[released] 17mm 8x7135 with Zener & dual-PWM + stubborn: A17PZL

Hah, I’m game. Puzzle sounds like a clear winner right now.

I updated the resist on the bottom to make reflow easier. There are now well-defined dams of resist between every 7135 tab and the exposed ring. The actual exposed ring is now very very thin, but the copper layer hasn’t changed (it’s 1mm) and I’ve added exposed scallops to make up for it.

Of course the silk is updated to reflect the name

It’s getting better all the tiiime. The scallops for the expander boards? It looks like there are some acute angles on the 7135 traces. What are the two lines across the L+ pad? They look like breaks in the copper leaving only two narrow paths for current.

EDIT: Thanks!

  • The scallops on the bottom are there to increase the solderable area which is available on the ring without scraping. Just something to make it easier to solder the driver into a pill in other words.
  • The only acute angles I see are where PWM traces “Y” together on the bottom. Is that what you are referring to? I did those on purpose because I like the way it looks. I do not expect it to affect operation or fab-ability. Are you looking there or somewhere else?
  • The lines across L+ are just an artifact of the OSH Park rendering technique and Eagle’s Polygon output. Polygons in Eagle are turned into a series of overlapping lines. This is normal and only affects the previews.

Aha! Yes the traces from the pwm pads to the ring and also led- to it’s ring but you know what you want. I’ve tried to minimize these by making the connector traces radial to the rings and connect to a pad corner but if it works wgaf?

Right. I think it’s about 6 of one and half a dozen of the other. Eagle doesn’t have dedicated tools for either task as far as I know. Neither way looks entirely natural. Aesthetics probably would have settled the question - if one looked better I’d have gone with that. Instead I settled on the one that was significantly easier for me to eyeball.

In a circuit like this, at these frequencies, as far as I know the only potential problem would be with a super, super bad fab not being able to produce something. Eg an “acid trap” problem, although I don’t have enough experience to know if that’s a real thing or just something people on the internet chat/whine about. I don’t think we’re going to run into any of that.

Looking good!

Thanks RMM!

It’s really a pity that Eagle does not have more features related to aesthetics, snapping, geometric layout, etc. CorelDraw would make short work of those revisions and make the result look better. Fortunately the final product is a tiny PCB, so my minor misalignments shouldn’t be super obvious.

In Post 10, the last pic you show, you left out the little circle that identifies pin one on the MCU.

I don’t like it.

I LOVE IT! :slight_smile:

Hahaha, and of course the text is rotated 180 degrees from the direction the MCU should face. Wow. (that was unintentional)

Updated to v012 -

  • Added a covered 1mm via for SW+ hookup from rear. Either pass your <1mm wire through and just solder onto OTC pad if you want or scrape before assembly and solder directly into the via.
  • Improved LED- trace on bottom in order to facilitate the chunk eaten up by the 1mm via that was added.
  • Increased LED+ and LED- vias to 1.3mm for cleaner and easier 20AWG/18AWG installation. Not really very important here, but I figured I’d do it for consistency. Maybe you’ve got a long run to the LED and want to use big hookup wires.
  • Updated silk slightly. Added orientation mark for MCU.
  • Updated GND pours for cleaner and more accurate look on renders. :slight_smile:

I think it’s ready for a release. I haven’t built one yet. I never ordered any because I wasn’t happy with the driver yet in earlier versions.


https://oshpark.com/shared_projects/BiFm1nwn

Updated to v013 -

  • Swapped PWM outputs (Pin 5 & Pin 6)

I realized today that I had the PWM outputs connected in reverse as compared to RMM’s Moonlight Special. Of course that will work, but it was not a drop in replacement when done that way. IIRC the way it’s currently implemented in STAR requires code changes, not just define changes, so that’s a pain. I think I might have originally done it as a matter of convenience, or maybe it was just a side effect of this layout being derived from this one. Either way having the pins connected in the same fashion as the Moonlight Special is better for everyone in this case. I’ve updated the driver to be that way. As a result, the section under the MCU is a little bit less clean looking… but who’s counting? :wink:


https://oshpark.com/shared_projects/dC3iqMxp

Now I’m gonna have to get the firmware so I can flash em and check em out. :slight_smile:

Beefy traces? 3-4 high on the spring side? :bigsmile: JK, I find myself needing some more sane drivers than the FET’s on occasion and these will certainly fill the bill better than a qlite. :wink:

Are both 7135’s on the MCU side of the board controlled separately or just one? If one, which one? The on top of the Zener label? This IS primarily a low moon mode 3.04A qlite replacement, isn’t it? Or have I, once again, missed something?

I’ll have to re-flow the spring side for looks, hand solder the MCU side…with those big pads the MCU side will be a piece of cake. I elected to fully hand solder an A17DD S-08 the other day and it was pretty easy, even with the wrong tip on my iron. (I use the big bevel tip that comes stock with the Hakko 888, haven’t found a need to change it. I do resistor mods, stack chips, everything with this big bevel tip. lol)

Nice work Wight, some good looking boards you’re designing these days. :wink:

This looks super awesome… Thank you so much for sharing your work with us. What components do I need to start building these?

Only one 7135 is controlled individually. 7x and 1x. The one which is by itself is actually the 7135 next to the “B” in “BLF” - everything else is part of the 7. Unfortunately making one of the topside 7135s into the single would have involved sacrifices for the rest of the layout. It’s less obvious here because I removed the 7135’s Pin2 from the footprint, but remember that there is a pin connected to GND which goes all the way from the tab to the “front” of each 7135. I don’t worry about putting covered traces under this, but I do not place vias under it.

I also use the stock bevel tip for my iron (a Hakko FX888). I got finer tips, but never got around to installing them.

Thanks!

Don’t forget that with a small code tweak you can stack an FET on top of this thing (although with only on/off control, no PWM).

EDIT: Actually the single is next to the “F” in BLF. Sorry!

Thanks & you’re welcome!

In order to build these and get the 7+1 functionality (dual PWM / low moonlight) you’ll need the ability to flash an ATtiny13A, that is your biggest expense if you do not already have it. In order to flash drivers you’ll need 2-3 things, a USBASP and a way to attach it to the MCU (ATtiny13A). I’m using a Pomona SOIC-CLIP from Mouser, some colorful wires from eBay, and a USBASP from eBay.

For the actual driver hardware you may transplant an entire Nanjg 105c, Nanjg 105D, or Qlite. For offtime you’ll need to add a single 1uF capacitor, X5R or X7R is recommended but you can probably get away with putting almost anything in place of that cap.

With the stock 19.1k and 4.7k resistors from a Nanjg/etc stepdown and shutdown values for low-voltage warning and protection must be adjusted (for a 3v stepdown and a 2.8v shutdown maybe use 138 and 129?).

Here are some links:

My advice is to consider bumping your cart to QTY=100 on all the <$0.10 components in order to maximize your savings and have some on hand. They get very cheap in QTY=100.

Yes. [Insert NASA joke here.]

Sweet! Just ordered 6. I’ve got enough loose 105C/Qlite components on hand to build 8 or 9. Also have what I need to flash attiny’s as well. So the newest STAR firmware should work?

Correct, the firmware on JonnyC’s GitHub should work. JonnyC merged the dual_pwm branch back into the main branch some time ago, so stick with the main branch.

The constants to focus on when setting up the firmware should be these two:
#define MODE_MOON 3
#define DUAL_PWM_START 8