Arduino Uno R3 - tx/rx leds don't blink anymore

Development Tools IDE 1.x
1

Hi
My setup : Macbook Pro 2.4Ghz Intel Core 2 duo, RAM 4Go, OSX.6.8, Arduino Uno R3

The first tries were perfectly all right. When plugged the Uno, the OS asked for what to do with the new device. I said OK, then the device could be seen in the network prefs list. Then the tests went well with the Arduino IDE, blink test, serial test, uploaded and working successfully. Then I launched some Max patches Arduino2Max and Maxuino. Nothing happened, but may be I was missing something. Then I tried some other things : attaching a servo, running the sweep example. Nothing happened.
Then now, the device won't show anymore wherever (no /dev/tty.usbmodem***), even tried on a PC Vista, the PC did not ask for anything on plugging the Uno.
The tx/rx transmitting LEDs don't blink anymore.
How will I be able to conquer the universe in these harsh conditions ?

Thanks,
Rodolphe

2

Look in system profiler and see if either a Uno or Atmega16u2 is listed under USB devices.

3

There is no thing such as Arduino or Atmega16u2 listed in the USB device list.

4

On my windows 7 system, I use control panel and then device manager and it appears under Ports not USB devices.

The serial port com number keeps changing around. The IDE loses track and keeps trying to talk to my mouse instead. I get into these complicated cycles of unplugging and pluging the USB cable, starting and restarting the Arduino IDE, and if it gets too difficult, rebooting the computer.
Sometimes the device manager says the arduino is COM4 but the IDE only gives me a choice of COM3.
It seems to be different every time, but always comes good eventually.

So all I can suggest is, keep trying.

5

Well, I was indeed talking about OSX, but the same is happening in Windows Vista : nothing shows up at the COM ports.

6

If no device is showing up in System Profilier or Device Manager, the atmega16u2 isn't being enumerated.

If you can replace the smt chip, you may need a new board.

7

Well, are you suggesting something is burnt and needs replacement ? Because I had the same symptoms with a brand new Arduino Fio.... Doing nothing else than just plugging it in.
..BUT the usb plug works well when plugging in a mouse.

8

The USB port on the FIO is only for power. The FIO has no on-board USB to serial chip. So of course nothing will show up when connected.

9

Oh, yes, I was a bit short on this.

So still what do you think happened to my UNO R3 ?

(no tx/rx blinking, nothing shows up in the tty.usbmodem**, just the power LED on)

Regards,

Rodolphe

10

I already said. You've damaged the ATmega16u2, which is the serial to USB interface.