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

Thread: Issues with Teensy 4.1

  1. #1
    Junior Member
    Join Date
    Jul 2021
    Posts
    5

    Issues with Teensy 4.1

    Hi,
    We have been using the Teensy 4.1 for quiet some time now and we without any intervention they seem to stop working. We connected it via USB to our computer and after a while it stops working.
    We have repeatedly been facing this issue with multiple devices. Kindly let us know what we are doing wrong and how we can revive these devices if possible.

    Thanks

  2. #2
    Senior Member
    Join Date
    Nov 2012
    Posts
    1,750
    There is no way to know. You haven't posted any code and you haven't even said what it is supposed to do, nor what "stops working" actually means.
    You should reduce your code to the smallest amount which demonstrates the problem. While doing this the problem sometimes becomes obvious but if not, post your code here so that the problem can be replicated by other users.

    Pete

  3. #3
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    This might also be an issue with USB power management on the hosting computer, but without more information the only thing anyone can do is randomly guess.

  4. #4
    Junior Member
    Join Date
    Jul 2021
    Posts
    5
    The Teensy 4.1 was getting power and communicating via USB to Jetson Nano Dev Kit. It was working fine for a couple of days. Teensy was working normally for a couple of days, now it doesn't power up(LEDs don't light up, not detected as a USB device).

    The ICs close to the micro-USB port heat up, and the 3v3 pin and GND pins are short. I read up a few other threads similar to this issue.
    It is quite apparent that this Teensy is dead.

    Are there any ways to safeguard Teensy 4.1 externally when powering via USB?

  5. #5
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    I seriously doubt the Jetson over powered the usb system if it still works.

    You haven't told us what, if any, other things are attached to the Teensy that might have failed and shorted out the 3.3v supply.

  6. #6
    Junior Member
    Join Date
    Jul 2021
    Posts
    5
    There were a couple of encoders and two Pro Minis were connected to it. The pro minis were communicating via UART. The encoders were triggering interrupts on Teensy.

  7. #7
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    But to answer your question yes there are ways to electrically isolate usb devices from the host computer that provide power via an external source. Again, the Jetson is a 5 volt system - I have one - and it seems highly unlikely it was a source of lethal voltage.

    Search for "ADUM3160 usb isolator device" and you will find many choices.

  8. #8
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    If those pro minis were 5 volt... they would have introduced 5 volts directly to the Teensy pins.

  9. #9
    Junior Member
    Join Date
    Jul 2021
    Posts
    5
    The pro minis are the 3.3v version.
    This makes me wonder because the encoders are powered with 5v but they've been working fine with the teensy for quite some time for me.
    Is it possible that 5v intolerance won't damage the teensy right away, and it happens over time? I've been using these encoders for quite some time.

  10. #10
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    The encoders might well have been the source of trouble.

    As for them not damaging it right away... that doesn't seem intuitive.

    At this point, I'll draw back and see if anyone else has any input in that regard.

    However out of curiosity I'm going to set up a common encoder with 5v and see what I get on an oscilloscope. Not all encoders are the same.

  11. #11
    Junior Member
    Join Date
    Jul 2021
    Posts
    5
    Yeah as for the encoders not damaging it right away, it is counter-intuitive.

    Thanks for your help

  12. #12
    Senior Member ETMoody3's Avatar
    Join Date
    Mar 2014
    Location
    New Ulm, Mn
    Posts
    176
    Click image for larger version. 

Name:	371D9C98-E5B8-426A-9D65-6260333B8D47.jpeg 
Views:	31 
Size:	138.5 KB 
ID:	25330Click image for larger version. 

Name:	F14E1191-76AD-4BA1-841F-DCCB33166810.jpeg 
Views:	43 
Size:	88.5 KB 
ID:	25331

    Well, this is a highly available and common encoder breakout. It may not be what you are using. Some encoders I use only attach to the data pins and ground. This one asks for a supply, ground, and then gives data pins. I use these with 3.3 v on a lot of projects.

    Powered with 5 volts, encoder movements give a very fast 5 volt spike. Hopefully the attached (cheapo) oscilloscope picture is informative.

Posting Permissions

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