USB protrusion on PCBs, SWD pinouts (rant)

[Renate]

The Seeed Studios Xiao SAMD21 are tiny boards and the USB Type C female sits right on the edge.
You can make a project box with 2 mm walls and the connector will be a bit recessed.

The standard "Blue Pill" extends almost as far.
The standard "Black Pill" extends even less.
Why don't they have it protrude more?
Looking at newer STM boards some of them are just flush.

Then there's STM's 4 pin SWD interface on the back edge.
Why in the name of pineapple on pizza do they have to waste PCB real estate drawing the pins of the connector?
Why couldn't they include a 5th pin for reset? I know, some people don't want/need it, but would it kill them?

So, my question is: What hot, small 32 bit ARM boards 1) have protrusion, 2) a sane SWD, 3) maybe even a mounting hole somewhere?
Or barring that, boards with no USB connector, but USB 2 brought out.
(I know that "Blue Pills" have the USB on GPIO, but their hardwired D+ pullup is a killer. And it's ancient.)

On Aliexpress I can find waterproof USB Type C sockets that have a nice 2.1 mm shoulder.

[thm_w]

Cheaper to have the port not protrude, as it uses more PCB space. Not much though.

If you want those features, might make sense to make your own board. You aren't going to like the price of the commercial options.
https://www.adafruit.com/product/4382

Or use https://www.aliexpress.com/item/1005009392042521.html

[lichurbagan]

So, my question is: What hot, small 32 bit ARM boards 1) have protrusion, 2) a sane SWD, 3) maybe even a mounting hole somewhere?
Or barring that, boards with no USB connector, but USB 2 brought out.
(I know that "Blue Pills" have the USB on GPIO, but their hardwired D+ pullup is a killer. And it's ancient.)

On Aliexpress I can find waterproof USB Type C sockets that have a nice 2.1 mm shoulder.

Did you check Adafruit Feather M4 Express and Raspberry Pi Pico?

[Renate]

Thanks, Both are somewhat reasonable recommendations...
But they have some sort of evil 5 pin USB connector on them that I seem to remember from my Vacuum Tube 101 class.
Ok, I could desolder them and install a case mounted USB Type C.

To add insult to injury they persist with the stupid A1 terminology from Arduino.
I'm all grown up now, I prefer native GPIO designations.

Aliexpress doesn't seem to have any SAMD51, or at least any search only comes up with Samsung A51 replacement boards.
Just don't get me going on Aliexpress. Their goal is to distract you with bundles and offers on unrelated things.

[John Celo]

Grown up version is just ordering PCBs with exact layout you want.
Stm32 (and clones) require close to nothing to be functional, like 4.7uf + N x 1uf decoupling, 3.3V LDO with 2caps and they are good to go pretty much.
Interal RC oscillator is good enough for even FS USB.
This is very easy to do even for a toddler like me.
You can also avoid dealing with tiny parts, as there are many options in the very-easy to solder LQFP-32(7x7) package, etc.

Since you're very particular about mounting holes, millimeters, placements and protrusions sticking or not sticking out, there's just no need to torture yourself with "suboptimal" off the shelf stuff.

[voltsandjolts]

USB-C panel mount exists.

[Renate]

USB-C panel mount exists.

Mmm, I don't think that I can fit any adapters in this enclosure.

[Buriedcode]

The MCU "carrier" boards aren't really meant for actual products or serious work - sure they can be used that way, but that isn't what the designers intended.  Mounting holes? on a board designed to plug into a larger board on a prototype?  I'll agree some designed choices are questionable, and annoying, but I don't care because they're only a couple of dollars.

These days quality PCB's are dirt cheap..  and gives you freedom to do anything you like.  Often you can get them populated too if you need a decent run.  I has never been cheaper to make your own quality boards, you might be able to make them cheaper than anything from Adafruit, but Seeed Studios is excellent value for the quality of their stuff.   

[SiliconWizard]

Yes, just consider those boards as what they are: dev boards.

When you deal with more complex SoCs, it can be somewhat defended to use a "SBC" in a product, but even then, you are limited to the form factor and pins/connectors, which is why vendors offer "compute modules" to integrate. But a MCU and its few external required parts definitely does not warrant using a ready-made module, unless of course you had absolutely no intention to make a PCB to begin with, and that's rarely the case when making a product. For hobby projects, you do with what you find or can still design a custom PCB given current prices.

[Renate]

Yes, I do my own PCBs when there is a reason, like the dozen I built for a Modbus system.

But there is also sometimes a need for jelly bean boards for a quick knock-off project.
So far nobody has said, "I keep a handful of XYZ for quick projects" or "I standardized on my own ABC processor PCB".

[az1]

Yes, I do my own PCBs when there is a reason, like the dozen I built for a Modbus system.

But there is also sometimes a need for jelly bean boards for a quick knock-off project.
So far nobody has said, "I keep a handful of XYZ for quick projects" or "I standardized on my own ABC processor PCB".

Between Feather and Seeed Studio you have a *ton* of flexibility.  Boards in both form factors are available with ESP32, STM32, nRF, RA, and NXP chips.  If the naming conventions are too bothersome then roll your own PCBs.

[thm_w]

Mmm, I don't think that I can fit any adapters in this enclosure.

If you are 3D printing enclosures, I'm sure you can make it work.
Have the outer wall 0.6 to 1mm thick in the area around the USB port.
Or fully retain a USBC male to female extension cable inside the enclosure.