Hello everyone, I hope you are having a lovely day.
I have a design that uses the Arduino Nano Every and am going through the process of taking the schematic for the Every and integrating it into the PCB for my larger design instead of soldering on the Every as a daughterboard as I was doing before. I am doing some double checking of the design before I order boards and I want to make sure that I have all of the necessary connectors built into the board for flashing the firmware onto the MCUs in this design.
I know that normally the Arduino IDE has an option to flash the bootloader required to allow reprograming the ATMEGA4809 directly from the Arduino IDE. However my understanding is that in order for that to happen first the SAMD11, which handles the USB serial communication, would need to be flashed with a firmware that allows it to be recognized as a USB COM port and then will pass along the flashing communications to the ATMEGA.
I have seen conflicting info that the SAMD11 comes with a default firmware/ functionality installed that makes it work essentially as a USB to serial passthrough without requiring programming. I've seen this mentioned a few times on the forum but have not been able to find anything to confirm it in the admittedly quite large datasheet.
I also know that there is the 6 pin connector included in the schematic that is clearly designed for programming/ debugging the chips but I can't seem to find instructions for doing this specifically for the Arduino Nano Every. I found a few links on the forum that claim to point to instructions but the links appear to be dead, either that or the information is hidden in a submenu of the Arduino Nano Every page and I just am not eagle eyed enough to find it.
So anyways I just wanted to ask here - what is required to program the SAMD11 chip so that it can act as an adequate serial passthrough to the ATMEGA4809? Do I need to flash a firmware or does it have the correct functionality shipped with it from the start?
Here are some links to the forum posts that I am referencing:
https://forum.arduino.cc/t/how-to-burn-bootloader-on-the-nano-every-board/865169
https://forum.arduino.cc/t/things-to-know-about-developing-a-custom-nano-every/930859/2
Here is the link to the SAMD11 datasheet:
https://www.mouser.com/datasheet/2/268/Atmel_42363_SAM_D11_Datasheet-1368529.pdf
Here is a screenshot of the datasheet showing the 6 pin connector:
Thank you for your time.
