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Topic: Arduino Nano resets every 30 seconds (Read 1 time) previous topic - next topic

gabrieleorio

I read this in the product page of Arduino Nano on Arduino website: maybe it can be of some help, but I don't understand exactly what it means.

Automatic (Software) Reset
Rather then requiring a physical press of the reset button before an upload, the Arduino Nano is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the FT232RL is connected to the reset line of the ATmega168 or ATmega328 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.
This setup has other implications. When the Nano is connected to either a computer running Mac OS X or Linux, it resets each time a connection is made to it from software (via USB). For the following half-second or so, the bootloader is running on the Nano. While it is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few bytes of data sent to the board after a connection is opened. If a sketch running on the board receives one-time configuration or other data when it first starts, make sure that the software with which it communicates waits a second after opening the connection and before sending this data.
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Grumpy_Mike

OK what system are you running it from?
Some Linux systems keep opening up the serial port and this resets the arduino automatically.

Try opening up the serial monitor, that will hold open the serial port drivers. If that stops it resetting then that is the problem.

gabrieleorio

Dear Grumpy_Mike that works!!!!

Keeping the serial monitor open eliminates the problems and the board doesn't reset anymore.

Is there a way to avoid it without keeping the serial monitor open? (I'm running windows 7 by the way)

I guess that when I'll be supplying my board with an external voltage different from the USB the problem won't appear, right?

Thank you very much sincerely!

Grumpy_Mike

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I guess that when I'll be supplying my board with an external voltage different from the USB the problem won't appear, right?

That's right.

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Is there a way to avoid it without keeping the serial monitor open?

I don't know, that is a windows question and I am a Mac man.


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