Go Down

Topic: How to prevent Nano Every from resetting upon connection to the serial port? (Read 208 times) previous topic - next topic

igorfier

Hello everyone,

Whenever I start the Serial Monitor to talk to my Nano Every, it resets. The tricks used to prevent this behavior on the classic Nano don't seem to work here, which are:

- 10, 100, and even 1000 uF cap between RST and GND
- 120 Ohm resistor between +5V and RST

I looked up at the schematics but it seems like the RESETN line is only connected to passive devices, so I don't see how it could be resetting the micro, to begin with.

Can you help me understand and prevent this behavior?

Thanks in advance!

pert

I don't have time to try it right now, but setting the build properties to disable the serial control signals might do it:
https://arduino.github.io/arduino-cli/latest/platform-specification/#serial-monitor-control-signal-configuration
Code: [Select]
nona4809.serial.disableDTR=true
nona4809.serial.disableRTS=true

boards.local.txt would be the ideal place to make this customization:
https://arduino.github.io/arduino-cli/latest/platform-specification/#boardslocaltxt

pert


igorfier

Hello, pert!

Thanks for the very quick replies!
Both of your proposed solutions are quite advanced to me. I have absolutely zero knowledge of the CLI and re-programming the ATSAMD11 chip, but I will look carefully into those.

Best wishes,
Igor

pert

I have absolutely zero knowledge of the CLI
The documentation I linked to is hosted in the Arduino CLI repository because it's Arduino CLI that implements these features. However, the Arduino IDE uses Arduino CLI, so all that information also applies to Arduino IDE.

Arduino CLI is a very useful tool for some purposes, but it's not required that you use it to try this out.

The summary of what it necessary to try it is to just create a file named boards.local.txt, add the text I shared in my previous reply, save that file to the same folder as the boards.txt for the Nano Every, then restart the Arduino IDE so it will recognize the file you added.

If it causes problems, you only need to delete that boards.local.txt file and you're back to where you were originally.

So the only really tricky part is finding the location of that boards.txt file.

You can do that by following these instructions:
  • Select a board from the hardware package you want to find from the Tools > Board menu
  • File > Examples > SPI > BarometricPressureSensor (or any other SPI example sketch)
  • Sketch > Show Sketch Folder
  • Move up folder levels until you reach the one that contains boards.txt


and re-programming the ATSAMD11 chip
That is definitely a more complex thing, and unfortunately there is not a lot of documentation on how to do it. I just thought I'd mention it as a possibility, but I don't necessarily recommend it. You can find information about it here:
https://www.arduino.cc/en/Guide/NANOEvery#firmware-for-samd11d14a

Go Up