Teensy 4.1 not recognised in Arduino anymore

S

stefanmader1984

Member
I had 2 different Teensys connected to the pc.
While uploading Code to one of them, something went wrong. The connected Teensy 4.1 has been screwed up. I can't upload code to it anymore, it isn't recognised by Arduino IDE anymore.

It shows up in Windows as a generic hid device in device manager but doesn't get a COM port.

is there anything i can do to rescue the Teensy 4.1?
maybe flash a bootloader or something? i do have a stk500 programmer available.
 

Teensy® 4.1

www.pjrc.com www.pjrc.com

Memory Wipe & LED Blink Restore
Teensy 4.1 will fully erase its non-volatile memory and return the flash memory to a simple LED blink program if the program button is held between 13 to 17 seconds. The red LED flashes briefly at the beginning of this time window. During flash erase, the red LED is on bright. When completed, Teensy 4.1 will automatically reboot and run the LED blink program, causing the orange LED to blink slowly.
 
stefanmader1984 said:
It shows up in Windows as a generic hid device in device manager but doesn't get a COM port.
Click to expand...

This is normal. By default Teensy uses HID protocol, not Serial. You will not see a COM port on Windows (or /dev/ttyACM on Liniux or /dev/cu.usbmodem on MacOS) when Teensy is running with its default HID communication.

It only becomes USB Serial when running a user program, and only if Tools > USB Type was set to one of the choices with Serial when that program was compiled.

If you press the button for 15 seconds, and wait for the long/slow erase (takes about 1-2 minutes) when Teensy reboots, it will run a LED blink compiled as RawHID. You will **NOT** see a COM port. Please understand the correct expected result after this restore process is HID only. The same true with every brand new Teensy. They all ship with the LED blink compiled using RawHID, not Serial.
 
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