I just install PlatformIO today, so I am all up-to-date on versions.
I am using a Teensy 4.1, and VSCode.
The code uploads fine, but the issue is, there is no output on the serial monitor. I have set the monitor_speed in platformio.ini to 115200 because that is what my program uses.
I have the same problem with the serial monitor.
The minimal app of maxgerhard works well.
My app uses RAW_HID with the build flag build_flags = -D USB_RAWHID
Entering this flag in the platformio.ini of the minimal app stopps the output on the console.
I don’t know the teensy nor I have a teensy board but as far as I can see, choosing USB_RAWHID also disables serial device via USB.
#2: …To use serial, make sure the Tools > USB Type menu is set to “Serial”, and understand Teensy only becomes a serial device when it runs your program built with this setting…
By setting build_flags = -D USB_RAWHID Serial via USB seems to be disabled.
That’s also shown in ArduinoIDE Settings where you have to choose between Serial and different other device types: