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Topic: perma proto boards -- any that really match breadboard pattern? (Read 2143 times) previous topic - next topic

ChrisTenone

I dunno.  Some of those boards also have a barrel jack, both 5V and 3V regulators, and switches to select 3V/5V on each side.  Pretty nice for < $1...

Very nice. What's that yellow six pin connector on each side of the regulators.
What, I need to say something else too?

Paul__B

Very nice. What's that yellow six pin connector on each side of the regulators.
That is an extra spill for 5 V and ground, and 3.3 V and ground pairs.

My point was simply that like the Arduino boards, the regulator(s) are incapable of providing much current when fed from the "barrel jack".

westfw

Yeah.  Skimpy heat-sinking (well, none.)  Still, probably not worse than the Arduino itself, either...

ChrisTenone

Yeah.  Skimpy heat-sinking (well, none.)  Still, probably not worse than the Arduino itself, either...

They look like they'd be useful for class projects.
What, I need to say something else too?

Tazling

I rushed off an order for the red Sparkfun "perma breadboard" proto board, and also a black one from OSEPP.  They arrived today.  Turns out the black board is a shameless copy of the Sparkfun board :-) so there is only one product to check out, not two.  And according to my BB power supplies, the scale is ever so slightly oversize, so that I will have to bend p/s pins to get them to fit.  The two power rails are just a tick further apart than the p/s assumes.  A tiny error, but enough that it doesn't just slot in like it does on a real breadboard.

Also, to my dismay, the sparkfun-type proto board is actually larger overall than the same configuration of breadboard, which means (gasp) it will not fit into my project box in the same footprint as the breadboard now occupies.  There is no extra room, so argh! I'm going to have to go to the bandsaw and slice the edges off the proto board.

So I'm mildly disappointed.  Was hoping these other "solderable breadboards"  would just work w/o modification or struggle.

I do think these cheapie p/s are handy though.  I happened to need both 5v and 3.3 and higher amperage than the Arduino can put out, so the compact dual-voltage P/S was the perfect tool for the job.  With the addition of a row of 470uF caps across 5vdc and gnd, it can actually handle a brief jolt of startup current (higher than its rating) to the touch screen. The Due, powered via its USB port, can manage the rest of the loads.

ChrisTenone

What, I need to say something else too?

westfw

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and higher amperage than the Arduino can put out
It's not clear that the power supply boards can provided much more current than the Arduino itself.
(Perhaps bursts, as you said.)  It's more of a power-dissipation thing than the specific chips involved.

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according to my BB power supplies, the scale is ever so slightly oversize
Really?  My protoboards measure pretty much exactly 0.3 inches from the signal holes to the power holes, and a terminal strip with two pins removed fits fine...
OTOH, it looks like the SF board has the power holes offset 0.05in in the OTHER direction, which could be a problem.  (although, that shouldn't matter, with the power supplies I looked at...)
Do you know exactly which power supply you are using?

Tazling

Sorry, I meant that my total load is more than the Due can support so the extra P/S comes in handy.  The P/S indeed does not by itself provide more max current than the Due.  But it provides just the additional capacity I need for a total that is more than the Due can provide.


I have a small collection of these bb p/s (more on order, but from Banggood so taking forever).  They all look identical but some have YwRobot stencilled on them.  Boards are black.

Paul__B

Really?  My protoboards measure pretty much exactly 0.3 inches from the signal holes to the power holes, and a terminal strip with two pins removed fits fine...
But is the spacing between the "column" rows and the power rails actually a tenth inch multiple on the solderless breadboard?  You do not usually bridge components with rigid spacing between the two, so they may well not be.

And the "Breadboard power supply" module may be designed to match a known intolerance.

Hint: Does it fit turned sideways, into the "column" part of the board?

Tazling

If I take my YwRobot BBPS and rotate it 90 degrees so that its long axis aligns with the long axis of the PCB, I can get the 4 pins on one side of it to slide easily into 4 holes in the component area on the SparkFun red solderable BB.  They fit nicely whether inside one column of holes, or spanning the gap in the middle.  I can also get those 4 pins into the component area and the power rail at the same time, but the PS ends up skewed slightly as the pairs of holes in the power rail don't line up with the lines of holes in the component area.

OK, now I rotate it back to its normal orientation, long axis of PS aligned with short axis of PCB, connector outward.  Now we have 2 sets of 4 pins that want to drop into the power rails on each side.  Note:  the 4 pins still drop perfectly into the component area.

What about the rails?  Any one set of 4 pins on the PS aligns perfectly with one rail, on either side (i.e., when either outer edge of the PS just overlaps with either outer edge of the board and most of the PS is off the PCB).  So the side-to-side spacing of the power rail holes matches the PS and so does the longitudinal spacing.

HOWEVER.  When I orient the PS normally, in the way it's supposed to be mounted, and try to engage with both rails at once, I find that the rails are just a tick too far apart.  On either one rail or the other, the pins end up contacting the metal rim around the holes instead of the hole itself.  They contact the metal rim on the side towards the centre of the PCB, so the holes are too far apart by about 1/32".

Now I think that with needle nosed pliers and careful perseverance, I can bend those pins so they will seat properly or at least workably.  But why do I have to?  Surely these bog-standard Chinese BBs which always match these bog-standard Chinese P/S so perfectly are well documented, and it would have been easy to make the PCB match the popular product?  Maybe I should be shopping for a bog-standard Chinese solderable BB :-)

The idea of having a few fabbed is growing on me...  but I have never edited a PCB design file so it would be a bit of an experiment :-)

Tazling

You could easily have 10 boards that match your requirement exactly (as long as they don't exceed 100mm length - about 38 positions) made for about $3/board...  You can even download the Adafruit design files and modify them as needed...
Also, I have an EAGLE ULP where you "run protoboard", specify the number of rows and where you want power rails (inside, outside, both), and it'll plop down the design on a PCB...  It currently uses the 0.3 inch separation for outside power rails...
OK westfw, I'm willing to reveal my abysmal ignorance to the whole darned world.  Eagle is a CAD program for making PCBs?  So I googled that and found that there is a free version for hobbyists and they do compile for OSX, so I downloaded it.  The size limitation seems hugely generous for my purposes.

What is a ULP?  and how might I get one from you?

I gather that the workflow is something like:  Run Eagle, create design, export in some industry standard file format, send file to board fab lab, send money, wait for goodies to arrive in mail?

Are all fab labs the same or are there some you would recommend above others?  Where for example, would I find the $3/board price for qty 10?

[Aside:  If 3d printers were capable of printing PCBs that would be the excuse I've been wanting, to waste some money on one!]


westfw

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What is a ULP?  and how might I get one from you?
A ULP is a "User Language Program", a capability where EAGLE lets you write C-like programs that do things beyond its normal capabilities.  It's wonderful.  A protoboard consists of hundreds of pads, connected in a specific pattern, which is a pain to do manually.  The ULP lets you say
"run protoboard", specify the details parametricaly, and off it goes...  I'll attach it here.

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the workflow is something like:  Run Eagle, create design, export in some industry standard file format, send file to board fab lab, send money, wait for goodies to arrive in mail?
Yep.  In your case, I'd add "print test copy of PCB and see if the holes line up.  Move groups of pads around until they do."

If the Adafruit or Sparkfun boards are really close to what you want, you may want to note that those are also EAGLE designs that you can download files for, and it might be better to adjust them (they have prettier markings than what the ULP currently generates, for example.)
Some PCB houses will accept an EAGLE .brd file directly.  I've never done that, so I'm not sure which (other than oshpark.com, which would be expensive for this sort of board.)
The $3/board price comes from the usual $2 to $10 for 10 boards up to 100x100mm, plus about $20 for DHL shipping.  LOTS of places have approximately the same deal.
I've used, IIRC, Iteadstudio, Seeedstudio, JLCPCB, PCBWay, and OSHPark.
JLCPCB has been slightly faster (impressively quick, but I might have just been lucky) and they're my go-to site at the moment.  They have instructions for generating the files they need from EAGLE.  The way these companies work, AFAIK, is that they collect designs from "everyone" until they have enough to fill up a "panel", then they run it through their process, break the boards apart, and ship them to the correct places.  So the exact timing may be a bit variable.



I've never had quality problems, but I have pretty conservative designs...

Tazling

@westfw very helpful indeed, thank you so much for introducing me to yet another new world.

this sounds like a good skill to learn.  I agree that starting with a known design and tweaking it sounds smarter than trying to do a whole proto board myself.

you suggest printing the board for quality assurance -- does this mean that Eagle output prints at such an accurate scale that I'll be able to tell from the paper version whether it works?  that would be nifty.

I will fire up Eagle and make a n00by foray into it soon.  Your tips and hints are exactly what I need to get started.  Many thanks.

westfw

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does this mean that Eagle output prints at such an accurate scale that I'll be able to tell from the paper version whether it works?
Yes.  You can do things like toner transfer or expose photosensitive PCB material (techniques for homemade PCB making, dating to back when getting boards professionally made was very expensive) direct from EAGLE printouts.  It even has scaling adjustments to correct for any inaccuracies introduced by your printer.
There are a lot of on-line tutorials for using EAGLE, although I imagine that many of them are a bit out-of-date.  For instance: https://www.instructables.com/id/Turn-your-EAGLE-schematic-into-a-PCB/

MarkT

A ULP is a "User Language Program", a capability where EAGLE lets you write C-like programs that do things beyond its normal capabilities.  It's wonderful.  A protoboard consists of hundreds of pads, connected in a specific pattern, which is a pain to do manually.  The ULP lets you say
"run protoboard", specify the details parametricaly, and off it goes...

ObjectiveC, not C, I believe.  Very useful, I use an ULP to generate a script to
laser-cut a solder-stencil for each side of a board, and another to generate a BoM.
The ULP is designed for easy tree-walking of the PCB doc tree.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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