Has anyone tried modifying the Arduino Zero core to use a SAMD21E with 32-pins instead of the SAMD21G with 48-pins? I think all you'd have to do is modify the variant file, but I'm not sure if there would be more to it than that.
Scswift of the forum lauched this kickstarter campaign :
The processor is the SAMD21E17.
Oh cool. I have some of his Neutrino boards (SAMD21G18A based Arduino Zero clone), but I hadn't seen this new kickstarter with the 32-pin version. I have also seen the FemtoUSB board which features a SAMD21E18 (32k ram instead of E17 which is 16k ram), but neither of these is in production, and neither has any documention yet for getting them working in the Arduino IDE.
Really what I'm looking for is what steps I would need to take to modify the Arduino Zero core library components to get the 32-pin version in the Arduino IDE. I think it might just be the variant.cpp file, as long as I used the Atmel-ICE for programming. Otherwise I'm assuming I'd also need to modify the bootloader.
Well, at first you should compare which peripheral and component differ between samd21g and samd21e, like timer and sercom. Then, remap every pin ine the variant and remove unused one. Be sure that no lib try to use a unavailable peripheral. That's the way I would go, maybe you'll find other things to do to get it work... You could try to contact Shawn about his board, to see if you could maybe work together on this.
I found a company called MattairTech who's shipping a SAMD21E breakout, and they posted an Arduino Board Manager compatible board version (woohoo!)
Available for purchase here: https://www.mattairtech.com/index.php/development-boards/mt-d21e.html
Core files available here: https://github.com/mattairtech/ArduinoCore-samd
Arduino boards manager URL here: https://www.mattairtech.com/software/arduino/package_MattairTech_index.json