Preventing your board from resetting on serial port opening

Most Arduino boards auto-reset when the serial port opens. This is the case with the Arduino Uno, Mega and Nano.

If you wish to prevent this auto-reset, use either one of the following methods. If none of these works for you, please have a look at the dedicated Arduino Playground article which presents other solutions.


1) Adding a 100nF capacitor

This is by far the simplest solution which should work with most of your boards. The auto-reset is triggered by the DTR line on the serial connection which goes low for a short moment just after serial port opening. To cancel the effect of the DTR line, simply plug a 100nF ceramic capacitor between the GND and RESET lines on your board.



2) Using boards which does not auto-reset

Some Arduino boards do not auto-reset when the serial port opens. This is the case of the Arduino Leonardo and Micro. You can use one of those if it fits your needs.


Was this article helpful?
0 out of 0 found this helpful