SparkFun SAMD21 Mini Breakout SPI default pins

Development Boards
1

Using SparkFun SAMD21-based Mini Breakout, DEV-13664. The v10 schematic and graphical datasheet both show SPI pins on D10-D13 as expected for an Arduino Pro Mini “default”. However, those pins are not the default in my situation. I am using Arduino IDE 1.8.13 and the SparkFun SAMD Boards package 1.8.1. I can reassign SERCOM1 to pins use D11-D13 using SPIClass and pinPeripheral assignments but the IDE/compiler does not explicitly assign those pins to the default SPI instance.

I’ve run across posts from as far back as 2015, for instance, stating “The SPI port doesn’t default to pins 10-13 on the SAMD Mini like it does on the Arduino Pro Mini” and “We’ve released an updated Arduino board package which adds an additional board definition for the Mini boards, equipping them with SPI on pins 10-13.” So I assume if I’m using up to date board definitions it should be working as expected.

My questions: Am I missing something? Should the Sparkfun SAMD Mini Breakout board configuration for Arduino IDE assign the default SPI instance to pins D10-D13?

2

Thanks for reaching out to us on this.

Your assessment seems correct; running SparkFun SAMD 1.8.1 should have the updated definitions…though they do not appear to be functional in your case. We’ll double-check to see if we accidentally reverted to an earlier revision for those boards, or something similar. In the meantime, it sounds like you are at least able to get it working, which is good!

Hope this helps, and happy sparking!

3

Thank you for the response. It appears that the variant.h file located at “…\AppData\Local\Arduino15\packages\SparkFun\hardware\samd\1.8.1\variants\SparkFun_SAMD_Mini” does indeed have the desired (D10-D13) pin assignments. I completely uninstalled/reinstalled the Arduino IDE and board definitions. The sketch is working now. Problem solved…