DIN-Uino Proto4 (for Teensy 3.x)

Makes your Teensy project a neat, DIN-rail compatible device.

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As part of my DIN-Uino prototyping & packaging project, this is my second proto-board design for a specific CPU module family.

This time - it's for the Teensy 3.6 (and compatible footprints).

STATUS: Essentially done. Now a bit of documentation to write, and with some luck and a lot of coffee... you'll soon find the bare-board up on Tindie. Later on... maybe even partially assembled (power supply section at least).

DIN-Uino Proto4 board, some salient features:

* Industrial-compatible 24VDC (I'm aiming for a 12-25V safe operating range) power input with 5V/3.3V output. Connections via a 2-pin Phoenix 3.81mm header.

* Room at front edge of PCB for a maximum of 48 pluggable screw-terminals (Phoenix 3.81mm pitch).

* You can use single or double-stacked Phoenix-compatible headers, vertical or right-angle.

* Uncommitted right-angle pushbutton switch. You can wire it to RESET, or use it for some other function.

* 4-layer PCB design, with internal GND and POWER planes for power distribution.

* The POWER plane can be connected to 3.3V (default) or 5V (optional).

* Distributed power-vias allow easy access to the internal GND/PWR planes.

* On-board USB-A(host) or USB-B(device) connector, already wired to the Teensy's native 5-pin USB header. The USB connectors are positioned at the edge, easily accessible even if an enclosed DIN-mount enclosure is utilized.

* Of course, this DIN-Uino Proto4 board is compatible with the related DIN-Uino mounting hardware and enclosure system.


Schematic: DIN-uino Proto4 board.

Adobe Portable Document Format - 126.26 kB - 09/26/2017 at 01:53


  • Progress: DIN-Uino Proto4 board

    kbdhog08/31/2017 at 20:13 0 comments


    Proto4 board fully populated with all the Teensy-related headers:

    A little closer view:

    Thanks to free samples from Samtec... I've worked out the combination of mating headers necessary for the through-hole and SMT-mount headers to have the same mounted-height.

    On the Teensy 3.x board:

    1) All through-hole header strips: Standard size (~0.230" long pin above 0.100" thick insulator). The strip should be inserted on the bottom side then soldered on top.

    2) The SMT-mount headers should be Samtec P/N TSM-1xx-01-T-DV (or gold, -G-DV).

    On the Proto4 base board:

    3) All socket-header strips for the Teensy's "standard" header strips: standard socket-strips with an insulator height of ~0.330".

    4) All socket-header strip for the Teensy's "SMT-mount" header strips: Samtec P/N SLW-150-01-T-D.

    With this combination of headers, the mated PCB spacing (between the Teensy and Proto4 board) will be ~0.430".

    What a rip-off...

    Of course, when I was trying to figure out the right combination of headers/sockets I had initially selected the wrong length header-pin for the Teensy's SMT pads. Argh! I should have done a little math before soldering them on to the SMT pads on the Teensy.

    After Samtec sent me the correct parts - the challenge was then to carefully remove the SMT-headers and replace with the new ones. Not easy... I ended up ripping some pads off the Teensy board:

    This is not a new problem... I've read elsewhere that this isn't an unusual result. Either from de-soldering, or even just trying to unplug a "fully headerized" Teensy (you have to be realllly careful prying it loose). I'm sure there is a good technique for de-soldering these headers without damaging the pads - but in the 15 minutes I spent on this task, I didn't figure it out. I can still use this Teensy, just not the SMT I/O pins.

    Summary: Everything seems to fit nicely. Next step? A Teensy-blinky project? I really don't have a need for this DIN-uino Proto4 board right now (today), but very soon... I'm sure it will become quite handy.

    16-Sep-2017: The first board is mostly built, see gallery.

    The SMPS (5V) and LDO (3.3V) power rails are solid. The internal power/gnd planes are NOT shorted (thankfully!).

    Now I just need to sort out one little point of confusion: what are the appropriate SMT (bottom side) and TH (all others) header combinations to use on the Teensy, so you can plug it in and everything mates up properly. All the holes on the proto-board are in the right spots, that's not the problem. It's the combined "board stacking height" with different combinations of SMT and TH headers that is a tiny problem. Off by 0.1". I think I have the answer... but if anyone has good advice, please share.

    11-Sep-2017: Boards have arrived! So far they look very good. Parts have arrived too... so the next step is to slam together the SMPS section and confirm it's working properly.

    3-Sep-2017: Found a few more tweaks, I'm done. You know how it is - whenever I see blank PCB space - I want to put something there! If I don't send it off now - I'll be sure to find more changes to make. Final version front & back renders posted in gallery.

    *** Sent out for fab today! Should have some nice boards in a couple of weeks or less.

    31-Aug-2017: I think I'm finally finished tweaking the layout. Just about ready to send off for initial fab.

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Enjoy this project?



kbdhog wrote 09/20/2017 at 15:43 point

Yes! 25yrs ago they used to charge by the hole... they would have loved this!

This "interstitial-via" concept for PWR/GND access just popped into my head, though it's probably not new. Seems cool, but I'm not sure yet how practical it is in actual use. When I build my first Teensy-based project, I'll certainly find out how much I love (or hate) this scheme. If my results are favorable - I'll re-spin the other "Proto1" board to use the same scheme.

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esot.eric wrote 09/24/2017 at 05:14 point

Real nice... smt decoupling caps, pull resistors, solder blob power at every pin... transistor emitters... real nice.  I usually skip rows to save on holes. ... coulda swore I had a more specific writeup on that... and doable with two layer :)

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kbdhog wrote 09/25/2017 at 18:21 point

Thanks! Very nice... I like the ability to break out pins like that, especially with BGA's or other "difficult" packages. At least you can have a fighting chance to play with those chips a little, even if the connections aren't "optimal" impedance-controlled microstrip or diff-pairs.

I was sure this "interstitial via" scheme wasn't a new concept, and your link simply confirms that this might be a good idea. It's very difficult to come up with anything new these days. However, if it's a good idea - it doesn't really matter where it comes from.

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esot.eric wrote 09/25/2017 at 20:43 point

indeed... speaking from experience, it is really handy with DIPs and smt discretes... A bit difficult to work around for, e.g. 0.05in spaced smt DIPs, having empty rows helps. And can still (even with empty rows) have a power and ground via near every pad.

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davedarko wrote 09/16/2017 at 09:06 point

Boardhouses must love you :D

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Stuart Longland wrote 09/16/2017 at 11:57 point

I'm guessing with such a holy design they only make these on Sundays? ;-)
Still a pretty interesting board layout for prototyping.

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