Teensy 4.1 issues with serial ports

hbear

Member
I'm not sure where to post this but I'm having a problem with my Teensy 4.1's that I've seen mentioned here before. I cannot launch scripts where the Arduino monitor window I use to direct program flow doesn't just sit flashing from white to dull white. I looked at the Device Manager and see an icon which appears to flash in sync with the monitor. If I remove the usb to the Teensy 4.1 the icon in the Device manager disappears, indicating that it's the Teensy 4.1 which is associated with the issue. Same code runs fine on my 3.6's, and fails in this way with my 4.1's. I have a screenshot of the device manager, which I'll attach. Could you direct me to the proper forum to post the problem?
Thanks
 

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Here seems good - it will be seen.
Details presented so far don't describe an issue noted before. Added detail needed.
Almost seems the Teensy going offline or having trouble staying connected.
Start with a simple Blin kand add USB output and observe that to work. Perhaps add CrashReport and test waiting for input to the Teensy reading and printing the characters.
 
Here seems good - it will be seen.
Details presented so far don't describe an issue noted before. Added detail needed.
Almost seems the Teensy going offline or having trouble staying connected.
Start with a simple Blin kand add USB output and observe that to work. Perhaps add CrashReport and test waiting for input to the Teensy reading and printing the characters.
I will try to isolate a good example that is compact enough to be useful. I worked all day today and discovered two things. First, I should say I am working on code that talks to both an ADXL345 accelerometer (SDA1/SCL1) and an A/D converter (SDA/SCL) via I2C via the Teensy 4.1's wire library ports on teensy. Today I hooked the accelerometer alone to SCL/SDA and was able to get a test script reading data successfully with the 4.1. My ADC converter is an ADC1115 using the library written by terryjmeyers (ADS1115-lite-master). I am beginning to suspect that something in the library may be creating an issue with ADC1115 when it comes to the teensy 4.1.
I will investigate what happens when I substitute the ADS1115 with a Gravitech I2CADC tomorrow, to see if it can operate in the presence of the ADXL345, and will post what I find.
I should add that I have been working with the ADXL345 and the ADS1115 on the same project (identical board layout as to components to generate and record signals) with a Teensy 3.5 and have never run into a communications failure during either the upload or running the script. The problem developed only in the presence of the 4.1. Also, loading the same 4.1 with the blink test, for example works just fine. I think the processor is OK.
The symptom is that after upload, when you open the monitor, the monitor simply "blinks", switching from a white blank screen to a fainter white screen, with no text at all (the script is effusive with Serial print statements), as if something is continuously attempting to establish the USB/Serial connection.
I've read your responses on many occasions, and I very much appreciate your response. I'll try to get you something with an example of the code involved tomorrow.
 
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T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.
the monitor simply "blinks", switching from a white blank screen to a fainter white screen, with no text at all (the script is effusive with Serial print statements),
 
I strongly suspect this is yet another case of issues with static initialisation of Wire objects, as discussed in this thread. We seem to have lost the (widely ignored) exhortation at the top of every page to "Show Your Code" and "What Version Of Teensyduino And IDE Are You Using?", so just throwing darts here, but ... you should try Teensyduino 1.59 beta 3.
 
I strongly suspect this is yet another case of issues with static initialisation of Wire objects, as discussed in this thread. We seem to have lost the (widely ignored) exhortation at the top of every page to "Show Your Code" and "What Version Of Teensyduino And IDE Are You Using?", so just throwing darts here, but ... you should try Teensyduino 1.59 beta 3.
T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.
T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.

T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.
As to your reply and one from h4yn0nnym0u5e, as soon as I have a code example which highlights the problem but which is less voluminous than the one I've been running with the T3.6 (which works) I will send the result including code, hopefully later today.
With some luck, the Teensy upgrade might do the trick.
Again thanks.
T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.
 
I strongly suspect this is yet another case of issues with static initialisation of Wire objects, as discussed in this thread. We seem to have lost the (widely ignored) exhortation at the top of every page to "Show Your Code" and "What Version Of Teensyduino And IDE Are You Using?", so just throwing darts here, but ... you should try Teensyduino 1.59 beta 3.
A question: I have two 1.8.19/1.58 installations - one in the ProgramFiles86 folder, and an IDEPortable installation on an external drive. How do I reinstall with the new Teensyduino (1.59 beta3)? Do I need to peform any kind of uninstall in these two areas, or do I simply run the installer - TeensyduinoInstall.exe on the ProgramFiles86 Arduino installation and Teensyduino.exe on the portable? Not sure what the proper procedure is in this case.

As to your reply and one from defragster, as soon as I have a code example which highlights the problem but which is less voluminous than the one I've been running with the T3.6 (which works) I will send the result including code, hopefully later today.
With some luck, the Teensyduino upgrade might do the trick.

Again thanks.
 
T_4.x not only runs much faster than a T_3.6 - but the USB connection is 480Mbps instead of 12Mbps and can overwhelm a PC. Be sure to select Teensy_Ports as it provides a PJRC optimized SerMon that can better keep up.
As to your reply and one from defragster, as soon as I have a code example which highlights the problem but which is less voluminous than the one I've been running with the T3.6 (which works) I will send the result including code, hopefully later today.

With some luck, the Teensy upgrade might do the trick.

Again thanks.
 
Just install as normal, there’s no need to uninstall. If I recall correctly, there’s a point where the installer offers you a target folder, which defaults to the Program Files x86 path - that’ll work for one of your installations, and you’ll have to navigate to your portable install folder to do the other one. It shouldn’t let you proceed unless the target folder makes sense.

You should only need to do one install to test, of course.
 
Just install as normal, there’s no need to uninstall. If I recall correctly, there’s a point where the installer offers you a target folder, which defaults to the Program Files x86 path - that’ll work for one of your installations, and you’ll have to navigate to your portable install folder to do the other one. It shouldn’t let you proceed unless the target folder makes sense.

You should only need to do one install to test, of course.
Thanks, I'll give it a try. It is interesting that the peripheral I was able to succeed in using with the T4.1 is the ADXL345 accelerometer, which only requires Wire1 to initialize and run on I2C, while the other, an ADS1115 requires its own library to connect to I2C via the Wire library. Anyway, first I'm going to give the original code a shot following the reinstall of Teensyduino.
 
I tried my troubled Board prototype with the T4.1 plus the two I2C devices after installing the new Teensyduino and from the first test, it works!
I shall be running the board through a couple other scenarios and if all is Ok, I will post a description of the symptoms which caused me to post this weekend along with the results of the Teensyduino update to 1.59 beta 3.
Obviously, I would not have solved this problem on my own!
Thanks for the replies. Greatly appreciated.
 
I had encountered an issue with the USB connection of my Teensy 4.1 which manifested as a blinking Monitor window following the upload, during which no activity occurred in the monitor window. Today I updated with the Teensyduino (1.59 beta 3) and tested my Teensy 4.1 project on my Win 10 and Win 11 laptops, and the code now runs normally with no hiccups. I want to thank the members here who responded to my call for help. Back in business and many thanks.
 
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