BLF17DD Info Thread - Reference

Out of curiosity I'd like to know how everyone would feel about a production run of this board? I just ordered a pair from Mtn electronics to try out so my own interest will be based on testing of those.

However assuming that works I was thinking perhaps we could look into having some fully assembled boards made in china.

Has anyone here ever done this that would like to chime in?

I've had some quotes from a place or two on the fully assembled drivers, but in low quantity (100 pc)the price was still like $12 each I think.


The board(s) this thread was suppose to cover I'd consider sort of obsolete now. wight's boards are the "latest", but there's lots of spin-offs. C_K has gone 100% into the PIC based designs (think he is not continuing with the 13A designs), while wight is staying with the Atmel 13A designs, so far. The latest R&D efforts are on a port to the ATTiny25, which doubles program space for one thing, and I think also includes temp monitoring. The PIC and 25 based board are the immenent future, but wight has a ton of form factors/options available all based on the latest upgrades (zener, OTC, dual FET/7135, etc....), and with a good known source for a FET. The Vishar based FET designs have an issue (I guess) for getting a source for a wuality FET right now.

The 13A just can't do everything we want it to do - the 1K space is a roadblock now.

Sorry, but this PC board stuff is so hot and changing almost day by day, it's a tough call to say when a good snap-shot can be taken. Richard has been doing his own spin-off designs, I believe, plus lots of R&D, working with JohnnyC for the firmware, etc. wight is the guy to follow now, I believe. He either doesn't have a regular job, or doesn't sleep -- I have no clue how he's had time to do so much for this forum! I find his board designs cutting edge: exc. layout, exc. efficient paths, etc., plus his research efforts to finding hot performing FET's, and other parts has been a huge contribution. Plus he's very actively supporting, tweeking, etc.

Heh, . There’s definitely a lot of tweaking going on. If only there was more “completing of projects” or “producing of buck drivers” going on. :wink:

Remember that the ATtiny25 is physically the same as the ATtiny13A. Porting to the ATtiny25 should pay off for all drivers which currently use the ATtiny13A! That’s why the 25 was selected instead of the 45 or 85, which are both slightly larger and don’t fit properly on these tight PCBs.

And pray tell what does “Porting” mean? Last time I ported anything I bored holes in the end of a .45 Long Colt barrel so the handloads I was feeding it didn’t make the front sight attack me.

In this case, “adapting” would give the correct meaning.

So this would mean writing firmware to utilize the 25 in place of the 13A?

Hel*, I can’t remember what everything is now, why would I want it even more complicated? lol Sad but true…

essentially yes, but “porting” usually implies taking the existing program and just tweaking little parts of it to make it work on different hardware. the overall program will be mostly the same, just little “nuts and bolts” will change. However, with the extra space available on the 25, I would expect the programs to get much more feature-rich (and therefore complicated) once it is ported.

Can the 25 handle my favorite UI: moon, low, high, no memory?

I think a lot of the space issues crop up with features such as:

  • Momentary button support. (e-switch)
  • Thermal throttling.
  • Any use of curves with tables? (fancy ramping)
  • Complex UI.

I’m probably forgetting some things, and since I have not been attacking these things myself I don’t know how big a problem features like status LEDs have presented in terms of space.

A production run would be cool, but first we’d need to settle on a “final” design for it. Wight has been improving things almost daily, so it’s not really stable yet.

However, I get the impression that the most popular driver would probably be a 17mm single-sided model with both a FET and a single 7135 chip, OTC, and attiny13a or attiny25. If there’s room, also a pad for a zener. This would cover almost everyone’s needs in the most common size of light — blinding highs, low and efficient lows, off-time or e-switch UI, several popular firmwares, and easy to reflash. Not much room for solder stars though, so people would need to mostly agree on a default firmware.

He also made a pretty amazing 15mm model with everything above except a zener, which I’m hoping to try soon in some 1x14500 lights.

Hey you asked :smiley:

Original ATtiny13A > ported over > ATtiny25A

Porting also means heavy set guy….er…no that’s portly, sorry I was thinking of myself :stuck_out_tongue:

:slight_smile:

Hey look at that! I was spot-on without looking it up 8)

and then some

If the ATtiny13 can do all that…imagine what the coders could do with 2X the space…think “dual group modes” and whatnot

yup yup

I make a good living off of porting code - that's what I seem to do most of the time, lately, for the last few years... We went from custom embedded hardware (1st generation) in ASM/C/C++, to COTS (Commercial Off The Shelf) boards w/custom plug-in hardware (2nd generation) Win CE based in C++, and now (3rd generation) to Windows based Panel and table PC's in C#/.NET Smile. Maybe 150k-200k LOC's (Lines of Code) ported along the way...

Ho, ho, ho, off to port code we go...

I’m glad I haven’t had to port code very much. Occasionally fix bit depth or endian issues, yes. But mostly I get to use Python and shell, which makes all that moot. Before attiny firmware, I think the last time I had used C was in the 90s. But I like C, it’s still one of my favorite languages. I’d probably like Go too, but I haven’t really used it yet.

Most of the code I write is basically prototyping anyway. Proofs of concept to decide on a good design or test potential solutions, and then if it turns into important infrastructure someone else can maintain it. Or little bits of code to break things. Or anything which satisfies the rule of three — the third time I have to do something nontrivial, I automate it.

I built a BLF17DD from Mountain Electronics. It didn’t work. Positive and negative in were shorted together. I saw a line across the positive LED pad and scratched it out with my camel bone handled pocket knife, which fixed it.

Looks like a bit of extra solder may have squeezed thru that via and accidentally bridged on the ground ring

I’ve used that same board from OSHPark a couple of hundred times, never saw anything like that happen.



Ya cuz a knife with a plastic handle never would have worked.




LOL> Sorry, I just couldn't resist. Glad you got it fixed man.