Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 10 of 10

Thread: access to usb pins on teensy 4.1

  1. #1
    Senior Member
    Join Date
    Nov 2012
    Location
    Los Angeles
    Posts
    116

    access to usb pins on teensy 4.1

    Hi all,
    Quick question/confirmation that the only access to the primary USB connection on the teensy 4.1, other than the USB micro connection, is via the 2 pads below (D+ & D-) below the USB micro connector? The teensy will be mounted to a PCB inside a case and looking to "extend" the USB connection to a socket on the case without too many sockets/connections inside the case for ease of programming/updating firmware. For example, would love to be able to use something like this:
    https://www.mouser.com/ProductDetail/530-SS-52100-001
    then connect the data and power pins in the socket directly to the teensy.

    Thanks in advance for any guidance.

    David

  2. #2
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    11,943
    There are male Micro to female USB cables - panel mount or other perhaps - PJRC used to stock one - just linked one the other day.

    That would take some room - but avoid soldering and any troubles with the T_4.1's higher 480 Mbps transfer rate.

  3. #3
    Senior Member
    Join Date
    Nov 2012
    Location
    Los Angeles
    Posts
    116
    Great. I've been looking at those, too. Just wanted to make sure the USB pins weren't broken out elsewhere on board and hiding from me
    Thanks,
    David

  4. #4
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    22,273
    The 2 small test points on the bottom side of Teensy 4.1, underneath the main USB connector, are indeed the D+ and D- signals. Teensy 4.0 and very early beta 4.1 test boards didn't have those 2 pads, due to concern for the 480 Mbit speed signal integrity. But it turned out they don't cause a problem, so they did make it onto the final Teensy 4.1 design.

    But those 2 signals are for the main USB port which is only supported in USB device mode. That SS-52100-001 connector is a USB type A female, which is only appropriate for USB host mode. You would need to connect that to the 2nd USB port, which is on the 5 through-hole pins on Teensy 4.1, or as data-only pads on the bottom of Teensy 4.0.

  5. #5
    Senior Member
    Join Date
    Nov 2012
    Location
    Los Angeles
    Posts
    116
    Hi Paul,
    Thanks for your help with this. The teensy will only be working in usb device mode for this application. Most of the communication to/from will be via RS485 and the fancy new network option you've added to the 4.1. 99% of the time the teensy won't be connected to any host via USB. This is only for the infrequent times we need to update the firmware but don't want to open the case...pretty much an extender from the edge of the case to the micro usb socket on the t4.1.
    Not sure that clarifies anything or not
    Thanks,
    David

  6. #6
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    11,943
    Quote Originally Posted by virtualdave View Post
    Great. I've been looking at those, too. Just wanted to make sure the USB pins weren't broken out elsewhere on board and hiding from me
    Thanks,
    David
    As Paul noted - the Device USB pads are there on T_4.1 - but an adapter like this discontinued PJRC part would be nice if you find the desired type that fits - with no soldering.

  7. #7
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    22,273
    Quote Originally Posted by virtualdave View Post
    Not sure that clarifies anything or not
    Indeed that does give a better picture of what you're trying to accomplish.

    But just because you don't normally need the main USB connector for device mode isn't going to magically make software appear to run it in host mode. The only software support for the main port is USB device mode. It is theoretically possible to create software to run the main port in host mode, if you're feeling like climbing a steep hill...

    We do have USB host support for the 2nd port. And the 2nd port is easily available from either side of the PCB on 5 though-hole pins. So I'm a little confused about why you wouldn't want to just use the 2nd USB port?

  8. #8
    Senior Member
    Join Date
    Nov 2012
    Location
    Los Angeles
    Posts
    116
    Sorry, I feel like I'm confusing myself. I don't need the teensy run as a USB host. I only need need the usb connection to upload new firmware from a laptop as needed/after the device is "in the field". I've also been reading here on the forum how to update the firmware via network/other means instead of USB, just as an alternative.

    The panel mount USB-B cable looks to be a viable option.

    Thank you all again,
    David

  9. #9
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    22,273
    Do not use that SS-52100-001 connector.

    This connector is used for USB host mode only!

    Click image for larger version. 

Name:	SS-52100-001.jpg 
Views:	2 
Size:	16.2 KB 
ID:	20610

  10. #10
    Senior Member
    Join Date
    Nov 2012
    Location
    Los Angeles
    Posts
    116
    Copy that!
    Thanks!
    David

Posting Permissions

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