Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 12 of 12

Thread: 4.0 USB pads? and optional sizes

  1. #1
    Senior Member
    Join Date
    Jul 2017
    Posts
    103

    4.0 USB pads? and optional sizes

    Hi, im curious if the 4.0 has any way to tap into the USB port, on the 3.x models you have pads and the 3.6 has pins for the USB host as well, this is great if you want to put it on a custom board with a full size USB port rather than micro usb (ive broken so many). So im wondering if there's a way to tap into it or if there will be a future model that would include that?

    Also will there be a teensy 3.6 compatible model with easier access to pins and an SD card built in?

  2. #2
    Senior Member
    Join Date
    Jun 2018
    Location
    USA
    Posts
    173
    I agree, microusb is easily broken. I prefer 5 pin USB headers, so I can connect my own USB port. Pro audio gear still uses USB B for devices. It's much larger and robust. So I would likely try to remap the USB. Even with micro USB to USB B chassis cables.

  3. #3
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    24,454
    Still too early to talk about whatever the next Teensy model may be...

    On Teensy 4.0, there are no extra bottom side pads to access the same signals that go to the USB connector. This was done on earlier Teensy 3.x boards with 12 Mbit/sec USB. Because Teensy 4.0 has 480 Mbit/sec USB, that sort of PCB routing is too risky for causing signal quality problems.

  4. #4
    Senior Member
    Join Date
    Jun 2018
    Location
    USA
    Posts
    173
    On Teensy 4.0, there are no extra bottom side pads to access the same signals that go to the USB connector. This was done on earlier Teensy 3.x boards with 12 Mbit/sec USB. Because Teensy 4.0 has 480 Mbit/sec USB, that sort of PCB routing is too risky for causing signal quality problems.
    Paul, can you please confirm that the exposed USB pins (other than the one hard soldered on) can be configured to effectively operate the same way? Are the two USB pins interchangeable? Can they both work the same way? Or are there differences between the two USB ports?

  5. #5
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    24,454
    Hardware-wise, the 2 ports are almost identical.

    Software-wise, the main port is supported in USB device mode only, and the 2nd port (pads on the bottom side) is supported in USB host mode only.

  6. #6
    Junior Member
    Join Date
    Aug 2019
    Posts
    1
    Quote Originally Posted by PaulStoffregen View Post
    Hardware-wise, the 2 ports are almost identical.

    Software-wise, the main port is supported in USB device mode only, and the 2nd port (pads on the bottom side) is supported in USB host mode only.
    Does that mean that if main port is out of order there is no way to use the 2nd port instead?

  7. #7
    Senior Member+ Frank B's Avatar
    Join Date
    Apr 2014
    Location
    Germany
    Posts
    8,576
    Quote Originally Posted by Igor D View Post
    Does that mean that if main port is out of order there is no way to use the 2nd port instead?
    Yes, exactly.

  8. #8
    Junior Member
    Join Date
    Jun 2016
    Location
    Melbourne Australia
    Posts
    10
    Quote Originally Posted by PaulStoffregen View Post
    Hardware-wise, the 2 ports are almost identical.

    Software-wise, the main port is supported in USB device mode only, and the 2nd port (pads on the bottom side) is supported in USB host mode only.
    So presumably it should be possible to change the software to setup the second USB port to operate in device mode ?

    [ For use as an embedded controller I'm interested in wiring the second port to a more robust USB female connector such as mini-USB or USB-B, and using that to communicate with the host computer. ]

  9. #9
    Senior Member
    Join Date
    Jul 2014
    Posts
    3,246
    Quote Originally Posted by Graeme Gill View Post
    So presumably it should be possible to change the software to setup the second USB port to operate in device mode ?

    [ For use as an embedded controller I'm interested in wiring the second port to a more robust USB female connector such as mini-USB or USB-B, and using that to communicate with the host computer. ]
    Yes, that is possible and is rather straight forward.
    HOWEVER, you cannot use the 2nd USB port to program Teensy, that can only be done via 1st USB port. (Ignoring JTAG,etc)

  10. #10
    Senior Member+ Frank B's Avatar
    Join Date
    Apr 2014
    Location
    Germany
    Posts
    8,576
    Quote Originally Posted by Graeme Gill View Post
    So presumably it should be possible to change the software to setup the second USB port to operate in device mode ?

    [ For use as an embedded controller I'm interested in wiring the second port to a more robust USB female connector such as mini-USB or USB-B, and using that to communicate with the host computer. ]
    Use of a simple adapter cable costs 5$ and saves countless hours

  11. #11
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    24,454
    Indeed, just buy this and pour only a tiny fraction of that software work into building a sturdy box or frame to mount that sturdy B connector.

    https://www.adafruit.com/product/937

    Click image for larger version. 

Name:	937-04.jpg 
Views:	9 
Size:	128.9 KB 
ID:	24830

  12. #12
    Junior Member
    Join Date
    Jun 2016
    Location
    Melbourne Australia
    Posts
    10
    Quote Originally Posted by WMXZ View Post
    Yes, that is possible and is rather straight forward.
    HOWEVER, you cannot use the 2nd USB port to program Teensy, that can only be done via 1st USB port. (Ignoring JTAG,etc)
    Thanks - yes, I was assuming that the second port couldn't be used for programming, short of writing a custom loader of some description that would have to depend on some unchanging piece of code, or would have to ping-pong such updates.

Posting Permissions

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