Redid formula for calculating subticks
Redid formula for calculating subticks

changed subticks calculation to give a range from 0 to 32767.
adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython