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Topic: Arduino Nano USB port blows -  (Read 2136 times) previous topic - next topic

ewholz

Hello,

I am trying to use the Arduino Nano, Rev 3 atm328.  I am popping the usb ports on these like popcorn.
I am getting tired of buying new ones!  Is there some way to repair the USB port?  Can the ISP pins be used to program the device?

I am NOT abusing the device.  The first time this happened, I had the device powered off, but installed on the breadboard - there are connections to various pins, including the +5 v out, etc - the breadboard was not powered up.  I am using a windows XP laptop, and it is turned on - I connected the USB cable to the Nano usb port, and saw a message on the laptop screen about a USB port being "overloaded".  I could no longer program the Nano.  I removed the Nano from the breadboard, and tried it again, - no dice the USB port did not work.

I bought some new Nanos (from Gravitech) - left the new Nano out of the circuit, and program loaded ok.  Used device for awhile.  Then needed to reprogram it - this time left it in the breadboard, but with the power on the board - so the chip and circuit was powered up (like using the Uno, with a 9v power connected, etc)  Attempted to load the new program in the Nano - no luck, get a bunch of sync errors and the program will not upload - I am run the program, and monitor the serial out - and the program does output its serial data, but no input!

Any idea what to do here?  I pulled out a backup Nano - and it works fine, loaded the program, but did not have the device in the circuit, etc.  The computer detected the Nano right away.

The problem here is -once the chip is in production, and soldered in to the PCB - just suppose I want to re-program it!  I do not want to blow the USB.  Any suggestions or workarounds?

thanks ewholz.

runaway_pancake

A jumper block ("shunt"), or as many as necessary, or a switch to disconnect those high-demand 5V circuits.
"Who is like unto the beast? who is able to make war with him?"
When all else fails, check your wiring!

CrossRoads

Post your circuit - let's see if we can figure out what is making them break. Maybe drawing too much current on the 3.3V output for example.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Paul__B

#3
Apr 18, 2015, 12:15 pm Last Edit: Apr 18, 2015, 12:27 pm by Paul__B
Clearly the problem is not with the Nano boards, but with your circuit.  You are doing something wrong.

That much we can discern from your description.  In the absence of complete detail (and a photograph) of your setup, no further advice is relevant.  Clearly there is no point pursuing the project until you clearly understand what it is.

I might however add that you need to detail what "blown" means in this context?  The Nano does not contain a polyfuse which takes a number of minutes(?) to recover but has a MBR0520 Schottky diode between the USB power and the 5V connection.  This is rated at ½ Amp so it should be difficult to burn out, but I suppose possible.  You need to test this, it should not be difficult to repair.

runaway_pancake

#4
Apr 18, 2015, 03:45 pm Last Edit: Apr 18, 2015, 03:46 pm by Runaway Pancake
I slipped up and whacked that diode on one of mine.
It failed into a resistive state, so it "worked" either way, but no longer functioned as a diode (steering or otherwise) - so if it was connected to Vusb while powered up, too, there could have been less than unconfined joy as a result.
(Can't remember what it was, but once I plugged in the USB, there was sizzling and that smell and I was aghast that I'd done such a thing.)

> > > Replacing the diode was a cinch.
"Who is like unto the beast? who is able to make war with him?"
When all else fails, check your wiring!

ewholz

#5
Apr 19, 2015, 11:49 pm Last Edit: Apr 19, 2015, 11:51 pm by ewholz
Hello All,

Thanks for the response on this.  I actually do not think I am doing anything wrong, as the exact same circuit and application is programmed into an Arduino Uno - and I can program it whether or not I have the input voltage applied to the circuit (main voltage is from 12-14 VDC) and whether or not the board is in the circuit or not.

I have uploaded my Eagle schematic for examination,

Thanks Again, as always open for input!  Sorry the schematic is an image - not the actually .sch file from the eagle s/w.

ewholz

Hello Again,

Clarification of "blown" - by that term I mean that when the Nano is connected to the USB cable, it will not upload the code to the Nano - the IDE fails to load the code, with sync errors.  The RxTx lights do not blink as they do during a normal upload.

The USB does send data from the Nano to my PC! (I have a serial output of various data, that can be checked, etc)

thanks again,

ewholz

Paul__B

I am a bit curious as to what the connections to the right of your diagram are?

It would be relevant to know what is supplying each of the power connections on your diagram.

And a photo might give some hints.

The "attachment" system is not working properly (if at all) on this forum at present, much preferable if diagrams and pictures are uploaded to imgur and linked as such in the text. :(

Clarification of "blown" - by that term I mean that when the Nano is connected to the USB cable, it will not upload the code to the Nano - the IDE fails to load the code, with sync errors.  The RxTx lights do not blink as they do during a normal upload.

The USB does send data from the Nano to my PC! (I have a serial output of various data, that can be checked, etc)
So the USB port is in fact entirely functional, but something else is happening.  I note you illustrate a pull-up resistor on the reset terminal.  Why?

ewholz

Hello Paul__B et al,

thanks for reply:  Responses:

I am a bit curious as to what the connections to the right of your diagram are?

Those go to a brushless DC motor - they are windings and hall sensors in the motor.

It would be relevant to know what is supplying each of the power connections on your diagram.

All the power comes from a 12 to 14 volt battery, the Nano is powered at its VIN pin, and the other device (the DC motor controller) gets the same voltage on its pin 4.

I am using the +5V from the Nano to power pull-up and an encoder.

And a photo might give some hints.

The "attachment" system is not working properly (if at all) on this forum at present, much preferable if diagrams and pictures are uploaded to imgur and linked as such in the text. :(


So the USB port is in fact entirely functional, but something else is happening.  I note you illustrate a pull-up resistor on the reset terminal.  Why?

I added a pull up resistor to the RST circuit to "emulate" the circuit on the Nano - the reset button on the board grounds the pin on the Nano (pin 29 RESET), pin 29 has a pull-up resistor connected to it.
I am using the RESET button on the Adafruit LCD display.

I apologize for image.  I can post on smug mug if required, and add link.  I prefer not to create yet another login for imgur.

A photo would not help - the circuitry is all on a breadboard now, using jumper wires, etc.  The current draw on the +5 out (Nano pin for +5) is less than 50ma.

Thanks Again,

ewholz

Paul__B

From memory, your diagram showed no connection between the Nano reset and any Adafruit display.

I suspect you will find that if you get rid of the spurious resistor and make no connection to the reset pin on the Nano, it will program correctly.

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