Arduino M0 changing port when opening Serial Monitor (Linux)

Development Tools IDE 1.x
1

Hello,

I have a weird problem and have no luck so far.
Using the arduino.org IDE, I upload a very simple sketch (Blink) with some serial outputs to a Arduino M0.
When I initially connect with the board, ttyACM0 is available under Tools > Port. I click it and then upload the code to the board. All goes well until I try to get serial output. As soon as I open the Serial Monitor, the board resets itself, suddenly is on port ttyACM1 and I have no output. Then I have to reopen the Serial Monitor to view the output.
When using the reset button, the port changes back to ttyACM0.

  • I have followed the steps on this page: Arduino - Home

  • I've tried different USB cables, ports and computers

Anybody have any idea what to try next? Is it something in Ubuntu or the IDE?

This is the code:

void setup() {  
  while(!SerialUSB);  
  SerialUSB.begin(9600);
  SerialUSB.println(F("[ SETUP  ] Start"));

  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH); 
  delay(250);             
  digitalWrite(13, LOW);  
  delay(1000);              
}
2

(deleted)

3

So you can't ask questions about an .org board on the .cc forum? :confused:

4

Of course you can but both sides don't do all the same boards and that is a very important fact in this case.

Some .CC boards are not available on .ORG and vice versa.

However support for a board that many .CC members don't know much about might often be better supported on .ORG.

Same reason you don't see much support for Adafruits boards here or some of the other more obscure custom boards.

5

I thought the Zero and M0 were very much alike, that's why I asked here.

It has been brought to my attention that the port switching somehow is a "feature" of the M0 and has to be dealt with by the OS. I wish I could explain it more for future reference but I still don't see the reason it could be handy. It's workable to open Serial Monitor, switch ports, open Serial Monitor, switch ports and open Serial Monitor again to get the output, although it's not preferred this way ofcourse :smiley:

Thank you for taking the time to reply :wink:

6

SnakeMastr805:
I thought the Zero and M0 were very much alike

They have different & incompatible bootloaders, even though the hardware is nearly identical.

that's why I asked here.

Maybe your choice of forums also has something to do with the scale & quality of community support.