Looking good! I’m hoping to get more time for this in the new year. I’ve got plenty of projects, which always seem remarkably similar to yours 
Thanks for your work!
Maybe this could be a replacement driver for my SWM C22? Would it be possible to control the 2 LEDs with one eswitch? I don’t like the UI but the light itself…
Subscribed.
PD...Please forgive my ignorance....
Is this 3 channels 1 emitter? or...
3 channels 3 emitters?
It’s definitely possible to control 2 with one switch, someone would just have to write the FW for it. Unfortunately that’s not really in my skillset.
Bugsy: 3 channels, 1 or 2 emitters
Yeah...well...you know someone that can 
It would be worth putting together a couple samples to send for R&D
I've been trying to understand it as well. I've been analyzing the layout, and PD's reply to my question above. The default layout of this board is like a FET+1 driver -- drives only 1 emitter, but instead of 2 paths the MCU controls for the LED output (a 7135 and a FET), there are 3 paths: one single 7135, a bank of 6 7135's, and 1 FET.
The limitation we have to work around with the ATMEL tiny MCU's is that we can do PWM's on only 2 output pins, but with PD68's design, the FET is simply switched ON or OFF with no PWM's because you don't need them. You can use the bank of 7135's for all the in-between modes, and use the single 7135 for the lowest modes.
My preference for a mode set is 5 modes w/moon, so in the Narsil firmware, you choose a 4 mode set plus you turn on moon, so modes are as follows:
Mode 1 (moon): 3 or 5 PWM value on the 7135
Mode 2 (~2%): 30 PWM value on the 7135
Mode 3 (~10%): full output on the 7135
Mode 4 (~40%): 80 PWM on the FET
Mode 5 (100%): full output on the FET
So you can see from above, the first 3 modes are actually on one 7135, and the top two modes are only on the FET. TK's spreads it out, sharing the 7135 ad FET through the mid range modes.
So on this triple down driver, if I wanted to implement my 5 modes on it, I'd use the bank of 7135's only for mode 4. Six 7135's is 2.1A, so that would be 42% for a 5A max FET. However, as you know max amps on a FET varies based on the LED, cell, cell's charge level, etc., so these percentages will vary. The 7135's will give you something more solid, but still at some point, 2.1A will not be achievable depending on Vf of the LED and power/charge of the cell.
The advantages of this implementation is we are getting very efficient on all modes because PWM's on a fully open FET is pretty inefficient - it's more wear/tear on the LED by cycling 5A at a high rate, you get the tint bias for the 5A, and lumens/amp ratio is down. I can even see using only 5 7135's instead of 6 to get closer to a 35% level for your next level below hi/max. Another thing is you can treat using a full output on the 7135 bank as your hi mode, and implementing the full FET as a turbo. We have a lot of flexibility here with the 3 channels of output and can achieve very close results to a true non-PWM driver, like the LD-1/LD-2.
I have no problem with sending a R&D sample, but I would want her to express interest in it first. I know she’s a very busy woman, and I don’t know if this is anything she would like anyways.
Technically it will work just fine using the 7135’s for separate outputs with existing firmware, you would just need to modify it a bit to get the FET to work.
Another application of this driver is using it exactly the same as a FET+1, but having another PWM LED output available for something like a RED LED, or battery/status indicator light. Since you can go up to 2.1A or 2.28A (380 7135's) without stacking, you can use the full bank to do all your modes accept the highest, or turbo, which is the full FET.
Since TK wrote the Ferrero Rocher firmware, she certainly knows exactly how to handle 3 output pins with 2 being PWM's. It's well within her comfort zone I'd think, but interest/time of course is an issue.
Correction ....2 coders ;)
Not trying to commit anybody to anything but the skills you all possess just amaze me.
Pyro1son had been working on using Pin3 output at the same time I was working on my Olive S6 and almost had it working, I think he just got busy with life. I don’t think we will even need a new firmware, just modify one like blf-a6. We already have shortcut codes for turbo and strobe, etc. We just need a shortcut code for Pin3 and we’re done.
Just finished cleaning up some very minor things on the board. Link is updated.
Since Tom stared at the circuit for awhile and didn’t spot any errors, I’m going to go ahead and order some.
Edit: 20mm and 19mm added to post 1.
I still wish there were a good driver and firmware for a true two channel and two output driver. I have a number of projects that would benefit from this. Right now I have a bike light that needs a driver to power two nichia 219s on one channel and one xpl on the other. Ild like to drive them all at around 3.3amps on hi from four 18650s. But I just don’t see this kind of driver out there…
- Didn't think my stare was worth much. I can follow it - just noticed your comment, so spent a couple more mins on it - looks good to me..
- the C1/D1 order is fine
- R1/R2 voltage divider circuit looks ok
- the OTC pad connected to pin #2 is fine - doubles as an e-switch pad
- the Bleed Resistor I understand you need for the lighted tailcaps - all good
- just wish you could have fit the extra cap after the diode and close to pin #8 (Vc pin). I'm rigging up a 0.1 uF cap across the Tiny85 MCU between pins 4 and 8 for now. It's the only solution I know of - the problem it fixes is happening more regularly now on the wight FET+1 drivers, so I'm doing it on all of them now. When I saw it working fine on one light til I tried a LG MJ1 cell, got me think'n it's very borderline. The MJ1's are not even a top high amp cell. I think Richard will either confirm or find a better solution - he's the only one I know of now that has the methods/tools/interest to do so, but there probably are others.
It's really not difficult to do, just takes time/effort/interest, and enough board space, which you may have in a bike light. Or you could do it manually now for sure with a couple of 7135 'farm' boards. You would wire up the two PWM output pins from the MCU, pins 5 and 6, to the slave 7135 boards, where you could have 9-10 7135's on each (9 would be 3.15A, 10 would be 3.5A). There's probably been similar projects done on BLF with a Tiny13A based board, either OSHPark custom or a Nanjg.
Sorry Tom, i haven’t been following the 25/45/85 thread. I wasn’t aware of the problem. I have a layout in my head I can swap the BR for a cap, maybe I can get to it later tonight.
Hummm? So do you think there is a open sourced firmware out there somewhere that is close enough that I could “tweak” it to fit my needs? I am far from building my own drivers, but I am determined to find my way there:) Right now I understand the idea of slave board, but that is about it. I’ve swapped some resistors and fried a couple drivers… That’s my qualifications at the moment:) Im going to attempt adding 7135’s this week. So, atleast I’m moving forward.
I will quiet down and let you get back on track now as i don’t want to hijacked this thread.
Nice job, Pilotdog! You’re really pushing things forward.
I haven’t even tested out the DoubleDown, but will do for sure, because I love that bypass-hole-design. I’m sure you would’ve done it to the TripleDown-17mm if you found enough space… But in terms of space you managed to fit a lot into 17mm.
I’ve used a A17DD-SO8 in a Convoy L2 lately, drilled a hole through the triangular LED+ pad and managed to fit in 18AWG silicone wires. I really like the way the LED+ is arranged there. With some recent drivers I don’t feel comfortable using 18AWG if I have to use the pad and it’s very close to the ground ring. The width and shape of the ledge this ground ring sits on varies with different hosts and I find myself worrying about clearance sometimes.
Well thanks for the compliments Chouster. Yeah, there was no way to get a pass through on the 17mm, and personally I hate the center pad on the S08. I find it a huge pain to solder to. This board has a bit more room around the outside than some of my others, and the 20mm board has a full 3mm of clearance around the edge.
I haven’t soldered on the S08 pad yet, probably never will, I just like the fact that you can drill and run a 18AWg wire through. Maybe there would be space for a hole if you would skip the LED+pad, but I know you’re not a fan of that. Anyways, very nice job.
Uploaded 17mm Rev1.1z. Zener-ready (will also work for TomE’s extra cap.)