[SOLVED] Arduino disappears from "System report" after few seconds on MAC

Using Arduino IDE 1.x
1

Hi,

I have trouble with Arduino Leonardo. When I plug the USB cable, Arduino disappears from "System report" after few seconds. Always it looks the same after disconnecting. I tried restart the system also, even changed the cable, or Arduino board. It seems like Arduino is visible by the system only when it is bootloading - when L led is blinking. When L led goes off Arduino disappears from the system.

And of course there is no tty.usbmodem in serial port settings after that few seconds because of that - which implies that I can't load my program to the chip.

This issue is the same on two separated brand new original Arduino Leonardo. Some time ago everything was ok, but suddenly ok was over.

How can I solve it?

2

For it to be visible after bootloading you need to open a Serial connection. Otherwise the USB interface has not been commanded to make itself visible.

This behaviour is expected.

3

:slight_smile: Thank you, you reminded me, that Arduino is able to uploading on it only when it is on bootloading state. But, earlier, autoreset happened automaticaly, when I was initiating upload.

Anyway, I did reset manually, uploaded succesfully my program, and now i know, that some trouble is in my code that prevents me from autoreseting it on upload. I have to figure it out.

Thank you!

4

My problem was exactly in my wrong code:
char* buffer;
dtostrf(floatVal, 3, 1, buffer);

It completely blocked RX port in Arduino.

I changed to:
char buffer[5];
dtostrf(floatVal, 3, 1, buffer);

And now is fine.

5

Sounds like it crashed the Arduino.