A small(heh, heh) first run of the boards has been ordered for testing and I should be able to try one out in a few weeks. Thanks a bunch to Mattaus for getting this done for me/us. I’ll post again then to see what level of interest there would be in a larger order. They should end up pretty cheap since they’ll come without any smd parts included. As far as I know this will be the only 10mm Attiny/7135 driver around and stackable for customizing max output as high as room/cell supply/and soldering skill will allow(I figure 1-1.5A is doable).
How nice that you are still into this project, there have not been blf-originated drivers that make it to production (none up to this day?), and i like this one!
Thanks Scott and Matt, greatly appreciated what y’all are doing here. I’ll be working on flattening out some chips so I can stack more and shoot for 4.5A on a 10mm board. 
Isn’t there a higher rated chip than a 7135? Hmmm……
You and Scaru should team up on something BIG.
Big/little?
I want to make the first 3000+ OTF lumen 3” keychain light. 
Any 14250 cells that can handle 4A current draw lol?
There’s that…
Be great to see how it looks in the palm of ones hand.
What pcb fab did you send it to? PCB Thickness?
Mattaus ended up using Oshpark so the pcb will be 1.6 mm. He and I both would have preferred 1 mm given the small size of likely hosts but Oshpark doesn’t offer that option. The good news is the stamp to mail it will cost more than one of these. The first few will be tested before an order of any real size is done.
SeeedStudio will do 1mm boards for dirt cheeep…
Yeah I normally use Seeed Studio, but decided to use OSHPark for three reasons:
1) I think they're quality looks better though I won't know for sure until I get some boards from them. The gold plated pads is a very nice touch.
2) For the purpose of this test run they are stupid cheap (85c for 3 of them, with free shipping) where as Seeed would have set me back $15 minimum plus more if I wanted Lead Free (which I always do).
3) OSHPark are U.S. based (no idea where the FAB is located though), so I figure Rufus would possibly get them faster that way as I had them shipped straight to him rather than half way around the world to me first.
I agree, 1.6mm will look stupid thick on such a small board. This is a small test run of only 6 PCBs. If they work out well then we'll investigate them further. Still, 24c a board is pretty hard to beat ;)
- Matt
I don’t know about you guys but I feel like a kid on Christmas.
Not so much as me Scott, I’ve got this ongoing project over here looking for this board. And if I’m not mistaken, it’s already got a 1.6mm board in place. I just need 1.5A or a smidge more.
Really looking forward to this working out well.
Thanks Matt, for the detailed explanation and the good work!
OSHPark’s fab is in the US.
Seeed will do ENIG gold…
If you are going to build any quantity of these, I go with Seeed. For protos/small quantities I use OSH.
Assuming they work out I’d like to go with the thinner pcb from seeed. I’d be surprised if we got to 100 boards committed but this is something I’ll be doing regardless.
I have 20 of the 10mm SinkPADs so I can see me possibly using at least 20 of these boards. If that helps any.
Given that these will allow custom ui’s in AA and AAA mods with lithium cells I hope that there will be at least some interest. It seems that there are plenty of 1.5-3V drivers for AA and AAA single cell hosts but not a single 7135 type for 4V and with one of the high voltage mods one could even put an mt-g2 in a AAA Minimag. Whoopee! Just no idea yet how many diyer’s will be interested in doing pcb transplant surgery. Being untrained and unskilled and still having done work on this small scale I know it’s possible and should create some new options but until others say “I’d like to do that too” there’s just no way to tell. Well soon see who wants some and I’ll order plenty of extras and save the files.
Looks like Seeed would be $96 for 100 (at least, you usually get extras) boards up to 50mmx50mm with gold finish. You can get 0.8mm for no extra cost. 0.6mm would be $16 more.
If you could find a way to cut out the 10mm boards from larger panels, the cost would be dirt cheap. You could get around 20 boards from a $1 50x50mm board.
Once the prototype tests out good you could get some awesome boards really cheap.
Want a secret for cheap tiny boards?
These things are 10mm. You can fit them 4 across on a 5cm x 5cm board. Don’t worry about cutting & screw 0.8mm or 0.6mm thick.
Kapton all the way! $65 5cm x 5cm Thickness? 0.15mm. Cutting? Scissors. 192 boards $0.34 each. Now they are 10mm so you could do 5x5 = 300 $0.22 each.
If you go kapton I won’t be able to resist… :~
You could mail them out under the stamp on a post card. :party:
Helios, does this quote mean that your suggestion isn’t acceptable?
“This service requires single unit, no sub-boards. Array unit or combine different design into panel is not permitted.”
Multiple small boards within the parameters of the 5x5 would be an array, would it not?
How would such a thin, flexible board mount? Hard to solder to the ground ring for a good positive ground? Would it hold a contact spring for the battery positive? I guess with it that thin, a simple contact board could be used.