SAMD20?

I know this might be a bit of an off the wall question but I know that for the most part the SAMD20 and SAMD21 have a similar pin out. I know USB and such do not exist on the SAMD20 series part. Can I put Arduino Code on the SAMD20 using an ATMEL-ICE or SAM-ICE? I know I wouldn't be able to use the bootloader and Native USB support but that wouldn't be needed for a project I'm envisioning. I have a SAMD20 Xplained Pro board laying around but I haven't messed with it in a while. Just wondering if anyone has tried yet?

I guess that nobody here have tried it yet.

Since there is no USB on the SAMD20 I can say with confidence that if you load the bootloader provided with Arduino as-is it will not work, I don't know if it's sufficient to define:

#define SAM_BA_INTERFACE    SAM_BA_UART_ONLY

instead of

#define SAM_BA_INTERFACE    SAM_BA_BOTH_INTERFACES

to completely get rid of the USB part and make the bootloader work on SAMD20. Probably using a "stock" bootloader from Atmel is the quickest solution here.

Once the bootloader is set, you can try to blindly change the defnitions in boards.txt to match the SAMD20 and try compile the Arduino SAMD core, this test will quickly reveal two things:

  • If there are parts of the core that should be selectively included within #ifdefs (because doesn't compile on the SAMD20).
  • If, at least, the blink works.

Keep in mind that those are just "blind" suggestions, I'm not a SAMD20 expert, and I'm not sure how much the two chips are compatible (being of the same family they should be fairly compatible but... who knows...)

I think, there's no need for a bootloader at all,
since @stealthtransam wants to flash a SAMD20 with an ATEML-ICE

Exactly Dirk! I don't plan on putting a bootloader on the chip just taking the .elf, .hex, .bin, etc that is complied in the Arduino IDE and using the Atmel-ICE or SAM-ICE ( I have both) and put arduino code on the samd20.