USB serial port works but doesn't - any ideas? (solved)

Projects Interfacing w/ Software on the Computer
1

I have a adafruit feather M0 board running some very basic serial port code. Just repeatedly transmit "hello world".

All this works in the Arduino IDE serial port monitor.

If I bootload the processor and use a 3rd party serial program (I've tried several, Termite, Terminal, QT serial port example). I cannot view the serial coming from the feather to the windows 10 machine. I can transmit data from Window to the M0 and it does understand it (code to receive a character and change the blink rate of the led). (so sort of working)

Now here's the weird thing. If I bootload then check the serial with the IDE serial monitor then close the IDE serial monitor and open one of the 3rd party terminal programs - it works.

In summary - it works fine with the IDE serial monitor but not with a 3rd party terminal program - unless I first run the IDE serial monitor and then everything is fine.

Any ideas?

2

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3

In your terminal programs, try turning off Hardware Flow control. And if an option exists, set DTR high or active.

4

Thank you gbafamily for the DTR clue. If I manually set (or include after the serial open in Qt) the DTR to true - then I start seeing all of the serial coming from the Arduio to the host windows machine.