Connect USB without RESET (Serial Monitor)

Development Tools IDE 2.x
1

Hi all insiders,
I'm quite new in this forum but using a Controllino Mini with ARDUINO IDE 2.0 for quite a while.
In my current project, Sketch is sending Serial Monitor Output regularly (about every hour), which works fine. Command Lines in SM also work well.
HOWEVER: When I disconnect the USB for a while and reconnect, the whole Sketch starts anew.
Q: Is there any way to avoid this RESET or do I have to have the USB connected at all times? (Which would be a mayor drawback!)
Thanks for any help!
Gloebdriver

2

Hi @gloebdriver. You can disable the auto-reset circuit on the board by connecting a 10 uF capacitor between the RESET and GND pins. Note that the sketch upload process relies on this auto-reset circuit to activate the bootloader, as is required to upload. So when the auto-reset circuit is disabled, you will find that uploads to the board fail unless you either manually reset the board, or else remove the capacitor before performing the upload.

Alternatively, it is possible to adjust the configuration of the board definition so that Serial Monitor will not trigger the auto-reset circuit:

https://arduino.github.io/arduino-cli/latest/platform-specification/#serial-monitor-control-signal-configuration

If you are interested in that approach and would like assistance with making the configuration, just let us know.

1 Like
3

Hi, Ptillisch,
Thanx for the quick reply.
I understand that we have to change hardware in any of the described manners. I think, this will cut any warranty, in addition to that in the Controllino Mini there is VERY LITTLE space.
But the principles behind are understood. So, no chance with a software-bend?

4

That is incorrect. The capacitor solution simply involves connecting an electrical component to the pins on the exposed header. The connection of such external circuitry is the whole reason why the designers of the "Controllino Mini" exposed those pins.

And the second solution is purely software. Did you make the effort to read the documentation I linked???

5

Thanks for the correction. I thought, we would have to modify anything on the PCB. But with the Header-pins it looks MUCH better. Will try it tomorrow.
Thanks again!