arduino nano reset after serial port opened - turn off

Hi,
im making a program that will communicate with computer via UART, i using arduino nano (with CH340G serial chip + driver on PC) and i create an program on pc that will send data and vice versa.
This all works fine, but when i open the corresponding port on pc the arduino will resets and for my project i want to turn it off, if that is option. I found that it (possibly) can help 120ohm resistor or 10u cap but that didnt work for me, and ideas?
Thanks

For serial loading of sketches, Arduino looks to see if a new sketch is waiting to be uploaded on reset. Reset is of course triggered by power off/on, it is also triggered by the DTR signal received (or not) on the USB port. To connect with the unit, use a terminal emulator that gives you control over DTR and turn it off, or through the serial code in your own app turn it off yourself.

The info I have seen is not a 10uF capacitor, but a 0.1uF capacitor in place or R6 (remove R6, put in capacitor).

blh64:
The info I have seen is not a 10uF capacitor, but a 0.1uF capacitor in place or R6 (remove R6, put in capacitor).

That method works and is useful for a unit that goes into production. For continued tinkering however, you've just removed your ability to load sketches without physically effecting reset within 200ms of power up. When you go that route, you may as well remove the bootloader and then do everything via ICSP.

I use this circuit with a Nano, switch one way, normal, other, 100nF capacitor is connected to reset pin, preventing reset on serial connect.
cap-n-sw.png