnyC, they cooked this up. RMM posts about the motivation over here: (#1447) Oshpark Projects
I havenāt played around with it. I donāt think that it will help at all with that problem. Thatās really part of what the dual PWM output is intended to help with I think.
I should have at least one driver soon with dual PWM, and am planning to add the ability to control PWM for each channel for each mode. This should enable things like 1x7135 at full power for a more efficient medium mode, and stable moon/low/med on 7135 while still keeping high/turbo on a more-powerful FET.
For drivers with 8x7135 (one split off for moon), it could still use all 8 for the highest mode, but should be able to use just 1 for the lowest few modes.
Richard flew only a select few of us out to his compound to have a discussion, complete with cigars and strippers. Actually Richard came up with this idea, asked if I could do it, so I just added it.
I haven't done any testing to see if you can get lower lows on 7135's with phase correct and if they are consistent across variations of 7135's, but I do know you can use lower values to get the same output compared to fast PWM. To be honest I don't do any tweaking of moonlight modes though, as it's not a feature I ever add to my lights.
Yes, you can. At least, on the very small few Iāve tried it on.
In general, itās not necessarily lower, but just different. Like, on one 7135-based driver, I found the following available modes:
fast PWM=5, phase PWM=3: zero output
fast PWM=6: 0.07 lm
phase PWM=4: 0.5 lm
fast PWM=7: 1.1 lm
So, I went with phase PWM=4 for moon mode. The 0.1lm mode was just a little too dim, and the 1.1lm mode was too bright.
This is something which needs calibration for each individual light though, or at least each driver+LED combination. The lowest and most ideal level for moon varies with the hardware.
My favourite Med mode gradually went down from 750mA until Iām at 350 nowā¦ Itās PWM 6/11/40/255 which (at 18kHz/fastPWM) gives me measured 1/36/342/2830 mA. A very nice mode spacing. This screams for
1x7135 pwm255 + 7x7135 pwm255
1x7135 pwm255
1x7135 pwm~low
1x7135 pwm~very-low
Imagine how looking at the new STAR firmware with ALT_PWM made me smile. I thought about how this might work (using mode_idx for voltage stepdown) but Iām sure youāll be quicker and your results are more reliable.
By the way, I still love the bi-directional mode change with short and medium press. Iāll never ever use anything else anymore. Itās fantastic to change direction without having to go through all modes, especially the high ones.
I should have guessedā¦
Moon has truly grown on me. Itās nice for a very dark environment and I use it all the time to look after the kids when theyāre asleep or woke up at night.
Especially the values where the lights start to light up. But Iām not sure whether this is a matter of fastPWM vs PhaseCorrect, I believe this is a matter of the resulting frequency, as the comparison with 150 Hz suggests.
EDIT: Skip my answer. Any 7135 driver would light up at these PWM values, regardless how many of them are on it. Arghhhh. Just the lumens are different.
EDIT 2:
I just flashed a stock nanjg 105c with most recent STAR Offtime.
- Moon canāt (and does not) light up as it defaults to PWM-3 at the moment.
Moon at PWM-4 with dual PWM (phase-correct-PWM (~9kHz) for Moon) does light up, but turns off when the driver gets hot (took less than a minute). So the issue of losing a low Moon is persistent. ALT_PWM with a single (or maybe two) 7135 is hopefully the way to go.
I finally got around to trying out STAR offtime. I like it. Feels pretty intuitive.
What kind of behavior could be achieved with offtime āno memoryā? I think Ideally the driver would always be next mode when the light is on, but from off it would always start on LOW.
