I have some questions about the SAMD21 mini breakout board, please:
- I notice that the i2c and spi pins are not in breadboard-friendly positions for prototyping. But I also read that through some feature of the chip called SERCOM, it is possible to re-map these functions to other pins on the main 0.1" headers. Is this true, and where can I find out the details of how to achieve it?
- What is the typical current consumption in "normal" mode? What low power modes does the board/chip have, and are any of them supported by available Arduino libraries? Without removing any components, what's the minimum current I am likely to be able to achieve if (a) I just need the chip to wake after a fixed period (e.g. 15 mins) or (b) if I need it to respond to changes on certain pins (assuming that "responding" means something as simple as incrementing a count held in a variable in RAM, or perhaps reading an ADC and updating a total with the result).
- An obvious rival product would be PJRC's Teensy LC. Different chip manufacturer, but also based on ARM Cortex M0. The Teensy is priced considerably lower than the Sparkfun board. What would you say are the advantages of the Sparkfun board that would help me justify the extra?
I am currently building my first prototype node using an atmega328, but the various Arduino libraries required to use the radio module, sensors, LoRa protocols etc. mean that 90% of the atmega's flash would be used on the simplest of nodes with a single sensor.
Sparkfun SAMD21 mini:
I look forward to any advice or pointers to useful documents!