Arduino UNO un-responsive (no USB "serial port")

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ac2ev
 
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Arduino UNO un-responsive (no USB "serial port")

Post by ac2ev »

I downloaded some sample code to my Uno that drives an IR LED. I've examined the code and it doesn't do anything out of the ordinary. It does disable interrupts while pulsing the IR LED to maintain proper timing but other then that it's pretty straight forward.

But now I cannot get any computer to recognize my UNO. I've tried Linux, XP, Win7 and a Win8 box.

When I plug it in to my USB port the power LED comes on and the IR LED lights up (monitor through a camera w/o IR filter). So I believe the ATMega chip is good. Is there any other method that I can use to communicate, to figure out if the onboard USB/serial port is functioning?

I've tried various methods of plugging/unplugging along with the reset button. The computer never recognizes the device is there. I don't get the da-boink sound or icon. Nothing shoes up in device manager on windows and nothing is reported by the USB daemon in Linux.

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by adafruit_support_rick »

What happens if you disconnect the IR LED?

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ac2ev
 
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Re: Arduino UNO un-responsive (no USB "serial port")

Post by ac2ev »

Still no response.

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by adafruit_support_rick »

Have you tried a different USB cable?

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ac2ev
 
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Re: Arduino UNO un-responsive (no USB "serial port")

Post by ac2ev »

Yes. I've gone through all the normal stuff. When I plug it in the Power LED lights green and the yellow LED (connected to pin 13) blink 4 or 5 times very fast but I see nothing on the TX or RX LEDs. I think I may disabled or damaged the USB to serial chip somehow. It's an odd one.

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by adafruit_support_rick »

It does sound like it's toasted. IR LEDs take a lot of current. How did you have it connected?

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by ac2ev »

Through a current limiting resistor and then a couple of transistors like the tv-b-gone. Although the the transistor arrangement had a wiring error causing a brownout. No smoke but maybe enough to damage the chip.

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by ac2ev »

SUCCESS!

Did a little more investigation on the internet and found a solution!
Apparently it isn't uncommon for the Uno serial chip to "lose it's mind".

Following the instructions here worked:
https://www.virtuabotix.com/how-to-cure ... -syndrome/

I used the .hex file from this site:
https://github.com/arduino/Arduino/blob ... al-uno.hex

You may have a copy on your local pc here:
C:\Users\<username>\Documents\Arduino\source\arduino-1.0.1\hardware\arduino\firmwares\arduino-usbserial

Once I cycled power to the Arduino the serial port showed up. I then loaded the blink program to verify the Uno and it's looks like everything is working again.

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Re: Arduino UNO un-responsive (no USB "serial port")

Post by adafruit_support_rick »

Excellent! Thanks for the links!

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