I am in need to finding the most energy-efficient Arduino-compatible MCU which also supports SPI. It will run only few lines of code and it will use SPI and only 2 GPIO pins. Nothing more. Any hint?

Most energy-efficient Arduino-compatible MCU which supports SPI

CrossRoads January 7, 2018, 10:58pm 2

Standalone 328P running from a battery.
uC, xtal, couple 22pf and 0.1uF caps, 10K reset pullup resistor.
http://www.crossroadsfencing.com/Bobuinorev17/

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