Imports periph.io/x/periph/conn/gpio periph.io/x/periph/host/fs periph.io/x/periph/conn/gpio/gpioreg periph.io/x/periph/conn/physic periph.io/x/periph/conn/spi periph.io/x/periph/conn/spi/spireg Standard library imports errors flag fmt log math/rand time