Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 6 of 6

Thread: Teensy 3.6 Underside Pins

  1. #1

    Teensy 3.6 Underside Pins

    I'd like to use the pins on the underside of the Teensy 3.6. These would be digital pins 40-57. The goal would be to have the Teensy be a duaghter board to a larger main board.

    It looks like I could use a surface mount header. But what would the spacing be?

    Looking at say Pin 46 would it be 0.3" from Pin 31? And then Pin 47 would be another 0.1" for a total of 0.4" from Pin 31?

    It seems like that would be the case, but I don't have calipers or anything to measure tenths of an inch.

    If anyone knows what length headers, that would be very helpful too...

    Thanks!

  2. #2
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,991
    With the exception of the 5 through hole pins for the 2nd USB, and the USB/power pads, all of the pads that bring pins out are at the standard 0.1" spacing. The 5 USB pins have 0.1" spacing between them, but the offset from the main row of pins is not 0.1".

    There are protoboards made to make it easier to access the bottom pins, such as:

  3. #3
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    8,799
    The OSH board in this post may help - more in the rest of that thread as well :: Accessing-bottom-pads-on-T3-6

  4. #4
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,991
    Quote Originally Posted by defragster View Post
    The OSH board in this post may help - more in the rest of that thread as well :: Accessing-bottom-pads-on-T3-6
    Thanks. I now remember that board. I thought I had saved it in my internal list of Teensy boards, but evidently I didn't. When I went looking for the 3.6 boards, I only found the Talldog boards.

    FWIW, I've used the FrankB boards for Teensy 3.1/3.2 to access the underneath pins. It is easier to solder these types of boards, than having to put in headers (and get the headers properly aligned).

  5. #5
    Thanks for the info.

    It shouldn't be too hard to get a header soldered on. Since they're standard 0.1" spacing I can just use a strip of perf board to align the surface mount header in the center with the already installed through hole headers on the edge. Then just tack it down, remove the perf board, and solder the remaining pins.

    It will be going into a custom PCB, so I don't need to breakout the underside pins to breadboard friendly layouts or to headers for wires or anything.

  6. #6
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,169
    Yes, best to solder the header to the SMT pads first. Try to align in the center of the pads if you can. Then solder the other through-hole ones with the already-soldered header and new headers lined up in the holes where it will mate. If you didn't get it perfectly aligned on the pads, usually doing things in this order will allow a little adjustment with the other pins, so the combination can still mate with the perf board.

    If you solder the through hole pins first, it means the alignment of the header on those SMT pads has to match very closely for everything to line up on the perf board holes. If you get it off too much, usually then you're stuck with having to drill some of the perf board holes larger.

    The SMT pads aren't strong enough for the header to repeatedly mate with a normal socket.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •