First try at critical section support
First try at critical section support

adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython