MountainView
Member
I've been doing some tests using a Teensy 3.2 and OctoWS2811 to drive LEDs. I had the combined boards sitting on top of a 5V power supply (Meanwell NES-100-5) and it worked fine like this for a long time. Then I unplugged the power supply and replugged it and the Teensy stopped working correctly. When it was plugged in the /dev/ttyACM0 device was not present and there was no way to communicate with it. However, I found that after unplugging it, leaving it alone for a couple hours and plugging it in again, /dev/ttyACM0 would appear again once it was plugged in and the Teensy would appear in lsusb, but only for a few minutes. After being plugged in for 3-4 minutes, /dev/ttyACM0 was gone again. I tried unplugging and replugging it again and /dev/ttyACM0 reappeared, but this time it lasted for less than a minute before disappearing.
Apparently, the board now needs to have a period of downtime before the USB serial interface becomes available again. It's as if some charge has built up within the board that prevents /dev/ttyACM0 from working, and it dissipates when the board is unplugged but rapidly builds up again once it's plugged in. The USB communication with the Arduino IDE is still working, I can press the button on the Teensy and I see feedback in the IDE's console log. If this is electrical damage to the board, it seems to have strangely specific effects. Has anyone heard of anything like this before? I would think that if the board got hit by an electric discharge it just wouldn't work at all. Could something else be the cause?
I've attached the console logs of two times I pressed the button. At first you can see the "address" : "/dev/ttyACM0" property but it's gone after the first restart of the board, replaced by "usb1/1-1." Thanks for any advice.
First button press:
Second button press:
Apparently, the board now needs to have a period of downtime before the USB serial interface becomes available again. It's as if some charge has built up within the board that prevents /dev/ttyACM0 from working, and it dissipates when the board is unplugged but rapidly builds up again once it's plugged in. The USB communication with the Arduino IDE is still working, I can press the button on the Teensy and I see feedback in the IDE's console log. If this is electrical damage to the board, it seems to have strangely specific effects. Has anyone heard of anything like this before? I would think that if the board got hit by an electric discharge it just wouldn't work at all. Could something else be the cause?
I've attached the console logs of two times I pressed the button. At first you can see the "address" : "/dev/ttyACM0" property but it's gone after the first restart of the board, replaced by "usb1/1-1." Thanks for any advice.
First button press:
Code:
2025-03-22T18:54:38.378Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"/dev/ttyACM0","label":"","protocol":"serial","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:54:38.386Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"usb1/1-1","label":"","protocol":"teensy","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.402Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.405Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.406Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:54:39.409Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/096 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""Second button press:
Code:
2025-03-22T18:55:45.000Z discovery-log INFO {"eventType":"remove","port":{"matchingBoardsList":[],"port":{"address":"usb1/1-1","label":"","protocol":"teensy","protocolLabel":"","propertiesMap":[],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.215Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.218Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.218Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}
2025-03-22T18:55:46.221Z discovery-log INFO {"eventType":"add","port":{"matchingBoardsList":[{"name":"Teensy 3.2 / 3.1","fqbn":"teensy:avr:teensy31","isHidden":false}],"port":{"address":"usb1/1-1","label":"/dev/bus/usb/001/097 Bootloader","protocol":"teensy","protocolLabel":"Teensy Ports","propertiesMap":[["modelID","0x21"],["name","Teensy 3.2"]],"hardwareId":""}},"error":""}