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

Thread: 4.1 pins descriptions

  1. #1

    4.1 pins descriptions

    There are 5 pins/headers on the 4.1 that go horizontal from side to side immediately adjacent to the SD card. What are they?

    I've found documentation for the SDIO pins, both of the back memory chips, ethernet, and USB:
    https://github.com/KurtE/TeensyDocum...y4%20Pins.xlsx
    https://forum.pjrc.com/teensy41_2.jpg

    But I can't find out what these five pins are.

  2. #2
    Senior Member
    Join Date
    Jul 2014
    Posts
    2,637
    until otherwise told by Paul, I would assume the pins to read (bottom view from left to right)
    Reset, Program, GND, 3.3V, VBat
    i.e. the same as for T3.5/6

  3. #3
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    3,672

    Cool

    Quote Originally Posted by kingforger View Post
    There are 5 pins/headers on the 4.1 that go horizontal from side to side immediately adjacent to the SD card. What are they?

    I've found documentation for the SDIO pins, both of the back memory chips, ethernet, and USB:
    https://github.com/KurtE/TeensyDocum...y4%20Pins.xlsx
    https://forum.pjrc.com/teensy41_2.jpg

    But I can't find out what these five pins are.
    These are pins that are on the back or adjacent to the SD card on other Teensies. In particular, look at the back of the Teensy 4.0. Those 5 pins are the same on 4.1, except they are in a different position.

    Starting at pin 38 (right hand side if you have the USB plug pointing up), the pins are:
    • Pin 38 (outer row pin);
    • On/off pin -- if connected to ground for something like 5 seconds, the Teensy 4.1 will turn itself off. It will turn itself back on the next time you connect it to ground for about a second or so;
    • Program pin -- alternate way to put the Teensy into program mode than pressing the button. If you connect it to ground for exactly 15 seconds (until the red LED in the front blinks), the bootloader will reload a the blink program into the Teensy that the Teensy shipped with so you can more easily reload the Teensy if something went wrong;
    • Ground pin;
    • 3.3v pin;
    • Vbat pin -- if you connect the Vbat pin to the + side of a 3v oin battery, and connect a ground pin to the - side of the battery, it will use the coin battery to keep the time in a real time clock, that you cat set the normal Teensy clock when the board starts up;
    • Pin 27 (outer row pin).
    Last edited by MichaelMeissner; 05-20-2020 at 07:16 PM.

  4. #4
    Got it! Thank you both, I didn't think to refer to previous Teensies.

  5. #5
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    3,672
    Quote Originally Posted by WMXZ View Post
    until otherwise told by Paul, I would assume the pins to read (bottom view from left to right)
    Reset, Program, GND, 3.3V, VBat
    i.e. the same as for T3.5/6
    On Teensy 4.0/4.1, it isn't reset, but on/off. See my post above. On the Teensy 3.0, 3.5, and 3.6 it was reset. On the Teensy 3.1, 3.2, and LC it is the DAC (A14 or A12) that you can use to play mono sounds.

    So to be more pedantic, in case somebody else reads the thread with the same question.

    • On the Teensy 3.0, the pins are Reset, Program, Ground, 3.3v, and Vbat;
    • On the Teensy 3.1 and 3.2, the pins are DAC (A14), Program, Ground, 3.3v, and Vbat;
    • On the Teensy 3.5 and 3.6, the pins are Reset, Program, Ground, 3.3v, and Vbat;
    • On the Teensy 4.0 and 4.1, the pins are On/off, Program, Ground, 3.3v, and Vbat;
    • On the Teensy LC, the pins are DAC (A12), Program, Ground, 3.3v, and level shifter to convert pin 17/A3 to VIN for use with WS2812B LEDs (the LC doesn't have a usable real time clock).


    The pins are at the end of the Teensy for the 3.0, 3.1, 3.2, 4.0, and LC.

    The pins are adjacent to the micro-SD card for the 3.5, 3.6, and 4.1.

    To use the real time clock on the Teensy 3.0, 3.1, or 3.2, you need to solder in a 32.768kHz crystal to the two pins on the Teensy for the crystal (see the back of the pinout card). The Teensy 3.5, 3.6, 4.0, and 4.1 have an internal crystal and you don't need to solder one.
    Last edited by MichaelMeissner; 05-20-2020 at 07:21 PM.

  6. #6
    Senior Member
    Join Date
    Jul 2014
    Posts
    2,637
    Quote Originally Posted by MichaelMeissner View Post
    On Teensy 4.0/4.1, it isn't reset, but on/off. See my post above.
    I'm aware of it, but I wanted you the pleasure to explain it in detail

Posting Permissions

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