Hi there !
I’m working on a small software, nothing complicated.
I have button from ofxDatGui. When I press the button, it trigger myserial.writeByte(). And of course mySerial is an instance of ofSerial.
Thank you in advance for any help 
My setup
- System is virtualized over VMWare, host under Windows 10
- Ubuntu 18.04
- OF cloned and compiled from GITHUB
- Branch Stable
- QT Creator 4.6.1
- Serial adapter : CP2102 - Silicon Labs
see here :
ofApp.h :
class ofApp : public ofBaseApp{
public:
...
ofSerial mySerial;
...
};
ofApp.cpp :
void ofApp::setup(){
...
mySerial.setup("/dev/ttyUSB0", 115200);
unsigned char myByte = 225;
bool byteWasWritten = mySerial.writeByte(myByte);
if ( !byteWasWritten )
ofLog(OF_LOG_ERROR, "Byte was not written to serial port");
...
}
...
void ofApp::onButtonEvent(ofxDatGuiButtonEvent e)
{
printf("Hit button");
cout << e.target->getName() << endl;
bool byteWasWritten = mySerial.writeByte('t');
if( !byteWasWritten)
printf("byte was not written to serial port");
}
- Nothing appear on my serial port (I have an oscilloscope connected to my Tx serial adapter.
- ( writeByte(‘t’) returned True ) and I don’t see “Byte was not written to serial port” message in terminal.
- Strange thing : mySerial.isInitialized(); return 0 when I try to put it in a while() loop before writeByte(). So everything is blocked. Removed.
- My user is part of dialout user group.
- I tried to launch my app in root, changed nothing.
i tried the Example/oFserial compile, run, it find my /dev/ttyUSB0 but can’t writeByte neither.
BUT
When I use CuteCom software (not in root) I can send data on my serialPort and I can see it on my scope.
As I said, thank you for your help !
EDIT :
Tested with Arduino plugged and this way create a serial device. This device is also /dev/ttyUSB0. Same behaviors… Not working in OF but work in cuteCom. So problem seems not to be in the usb serial adapter or device driver.
EDIT :
Very strange behaviors : If i launch serialExample, it does not work as usual. If i launch cuteCom it work as usual. But if I launch the both at the same time, serialExample try to open the com port : success, cuteCom open : success, and now serialExample si working as expected. Click make serial frames visible on my scope…